136 FERC ¶ 61,185 

UNITED STATES OF AMERICA 

FEDERAL ENERGY REGULATORY COMMISSION 

Before Commissioners: Jon Wellinghoff, Chairman; 

 Marc Spitzer, Philip D. Moeller, 

 John R. Norris, and Cheryl A. LaFleur. 

Transmission Relay Loadability Reliability Standard Docket No. RM08-13-004 

ORDER NO. 733-B 

ORDER DENYING RECONSIDERATION AND GRANTING CLARIFICATION IN 

PART AND DENYING CLARIFICATION IN PART 

(Issued September 15, 2011) 

1. In this order, the Commission addresses requests for clarification or 

reconsideration of Order No. 733-A, which addressed requests for rehearing and 

clarification of our Final Rule on the North American Electric Reliability Corporation’s 

(NERC) Reliability Standard PRC-023-1 regarding “relay loadability.”1

 The petitioners 

seek further clarification of several matters that were clarified in Order No. 733-A. We 

address these requests substantively and, in part, grant clarification and, in part, deny 

requests for clarification. 

2. In addition, the petitioners seek clarification or reconsideration regarding certain 

issues arising from the Final Rule, Order No. 733 that should have been raised at an 

earlier stage of this proceeding, on rehearing. These arguments are rejected as untimely 

requests for rehearing of Order No. 733. The petitioners also seek to augment the record 

by submitting expert affidavits and request that the Commission clarify or reconsider 

Order No. 733-A in light of the supplemented record. As discussed below, we reject the 

attempt to expand the record at this late stage of the proceeding. While we reject the 

untimely arguments and affidavits on procedural grounds, we nonetheless review these 

matters in a summary manner and deny the requests on substantive grounds. 

 1

 Transmission Relay Loadability Reliability Standard, Order No. 733, 130 FERC 

¶ 61,221 (2010), order on reh’g and clarification, Order No. 733-A, 134 FERC ¶ 61,127 

(2011). 
Docket No. RM08-13-004 - 2 - 

 I. Background

3. On March 18, 2010, the Commission issued Order No. 733, which approved 

Reliability Standard PRC-023-1 (Transmission Relay Loadability) submitted to the 

Commission by NERC, the Commission-certified Electric Reliability Organization 

(ERO) for the United States. The Reliability Standard requires transmission owners, 

generator owners, and distribution providers to set load-responsive phase protection 

relays2

 according to specific criteria in order to ensure that the relays reliably detect and 

protect the electric network from all fault conditions but do not limit transmission 

loadability3

 or inhibit system operators’ ability to protect system reliability. Pursuant to 

section 215(d)(5) of the Federal Power Act (FPA),4

 the Commission directed the ERO to 

develop certain modifications to PRC-023-1 and to develop a new Reliability Standard 

that requires the use of protective relay systems that can differentiate between faults and 

stable power swings and, when necessary, phase-out relays that cannot meet this 

requirement. 

4. On February 17, 2011, the Commission issued Order No. 733-A providing 

clarifications and granting rehearing, in part, and denying rehearing, in part. Among 

other matters addressed in the order, the Commission clarified its directives to modify 

PRC-023-1 to include a mandatory test for planning coordinators to use to identify which 

facilities below 200 kV are critical to the reliability of the bulk electric system (and 

therefore subject to the Standard) and to revise Attachment A to make the Standard 

applicable to supervisory relays. Additionally, the Commission clarified a directive 

requiring NERC to develop a new Reliability Standard addressing stable power swings 

by requiring the use of protective relays that can differentiate between faults and stable 

power swings and, when necessary, phase-out relays that cannot meet this requirement. 

The Commission also offered clarification regarding the applicability of the Standard to 

backup protective relays located at a generator step-up transformer. 

 2

 Load-responsive protection relays are a category of protective relays that detect 

and initiate the removal of faults on an electric system. They are designed to read 

electrical measurements, such as current, voltage, and frequency, and can be set to 

recognize certain measurements as indicating a fault. When a protective relay detects a 

fault on an element of the system that it is protecting, it sends a signal to an interrupting 

device (such as a circuit breaker) to disconnect the element from the rest of the system. 

3

 Loadability refers to the ability of protective relays to refrain from operating 

under load conditions. 

4

 16 U.S.C. § 824o(d)(5) (2006). 
Docket No. RM08-13-004 - 3 - 

5. In addition, Order No. 733-A articulated the structure established by section 215 

of the FPA by which the Commission, and not solely the ERO, has the responsibility and 

authority to identify reliability gaps. The ERO is authorized to address reliability matters 

through its Reliability Standards development process, and the Commission through its 

review of proposed Reliability Standards and authority to direct modifications or new 

Standards that address specific issues necessary to carry out the purposes of section 215. 

II. Request for Clarification of Reconsideration

6. On March 21, 2011, the Edison Electric Institute and the National Rural Electric 

Cooperative Association (collectively, EEI/NRECA) jointly filed a timely motion and the 

American Public Power Association and the Transmission Access Policy Study Group 

(collectively, APPA/TAPS) together filed a motion, in both instances, requesting 

clarification or reconsideration of Order No. 733-A.5

 

7. In general, both motions assert the Commission based its directives on a faulty 

understanding of the Blackout Report6

 or an incorrect characterization of relay 

engineering. Both motions also reprise issues addressed in Order No. 733-A relating to 

the Commission exceeding its statutory authority by failing to give “due weight” to the 

technical expertise of the ERO and by giving overly prescriptive directives. Finally, 

EEI/NRECA seek clarification or reconsideration of language that they characterize as 

suggesting that the Commission expects 100 percent relay security and of the 

Commission’s directive regarding generator relays. 

III. Discussion

8. Below, we address the following five matters that are appropriately before us as 

requests for clarification of Order No. 733-A: (1) stable power swings; (2) due weight to 

the ERO; (3) scope of Commission directives; (4) expected relay performance; and 

(5) relays located at generators. On these matters, we grant clarification, in part, and 

deny clarification, in part. 

 5

 EEI/NRECA March 21, 2011 Joint Request for Clarification at 1 (EEI/NRECA 

Request); APPA/TAPS March 21, 2011 Motion at 1 (APPA/TAPS Motion). 

EEI/NRECA and APPA/TAPS are collectively referred to herein as the Trade 

Associations. 

6

 U.S.-Canada Power System Outage Task Force, Final Report on the 

August 14, 2003 Blackout in the United States and Canada: Causes and 

Recommendations (Apr. 2004) (Blackout Report), available at

https://reports.energy.gov/BlackoutFinal-Web.pdf. 
Docket No. RM08-13-004 - 4 - 

9. In addition, certain arguments raised in the requests for clarification and/or 

reconsideration do not pertain to clarifications made by the Commission in Order 

No. 733-A. Likewise, EEI/NRECA submit two affidavits to support their pleadings. As 

discussed below, we reject the untimely pleadings and affidavits on procedural grounds. 

As we explain, however, even if these pleadings and affidavits were properly before us, 

they would not cause us to revisit our previous decisions.7

A. Stable Power Swings

10. Reliability Standard PRC-023-1 applies to steady state8

 relay loadability without 

regard to dynamic conditions or stable power swings.9

 Rather than ordering the ERO to 

modify PRC-023-1 to address stable power swings, Order No. 733 directed the ERO to 

develop a new Reliability Standard that requires the use of protective relay systems that 

can differentiate between faults and stable power swings and, when necessary, phase-out 

relays that cannot meet this requirement. In Order No. 733-A, the Commission 

reaffirmed its belief that not addressing stable power swings constitutes a gap in the 

current Reliability Standards, clarified its expectations regarding phasing-out zone 3 

relays,10 and affirmed that the ERO has flexibility in how it addresses the directive. 

 

(continued...) 

7

 We address the arguments in these pleadings and affidavits on the merits below, 

in a section titled “Untimely Arguments.” 

8

 The steady state of a power system is an operating condition assumed for 

analysis purposes in which all the operating quantities that characterize the system’s 

operating condition can be considered to be constant. As stated in the Blackout Report 

on page 76, “[t]he electric power system constantly experiences small power oscillations 

that do not lead to system instability.” As a practical matter, therefore, the power system 

never achieves a steady state condition because there are always movements or changes 

in power flows, voltages or frequencies simply due to load ramping, generation 

dispatches, planned or unplanned removal of facilities, and tripping or inadvertent 

tripping of facilities due to system disturbances. 

9

 Stable power swings are oscillations in power flow(s) on an electric system that 

do not result in instability and arise from an event or disturbance such as changes in load, 

scheduled or unscheduled removal of transmission or generation facilities, or a fault. 

10 Reliability Standard PRC-023-1 addresses Recommendation 21A of the 

Blackout Report, which pertains to zone 3 relays. The most common system protective 

device for transmission lines is the impedance relay, also known as a distance relay. A 

protective system using distance relays consists of two or three relays, each of which 

looks at a particular “zone” of the transmission line. Zone 3 relays, and zone 2 relays set 
Docket No. RM08-13-004 - 5 - 

11. EEI/NRECA assert the Blackout Report does not support the need for a Reliability 

Standard addressing stable power swings. They believe the Blackout Report neither 

recommends that such a Standard be created, nor does its analysis support such a 

Standard. According to EEI/NRECA, relays tripped during the August 2003 Blackout 

not because of the inability of relays to distinguish faults from stable power swings, but 

because of faults and severe over-loading conditions without faults. In response to the 

Commission’s statement regarding protection system applications currently used to block 

tripping of relay elements during stable power swings,11 EEI/NRECA identify technical 

limitations of certain protection schemes mentioned by the Commission in Order 

No. 733-A. They claim that a Reliability Standard that requires relays to distinguish 

between stable power swings and faults threatens to decrease Bulk-Power System 

reliability.12 Finally, they assert that the Commission has inserted “dynamic 

loadability” conditions into PRC-023-1 thus introducing “a concept unknown in the 

industry” and contradicting the intent of the Reliability Standard. For these reasons, the 

Trade Associations seek clarification of the rationale supporting the directives. 

Commission Determination

12. The Commission addressed this issue in both Order Nos. 733 and 733-A13 and is 

not persuaded that further clarification is necessary. The Blackout Report summarizes 

 

to operate like zone 3 relays (zone 3/zone 2 relays), can provide remote circuit breaker 

failure and backup protection for remote distance faults on a transmission line. These 

relays are typically set to reach 100 percent of the protected transmission line with a 

margin of more than 100 percent of the longest line (including any series elements such 

as transformers) that emanates from the remote buses. The zone 3/zone 2 relay trips 

when the apparent impedance (measured by the current and voltage seen by the relay) 

falls within a designated zone for a specified length of time. In tripping, it causes circuit 

breakers to operate and thereby isolates the protected elements. Blackout Report at 74; 

Order No. 733, 130 FERC ¶ 61,221 at P 4 n.8. 

11 “We also believe that [the] claim that relays cannot distinguish between actual 

faults and stable power swings appears to ignore the fact that there are protection system 

applications currently in use for such purposes, i.e., ‘power swing block’ applications that 

are applied to block tripping of distance relay elements during stable power swings.” 

Order No. 733-A, 134 FERC ¶ 61,127 at P 112 (footnote omitted). 

12 EEI/NRECA Request at 13–14. 

13 Order No. 733, 130 FERC ¶ 61,221 at P 130–173; Order No. 733-A, 134 FERC 

¶ 61,127 at P 100–113. 
Docket No. RM08-13-004 - 6 - 

how the August 2003 Blackout cascade was triggered, identifies the role played by zone 

3/zone 2 relays operating unnecessarily when faults did not exist,14 and recommends 

addressing the problem of such relays tripping unnecessarily.15 It takes no position, 

however, on whether to address the problem based on either a steady-state loading 

approach or a stable power swings approach. Had the Blackout Report taken a position 

as to how to address the problem of relays tripping unnecessarily, the Commission would 

nevertheless be authorized by section 215(d)(5) of the FPA to identify gaps in reliability 

and direct the ERO to submit a new Reliability Standard or a modification to an existing 

Standard to address such gaps. The ERO designed Reliability Standard PRC-023-1 to 

address the steady-state aspects of relay loadability,16 but did not address the aspects of 

the problem associated with stable power swings. The Commission identified the failure 

to address stable power swings as a gap in the current Reliability Standards that must be 

addressed and directed that it be addressed in a separate Reliability Standard.17 

13. As we explained in Order No. 733, the Commission’s concern that stable power 

swings should not cause unnecessary relay operations is consistent with good planning 

practices and considerations as documented by the NERC’s predecessor, the North 

American Electric Reliability Council.18 According to its published NERC Planning 

Standards approved by the ERO’s predecessor’s Board of Trustees in 1997, good 

planning practice dictates that protection design systems are to be designed to have 

generation and transmission protection systems avoid tripping for stable power swings on 

the interconnected transmission system.19

14. EEI/NRECA assert that the August 2003 Blackout was the result of severe overloading conditions and not the result of an inability on the part of relays to distinguish 

faults from stable power swings. The general nature of their assertion suggests that lines 

tripped because the current exceeded the lines’ ratings just as a household circuit breaker, 

which is sensitive only to current, trips to prevent thermal damage. But, in fact, 

 14 Blackout Report at 73. 

15 Id. at 158. 

16 See Order No. 733, 130 FERC ¶ 61,221 at P 132, 173. 

17 Id. P 150–153; Order No. 733-A, 134 FERC ¶ 61,127 at P 104. 

18 Order No. 733, 130 FERC ¶ 61,221 at P 151. 

19 North American Electric Reliability Council, NERC Planning Standards 49 

(1997). 
Docket No. RM08-13-004 - 7 - 

transmission lines can tolerate thermal heating for limited periods without experiencing 

problems.20 Moreover, based on steady-state load flow analysis, the Blackout Report 

indicates the Sammis-Star line, loss of which marked the turning point at which system 

problems initiated a cascade, only encountered loading above 120 percent of its normal 

rating21 but tripped because its protective relays registered low apparent impedance.22

15. The Blackout Report details how, upon the initial tripping of FirstEnergy’s lines, 

the redistributed power flows increased the current flowing over the remaining 

operational lines, thus, aggravating voltage declines.23 Because current increases in 

inverse proportion to the decrease in voltage for a given amount of power, as the current 

rose, the voltage on the lines fell. Zone 3/zone 2 relays, looking for line faults, operated 

when the apparent impedance (voltage divided by current) seen by the relays fell within 

one of the relays’ operating zones for the appropriate amount of time delay.24 Once lines 

in the Cleveland-Akron area tripped, the disrupted power flow on these tripped lines were 

redistributed to other lines including critical 345 kV lines in Michigan, in turn causing 

depressed voltages and increased currents which, when seen by zone 3/zone 2 relays, led 

to further tripping of lines.25 Based on these facts, an assertion that the lines tripped 

simply because of overloading in the absence of stable power swings would represent an 

incomplete picture. Instead, the Blackout Report states that “[p]ower swings and voltage 

 20 North American Electric Reliability Council, NERC Actions to Prevent and 

Mitigate the Impacts of Future Cascading Blackouts 12 (February 10, 2004) (NERC 

Actions Report), reprinted in Blackout Report, Appendix D, at 204 (“Many of the zone 3 

relays that operated during the August 14 cascading outage were not set with adequate 

margins above their emergency thermal ratings. For the short times involved, thermal 

heating is not a problem and the lines should not be tripped for overloads.”); see also

Blackout Report at 82. 

21 Blackout Report at 64 fig. 5.12. 

22 Id. at 69 (“Unlike the previous three 345-kV lines, which tripped on short 

circuits to ground due to tree contacts, Sammis-Star tripped because it protective relays 

saw low apparent impedance (depressed voltage divided by abnormally high line 

current)—i.e., the relay reacted as if the high flow was due to a short circuit.”). 

23 Id. at 81. 

24 Id. at 80. 

25 Id. at 75. 
Docket No. RM08-13-004 - 8 - 

fluctuations . . . can cause other lines to detect high currents and low voltage that appear 

to be faults, even if faults do not actually exist on these other lines.”26

16. Moreover, the North American Electric Reliability Council acknowledged the role 

of power swings in the misoperation of relays during the August 2003 Blackout. In its 

Recommendation 8 appended to the Blackout Report in Appendix D, it acknowledged the 

role power swings played in causing zone 3 relays to operate for overload conditions: 

First, beginning with the Sammis-Star line trip, most of the remaining line 

trips during the cascade phase were the result of the operation of a zone 3 

relay for a perceived overload (a combination of high amperes and low 

voltage) on the protected line. If used, zone 3 relays typically act as an 

overreaching backup to zone 1 and zone 2 relays, and are not intentionally 

set to operate on a line overload. However, under extreme conditions of 

low voltages and large power swings as seen on August 14, zone 3 relays 

can operate for overload conditions and propagate the outage to a wider 

area by essentially causing the system to “break up.”27 

In response to the Commission’s request for comment on whether the ERO should 

develop a modification to PRC-023-1 or a separate Reliability Standard to address stable 

power swings, NERC replied, in part, that “[r]eliability of the power system requires 

secure protective relay settings to avoid operation during stable power swings and 

dependable tripping for faults and unstable power swings. . . . FERC is appropriately 

concerned with the effect of stable power swings upon load responsive relays.”28 And in 

a document that the ERO described as representing the technical justification for ongoing 

revisions to the Reliability Standard addressing coordination of system protection among 

operating entities,29 NERC’s System Protection and Control Subcommittee states “[t]he 

 26 Id. at 73. 

27 NERC Actions Report at 12, reprinted in Blackout Report at 204 (emphasis 

added). 

28 North American Electric Reliability Corp. August 17, 2009 Comments in 

Response to Notice of Proposed Rulemaking (NERC Comments) Docket No. RM08-13-

000, at 24–25 (emphasis added). 

29 Id. at 21. 
Docket No. RM08-13-004 - 9 - 

impedance relay must not operate for stable system swings.”30 The Commission’s 

directive is, therefore, supported by the record and is not arbitrary and capricious.31 

17. In response to the Commission’s Notice of Proposed Rulemaking,32 some 

commenters disputed the value of the protection schemes capable of distinguishing 

between faults and stable power swings mentioned by the Commission, and argued that 

the applications identified by the Commission were less reliable than the methods used in 

distance relays. In Order No. 733, we noted that the protection systems discussed in the 

NOPR were merely examples of systems that can differentiate between faults and stable 

power swings. Regarding the Trade Associations’ concern that the directive may result 

in reduced reliability, we repeat what we responded to those NOPR commenters in Order 

No. 733: “We leave it to the ERO to determine the appropriate protection systems to be 

discussed in the new Reliability Standard through application of its technical 

33 expertise.” 

 during 

ulting 

from Category B and Category C contingencies) that will result in inappropriate 

 

18. Our directive does not require the elimination of the currently used impedance (or 

distance) relays as backup protection. Nor does it mandate use of a particular technology 

or an absolute obligation to prevent protection relays from operating unnecessarily

power stable swings. Our directive instead requires “the creation of a Reliability 

Standard that addresses protection systems vulnerable to stable power swings (res

30 North American Electric Reliability Corp., Technical Reference Document, 

Power Plant and Transmission System Protection Coordination 26 (2009) (emphasis 

added) (subsequently revised in July 2010 without alteration to cited material). 

31 The ERO has continued to support the reliability objective associated with 

developing a Reliability Standard to address operation of protective relays in response to 

stable power swings. North American Electric Reliability Corporation, Informational 

Filing in Response to Order No. 733-A on Rehearing, Clarification, and Request for an 

Extension of Time, Docket No. RM08-13-000 at 7 (filed July 21, 2011) (NERC 

Informational Filing). 

32 Transmission Relay Loadability Reliability Standard, Notice of Proposed 

Rulemaking, FERC Stats. & Regs. ¶ 32,642 (2009) (NOPR). 

33 Order No. 733, 130 FERC ¶ 61,221 at P 167; see also Order No. 733-A, 134 

FERC ¶ 61,127 at 108 (“[t]hrough the application of its technical expertise, and the 

balancing of stakeholder interests, the ERO’s Reliability Standard development process is 

the appropriate forum to discover and address any unintended consequences arising from 

the use of protective relays systems”). 
Docket No. RM08-13-004 - 10 - 

tripping.”34 A new Reliability Standard addressing stable power swings will interact with 

existing Facilities Design, Connections and Maintenance (FAC), Interconnection 

Reliability Operations and Coordination (IRO), Protection and Control (PRC), 

Transmission Operations (TOP), and Transmission Planning (TPL) Reliability Standards. 

These Reliability Standards interact to promote Reliable Operations. As we said in Order 

No. 733: 

these interactions require limits to be established for all system elements, 

interconnected systems to be operated within these limits, operators to take 

immediate action to mitigate operation outside of these limits, and 

protective relays to refrain from operating until the observed condition on 

their protected element exceeds these limits. Protection relays include 

primary and backup relays. If zone 2/zone 3 relays are used by entities as 

part of their protection systems designed to achieve the system 

performance, they can remain as backup protection as long as they do not 

inadvertently trip non-faulted facilities due to stable power swings.35

19. As to EEI/NRECA’s assertion that our directive contradicts the intent of the 

Reliability Standard by inserting dynamic-related criteria into PRC-023-1, we note that 

our directive was to fill a gap not intended to be covered by this Reliability Standard by 

creating a new Reliability Standard to address stable power swings. In its response to the 

NOPR, NERC commented that rather than modifying PRC-023-1, stable power swings 

should be addressed in a separate Reliability Standard.36 NERC further requested that we 

provide the ERO adequate time to undertake the effort to develop requirements that 

promote the overall reliability of the power system while avoiding unintended 

consequences. The Commission, accordingly, did not direct that stable power swings be 

addressed in PRC-023-1. Instead, we agreed with the ERO that this subject could 

appropriately be handled in a separate Reliability Standard and directed the ERO to 

submit an action plan and timeline to address this issue. 

20. Therefore, based on the rationale provided above, we do not provide the 

clarification sought by the Trade Associations. 

 34 Order No. 733-A, 134 FERC ¶ 61,127 at 107. 

35 Order No. 733, 130 FERC ¶ 61,221 at P 166. 

36 NERC Comments at 25. 
Docket No. RM08-13-004 - 11 - 

B. Due Weight

 Order No. 733-A

21. In Order No. 733-A, the Commission reaffirmed that the ERO has discretion in 

how to comply with a Commission directive.37 The Commission explained that “[t]he 

ERO is not required to adopt the Commission’s guidance into the Reliability Standard, 

but is required to develop its response to the Commission’s concerns through the 

stakeholder evaluation process contained within the Reliability Standard development 

process.”38 

22. In discussing concerns raised on rehearing regarding the Commission’s 

application of due weight, the Commission explained: 

We find no difficulty in reading section 215(d)(2) in harmony with section 

215(d)(5). Section 215(d)(2) requires the Commission to give due weight 

to the technical expertise of the ERO when the Commission reviews a 

Standard or modification proposed by the ERO. Section 215(d)(5) 

authorizes the Commission to direct a modification to a Standard if it 

judges that such a modification is necessary. There is no contradiction in 

the Commission giving due weight to the technical expertise of the ERO 

and still finding that there is a “specific matter” that the ERO must address. 

EEI’s argument tends to diminish the significance of the Commission’s 

authority to direct modifications under section 215(d)(5) because it fails to 

recognize that the Commission, and not just the ERO, has the responsibility 

and authority to identify “specific matters” that it considers appropriate to 

carry out section 215. Section 215 establishes a paradigm by which both 

the Commission and the ERO are responsible for identifying reliability 

gaps—the ERO through its Reliability Standards development process, 

where it can independently identify areas of concern and develop Standards 

to address them; and the Commission through its review of proposed 

Reliability Standards and authority to direct modifications or new 

Standards that address specific issues necessary to effectuate the purposes 

of section 215.39

 37 Order No. 733-A, 134 FERC ¶ 61,127 at P 12; see generally id. “Authority 

Under Section 215(d) of the FPA” at P 8–30. 

38 Id. P 12. 

39 Id. P 25 (citation omitted); see also id. P 23–27. 
Docket No. RM08-13-004 - 12 - 

Requests for Clarification

23. EEI/NRECA state that an essential part of the reliability regime established by 

section 215 of the FPA is the requirement that the Commission give due weight to the 

technical expertise of the ERO. They argue that the Commission failed to give due 

weight to the ERO’s technical expertise regarding how to address the transmission relay 

loadability concerns raised in the Blackout Report. EEI/NRECA contend that the 

Commission’s directives in this proceeding necessarily determined that the ERO had not 

sufficiently addressed the recommendations of the Blackout Report on loadability issues. 

But, they argue, “where the ERO has proposed a rational technical basis for why the 

proposed Reliability Standard meets the purpose of the Standard, the obligation to give 

‘due weight’ should act to prevent the Commission from second-guessing the conclusions 

of the ERO, even if the Commission believes it would have proposed a different 

Reliability Standard.”40 

24. EEI/NRECA further assert that a directive begins with a determination that the 

proposed Reliability Standard is technically deficient, thus, overruling the ERO’s 

conclusions on the proper way to protect the Bulk-Power System. EEI/NRECA contend 

that, the Commission’s duty to give due weight to the ERO’s expertise requires that “the 

Commission must respect the technical expertise of the ERO not only in how to address 

the underlying concern, but also with regards [sic] to whether there is an additional 

underlying concern on that issue that needs to be addressed.”41 

25. According to EEI/NRECA, a proposed Reliability Standard is the product of the 

ERO’s technical judgment with respect to both what it contains and what it omits. With 

this premise, any directive addressing the context of the proposed Standard must 

overcome the obligation to accord due weight to the ERO’s technical judgment. 

Accordingly, EEI/NRECA argue that Order No. 733-A errs in asserting that the 

Commission’s authority to direct a modification under section 215(d)(5) of the FPA is 

not constrained by the requirement in section 215(d)(2)42 that it give due weight to the 

technical expertise of the ERO.43 

 40 EEI/NRECA Request at 22. 

41 Id. at 25. 

42 16 U.S.C. § 824o(d)(2) (2006). 

43 Order No. 733-A, 134 FERC ¶ 61,127 at P 25. 
Docket No. RM08-13-004 - 13 - 

26. In giving guidance with respect to a specific directive, the Commission has stated 

that it will consider an alternative provided that the ERO can show that its alternative 

addresses the Commission’s underlying reliability concern in an equally efficient and 

effective manner as the Commission’s suggested approach.44 For the Trade Associations, 

the requirement that the ERO’s alternative approach must be equally effective and 

efficient as the Commission’s proposal is not supported by Section 215, and adds 

additional and unwarranted restrictions on the ERO’s statutory role.45

Commission Determination

27. We deny the EEI/NRECA request for clarification on this issue. While 

EEI/NRECA add some new nuance to the matter, their petition essentially revisits a 

matter that we have adequately addressed previously in this and other Commission 

proceedings.46 However, we address the matter below because of the ongoing concern 

regarding the Commission’s authority to issue directives pursuant to section 215(d)(5) of 

the FPA and how that dovetails with another statutory provision that the Commission 

give “due weight” to the ERO’s technical expertise. 

28. Section 215(d)(5) of the FPA grants the Commission the authority to direct the 

ERO to develop a Reliability Standard or a modification to a Reliability Standard that 

addresses a specific matter if the Commission considers such a new or modified 

Reliability Standard appropriate.47 While EEI/NRECA are correct in stating that the 

Commission must give due weight to the technical expertise of the ERO when the 

Commission reviews a Standard or modification proposed by the ERO, their argument 

fails to recognize that the Commission, upon its own motion, is authorized to identify 

matters it considers appropriate to carry out section 215. The Commission has the 

 44 Id. P 13; Order No. 733, 130 FERC ¶ 61,221 at P 18. 

45 EEI/NRECA Request at 23; APPA/TAPS Motion at 5. 

46 See Order No. 733-A, 134 FERC ¶ 61,127 at P 8–12, 22-27; see also Revision 

to Electric Reliability Organization Definition of Bulk Electric System, Order No. 743-A, 

134 FERC ¶ 61,210, at P 14–16, 26–31 (2011); North American Electric Reliability 

Corp.,132 FERC ¶ 61,218, at P 30–36, 53 (2010). 

47 Section 215(d)(5) of the FPA states: “The Commission, upon its own motion 

or upon complaint, may order the Electric Reliability Organization to submit to the 

Commission a proposed reliability standard or a modification to a reliability standard that 

addresses a specific matter if the Commission considers such a new or modified 

reliability standard appropriate to carry out this section.” 
Docket No. RM08-13-004 - 14 - 

responsibility and authority to identify specific matters that it considers appropriate to 

carry out section 215.48 

29. We are not persuaded by EEI/NRECA’s argument that a proposed Reliability 

Standard is owed due weight both to the matters addressed in the Standard and to related 

matters that are omitted from the Standard without any explanation in the record. The 

petitioners’ approach is incongruous with the language of section 215(d)(2) of the FPA, 

which states that “the Commission shall give due weight to the technical expertise of the 

Electric Reliability Organization with respect to the content of a proposed standard or 

modification to a reliability standard...” (emphasis added). EEI/NRECA argue that an 

unexplained omission is an exercise of the ERO’s technical expertise and thus entitled to 

due weight. We disagree, and find that it is unreasonable to read the statute as requiring 

the Commission to give due weight to an omission when there is no evidence in the 

record to explain that omission. Without such evidence, the Commission would have no 

basis for evaluating the reasoning behind the omission or for determining whether the 

omission prevented the proposed Reliability Standard from satisfying the statutory 

standard of review. Thus, the Commission must give due weight to an omission when 

the ERO explains the technical basis behind the omission in an initial filing, response to a 

Commission data request, supplemental filing, comments on a notice of proposed 

rulemaking, or other filing in the record. We do not read section 215(d)(2) as requiring 

the Commission to give due weight to an unexplained omission, especially in 

circumstances where, as here, the Commission identifies the omission as an area of 

concern and provides the ERO with an opportunity to comment on whether the concern is 

justified, and if so, whether the Commission’s proposed remedy is appropriate. 

Consequently, we reject EEI/NRECA’s argument. 

30. Moreover, EEI/NRECA imply that the due weight owed the ERO prevents the 

Commission from issuing directives to augment or modify a Standard. We disagree with 

any such implication. We believe it is important to explain the Commission’s application 

of due weight, as well as its section 215(d)(5) authority, in the context of this proceeding. 

In Order No. 733, the Commission directed the ERO to develop a new or modified 

Reliability Standard to address several concerns identified by the Commission. For 

example, Reliability Standard PRC-023 does not address stable power swings. The 

Commission found that this omission constitutes a reliability gap and directed the ERO to 

develop a new Standard that addresses this matter.49 Furthermore, in its comments in 

response to the reliability gap identified by the Commission in the NOPR, the ERO 

 48 Order No. 733-A, 134 FERC ¶ 61,127 at P 25. 

49 Order No. 733, 130 FERC ¶ 61,221 at P 150; Order No. 733-A, 134 FERC 

¶ 61,127 at P 104. 
Docket No. RM08-13-004 - 15 - 

affirmed the need to address stable power swings.50 In this circumstance, it is reasonable 

for the Commission to exercise its section 215(d)(5) authority to direct the ERO to 

develop a new or modified Reliability Standard that addresses the Commission’s concern. 

31. Similarly, Reliability Standard PRC-023-01 states that the Standard applies to 

transmission lines operated at 200 kV and above and “transmission lines operated at 100 

kV to 200 kV as designated by the Planning Coordinator as critical to the reliability of the 

Bulk Electric System.”51 The Reliability Standard, however, does not provide any 

criteria for defining or identifying transmission lines that are “critical” to reliability. In 

its comments on the NOPR, NERC submitted its guidance for identifying operationally 

significant 100kV–200kV facilities, but after careful review and giving due weight to the 

ERO’s submission, the Commission concluded that the guidance would identify some, 

but likely not all, critical sub-200 kV facilities. In particular, the Commission found that 

while NERC’s guidance would identify all critical facilities between regions and subregions, it would not necessarily identify the critical facilities within a sub-region or a 

company.52 In light of this, the Commission directed the ERO pursuant to section 

215(d)(5) of the FPA, to develop a mandatory test to identify which sub-200 kV facilities 

could trip on relay loadability and contribute to a cascading outage.53 The Commission’s 

Final Rule also articulated what an appropriate set of criteria would accomplish and a 

suggested set of criteria for determining “critical” transmission lines in the 100 kV to 200 

kV range. The Commission, however, made clear that other approaches would be 

acceptable provided that they satisfied the underlying reliability concerns. Again we 

believe that this is an appropriate exercise of the Commission’s 215(d)(5) authority, and 

does not deny due weight to the ERO’s technical expertise.54

32. In another exercise of its section 215(d)(5) authority, the Commission directed the 

ERO to modify PRC-023-1 by removing supervisory relays from Attachment A’s list of 

 50 See NERC Comments at 24. 

51 PRC-023-1 A.4.1.2. 

52 Order No. 733, 130 FERC ¶ 61,221 at P 75-76. 

53 Order No. 733-A, 134 FERC ¶ 61,127 at P 39, citing Order No. 733, 130 FERC 

¶ 61,221 at P 69. 

54 The ERO acknowledged the need for some criteria in its comments on the 

NOPR. See NERC Comments at 12 (“NERC recognizes the need for consistent criteria 

across North American [sic] for making these determinations regarding 100 kV to 200 

kV circuits.”). 
Docket No. RM08-13-004 - 16 - 

protection systems excluded from the requirements of the Reliability Standard. The 

Commission, however, made it clear that it did not prescribe this specific change as an 

exclusive solution to its reliability concern.55 The ERO gave no technical rationale for 

the exclusion in its initial filing, but in response to the NOPR justified the exclusion on 

the basis that it is preferable to trip one line for loss of communications than not to trip 

the line at all.56 In this instance, the Commission, after giving due weight to the ERO’s 

technical expertise, was not persuaded that the ERO had offered a reasonable rationale 

for the exclusion of supervisory relays.57 Even with this concern, the Commission 

determined that the proposed Reliability Standard PRC-023-1 was just and reasonable, 

not unduly discriminatory or preferential and in the public interest, and approved the 

Standard. However, as a separate matter, the Commission exercised its authority 

pursuant to section 215(d)(5) of the FPA and directed the ERO to address the 

Commission’s concern regarding supervisory relays. 

33. We disagree with the Trade Associations’ argument that the Commission is adding 

an unwarranted restriction on the ERO by requiring any alternative to its guidance to be 

“equally effective and efficient” as the Commission’s suggested approach. The 

Commission addressed this same issue raised by NRECA in another docket. Our Order 

No. 743-A noted that section 215(d)(2) of the FPA establishes the standard of review the 

Commission is to use in reviewing the content of an ERO proposed Reliability 

Standard.58 The statute specifies that the “Commission may approve, by rule or order, a 

proposed reliability standard or modification to a reliability standard if it determines that 

the standard is just, reasonable, not unduly discriminatory or preferential, and in the 

public interest.59 The Commission then dismissed NRECA’s argument by stating: 

Certainly, whether a proposed Reliability Standard provides for an adequate 

level of reliability is included in the factors used in determining whether the 

proposal is just and reasonable, but it is not the standard of review. The 

Commission’s statement that any alternative proposal must be “as effective 

 55 Order No. 733, 130 FERC ¶ 61,221 at P 264. 

56 NERC Comments at 35. 

57 See Order No. 733, 130 FERC ¶ 61,221 at P 267–269 (explaining the 

Commission’s concerns regarding the exclusion of supervisory relays). 

58 Revision to Electric Reliability Organization Definition of Bulk Electric System, 

Order No. 743-A, 134 FERC ¶ 61,210, at P 14 (2011). 

59 16 U.S.C. ¶ 824o(d)(2). 
Docket No. RM08-13-004 - 17 - 

as, or more effective than, the Commission’s proposed approach” must not 

“result in a reduction in reliability” provides guidance regarding the 

Commission’s view of what is necessary to produce not only an adequate 

level of reliability but also a result that accords with the section 215(d)(2) 

review criterion.60 

34. Accordingly, for the reasons discussed above, we deny the Trade Associations’ 

request for clarification on this issue. 

C. Scope of Commission Directives

35. In Order No. 733-A, the Commission addressed arguments on rehearing that Order 

No. 733 prescribed the specific technical content of certain modifications and, thereby, 

exceeded the Commission’s authority. In response, the Commission clarified in Order 

No. 733-A that it did not require the ERO to adopt the precise content of Commission 

guidance in order to satisfy the concern identified by the Commission.61 Rather, the 

guidance was given to inform the ERO and industry as to the underpinnings of the 

Commission’s concerns.62 

36. APPA/TAPS ask the Commission to clarify that its directive to make Reliability 

Standard PRC-023-1 applicable to supervisory relays does not foreclose the ERO 

developing a more tailored approach to addressing the Standard’s applicability. 

37. The Trade Associations assert that the scope of the directives clarified in Order 

No. 733-A belies the Commission’s claim that the ERO has discretion in how it addresses 

the Commission’s underlying reliability concern. The directives, EEI/NRECA claim, 

direct the ERO how to address the Commission’s concerns and in so doing, exceed the 

statutory authority of the Commission to grant directives on a “specific matter.” For 

example, according to EEI/NRECA, rather than simply state its concern that reliability is 

compromised by excluding supervisory relays from the scope of PRC-023-1, the 

Commission directed the ERO to (1) remove the exclusion of supervisory relays from the 

Reliability Standard, and (2) add supervisory relays to the list of protective functions 

described as within the scope of the Standard. 

38. EEI/NRECA point to the directive to develop a test to determine sub-200 kV 

critical assets as another example in which the Commission restricted the ERO’s 

 60 Order No. 743-A, 134 FERC ¶ 61,210 at P 16 (citations omitted). 

61 E.g., Order No. 733-A, 134 FERC ¶ 61,127 at P 10–13, 23, 48. 

62 Id. P 12. 
Docket No. RM08-13-004 - 18 - 

discretion by identifying specific elements that it would consider appropriate for such a 

test. They argue that although the Final Rule explicitly provides room for discretion, the 

ERO remains constrained by the Commission’s restrictions on the manner in which it is 

permitted to address the Commission’s underlying concerns. EEI/NRECA argue that, by 

so limiting the ERO’s scope to address an identified reliability concern, the Commission 

exceeded its authority under the FPA and impinged on the ERO’s authority to draft and 

propose Reliability Standards. 

Commission Determination

39. In response to APPA/TAPS, we clarify our directive pertaining to supervisory 

relays. In Order No. 733-A, the Commission discussed its directive to make supervisory 

relays subject to Reliability Standard PRC-023-1 and stated: 

As discussed in Order No. 733, and previously in this section, the 

Commission is concerned with supervisory relays set below the rating of 

the line being continuously energized and thus no longer able to act as a 

check on the protection system the relays are supervising. . . . The ERO did 

not provide any technical rationale for excluding any load responsive phase 

protection systems from the requirements of PRC-023-1. Having directed 

the ERO to modify PRC-023-1 in a specific manner, we will accept an 

alternative method that addresses the Commission’s concern provided such 

alternative is demonstrably adequate in addressing the Commission’s 

underlying concern as efficiently and effectively as the Commission’s 

proposal.63

The Commission clarifies that its directive regarding the applicability of the 

Reliability Standard to supervisory relays does not foreclose the development of 

an approach tailored to eliminate application of the standard to some supervisory 

relays but not to others, where technically justified.64 In other words, the revised 

standard only need apply to a subset of supervisory relays. 

 63 Id. P 133-134. 

64 Concurrent with the issuance of this order, we are also issuing a Notice of 

Proposed Rulemaking in Docket No. RM11-16-000, pertaining to NERC’s proposed 

revisions to Reliability Standard PRC-023-2. In that proceeding, the Commission 

proposes to approve NERC’s modified Reliability Standard, which includes a provision 

pertaining to supervisory relays. See Transmission Relay Loadability Reliability 

Standard, Notice of Proposes Rulemaking, 136 FERC ¶ 61,187 at P 28-29, 39 (2011). 
Docket No. RM08-13-004 - 19 - 

40. The Commission declines to grant clarification as to the other issues raised 

regarding the scope of the Commission’s directives. EEI/NRECA’s arguments seem to 

presuppose that the use of the term “specific matter” in section 215(d)(5) necessarily 

means a single, unitary matter.65 Thus, they argue that the Commission should have 

articulated its concern regarding a test for sub-200 kV facilities as a single issue: the lack 

of a uniform test for critical sub-200 kV facilities. Instead, the Commission articulated 

its concern as follows: 

[I]n order to provide the necessary assurance that the Standard would 

achieve its purpose, the test must include or be consistent with the system 

simulations and assessments that are already required by the existing TPL 

Reliability Standards, meet the system performance levels for all Category 

of Contingencies used in transmission planning, set forth some definition of 

desirable system performance, and describe the steady state and dynamic 

base cases that the planning coordinator must use in identifying facilities in 

the 100 kV to 200 kV range that are subject to PRC-023-1.66 

As we said in Order No. 733-A, these are the elements that constitute the Commission’s 

reliability concern. When the Commission’s concern is manifold, it serves no purpose to 

pretend it is simple and deny the ERO the ability to understand the full extent of the 

Commission’s concern. If the Commission foregoes giving a precise statement of its 

concern, the ERO may not know how to appropriately respond.67 

41. We find our view to be consistent with the statutory language that authorizes the 

Commission to order the ERO to submit a new Reliability Standard or a modification to 

address a “specific matter” the Commission considers appropriate. If the Commission 

were to adopt the Trade Associations’ reading of the statute, the Commission would be 

constrained to articulate its reliability concerns such as those quoted above one at a time, 

thus compelling an inefficient succession of directed modifications to the Reliability 

Standard. 

D. Expectation as to Relay Operation

42. EEI/NRECA seek clarification as to whether the Commission expects relays to 

never operate during non-fault conditions. Order No. 733-A discussed an argument made 

 65 See EEI/NRECA Request at 29–30. 

66 Order No. 733-A, 134 FERC ¶ 61,127 at P 22. 

67 See Order No. 693, FERC Stats. & Regs. ¶ 31,242 at P 185. 
Docket No. RM08-13-004 - 20 - 

by EEI that it would be better for relays to trip for certain known but uncommon, nonfault conditions rather than risk not tripping for another condition. As part of its response 

to this argument, the Commission said that “a protection relay, as an integral part of the 

Bulk-Power System, must not operate during non-fault conditions, regardless of how few 

times the relay may actually operate.”68 EEI/NRECA assert this statement suggests the 

Commission wants 100 percent security and seek clarification that the Commission does 

not expect that relays will never operate during non-fault condition.69 

43. Order No. 733-A addressed this matter in the context of stable power swings, 

when the Commission said “we do not direct the development of a Reliability Standard 

containing an absolute obligation to prevent protection relays from operating 

unnecessarily. . . .”70 We clarify that the language identified by EEI/NRECA is the 

design condition expected of such protection relay systems and not an expectation that 

such a design will always achieve its objective 100 percent of the time. In other words, 

we do not expect perfect relay operation. However, the design and implementation of 

relay systems pursuant to Reliability Standard PRC-023 should duly consider the 

appropriate balance between security and dependability as they strive to avoid settings 

that will result in relay operation under non-fault conditions.71 Accordingly, we grant 

clarification of this issue. 

E. Relays Located at Generators 

44. In Order No. 733, the Commission distinguished between two roles for protection 

relays located at the generator terminal on the low-voltage side of a generator step-up 

transformer. Such relays can: (1) provide backup protection for a Bulk-Power System 

element such as a transmission line outside of the generator zone of protection, or 

(2) provide backup protection for the generator and step-up transformer.72 The 

Commission stated that those relays that provide backup protection to transmission lines 

 68 Order No. 733-A, 134 FERC ¶ 61,127 at P 131. 

69 EEI/NRECA Request at 33–34. 

70 Order No. 733-A, 134 FERC ¶ 61,127 at P 107. 

71 Relay dependability and security are not synonymous. The dependability of a 

relay addresses whether the relay will trip during a fault; security addresses whether the 

relay will not trip in the absence of a fault. See Order No. 733-A, 134 FERC ¶ 61,127 at

P 127. 

72 Order No. 733, 130 FERC ¶ 61,221 at P 113. 
Docket No. RM08-13-004 - 21 - 

and transformers are subject to Reliability Standard PRC-023-1.73 In Order No. 733-A, 

the Commission clarified that it does not intend the Reliability Standard to apply to 

backup protective relays connected to current transformers at the neutral end of the 

generator.74 Order No. 733-A also noted that Attachment A to PRC-023-1 explicitly 

excludes generator protection relays that are susceptible to load, but Attachment A does 

not exclude any other type of relay physically located on the low-voltage side of a 

generator step-up transformer.75 Thus, the Commission concluded that, by its very terms, 

the Reliability Standard applies to generator protection relays located at the generator 

step-up transformer.76

45. Order No. 733-A states that Reliability Standard PRC-023-1 applies to relays 

which, though “they may be connected to current transformers located at the generator 

terminal or on the low-voltage side of the generator step-up transformer, are set to 

provide backup protection for Bulk-Power System elements.”77 EEI/NRECA 

characterize this statement as being in conflict with the Commission’s stated expectation 

that “the ERO will develop [a] Reliability Standard addressing generator loadability as a 

new Reliability Standard with its own individual timeline, and not as a revision to an 

existing Standard”78 and request clarification of this apparent conflict. 

46. EEI/NRECA also argue that relays that sense in the direction of the transmission 

system serve to protect the thermal limits of the generating asset rather than loadability of 

the transmission system. Since the generator operates at a lower power capacity than the 

transmission system, EEI/NRECA claim that setting the relay in accordance with 

Reliability Standard PRC-023-1 may not adequately protect the generating asset. 

Moreover, because the relays are applied at the generating terminals and not the 

transmission lines, they do not restrict transmission loadability. Finally, EEI/NRECA 

assert that failure to clarify the scope of PRC-023-1 will change the function of these 

relays from protection of generation assets to supporting transmission loadability. 

 73 See id. P 112. 

74 Order No. 733-A, 134 FERC ¶ 61,127 at P 93. 

75 Id.

76 Id. 

77 Id. P 94 (citation omitted). 

78 Id. P 95, citing Order No. 733, 130 FERC ¶ 61,221 at P 106. 
Docket No. RM08-13-004 - 22 - 

 Commission Determination

47. The orders in this proceeding state that Reliability Standard PRC-023-1 applies to 

relays set to provide primary or backup protection to transmission elements rather than to 

generators.79 We see no conflict between this statement and the stated expectation that 

the ERO will develop a new Reliability Standard addressing generator relay loadability. 

The Commission addressed EEI/NRECA’s perceived conflict in Order No. 733 when it 

stated: 

Our statement that such relays are subject to the Reliability Standard is not 

in conflict with the use of a protection system to protect the generator/stepup transformer in the context of other industry standards, such as IEEE 

Standard C37.102, or with the exclusion in section 3.4 of Attachment A to 

PRC-023-1 of generator relays that are susceptible to load. The relays that 

we referred to in the NOPR, while they may be physically located at the 

generator terminal or on the low-voltage side of the generator step-up 

transformer, are applied to provide backup protection for Bulk-Power 

System elements. This application is different from “generator relays,” 

which are also physically located at the generator, but are applied to protect 

the generator.80

48. Further, we disagree with EEI/NRECA’s broad claim that all relays sensing in the 

direction of the transmission system serve to protect the thermal limits of the generating 

assets and that our assertion as to the scope of PRC-023-1 changes the function of these 

relays from protecting generation assets to supporting transmission loadability. 

Certainly, some relays sensing in the direction of the transmission system are set to 

protect generating assets, but our statement regarding PRC-023-1’s applicability was not 

directed at those relays. Instead, we address only that subset of relays set to provide 

backup protection for Bulk-Power System elements. 

49. While such relays may be few in number, distance relays can be physically located 

at the generator terminal on the low-voltage side of a step-up transformer, sensing in the 

direction of the transmission system, and function as backup protection for a Bulk-Power 

System fault (i.e., for a transmission line outside of the generator zone of protection) in 

case the transmission system relays fail to clear a fault.81 This understanding is 

 79 Id. P 94, 98; Order No. 733, 130 FERC ¶ 61,221 at P 112. 

80 Order No. 733, 130 FERC ¶ 61,221 at P 114 (citation omitted). 

81 Id. P 113. 
Docket No. RM08-13-004 - 23 - 

confirmed in NERC’s Technical Reference Document, Power Plant and Transmission 

System Protection and Coordination, written by industry experts and approved by 

NERC’s Planning Committee. This document states that “[t]he generator impedance 

relay can be set to provide trip dependability for faults on transmission lines when relays 

fail.”82 In such instances, where the relay is set to trip for faults on transmission lines, 

the relay must be coordinated with generator protection devices, but the relay is designed

to trip the step-up transformer and generator in order to stop current flowing from th

generator to the faulted line when transmission line relays fail.

e 

 

83

50. Because relays can be set to trip for faults on transmission lines, they can restrict 

transmission loadability notwithstanding that they are applied at the generator rather than 

on the transmission system. If the relay can inappropriately trip the step-up transformer 

and generator under non-fault conditions, it can leave other generators to shoulder its 

share of the system load. 

51. EEI/NRECA assert that, because a generator operates at a lower power capacity 

than the transmission facility to which it is connected, setting a relay in accordance with 

Reliability Standard PRC-023-1 may not adequately protect the generating asset. This 

assertion appears to be contradicted by the above-quoted statement in the NERC 

Technical Reference Document, but it does not conflict with the Commission’s 

statements in Order No. 733 and Order No. 733-A. The Commission has not stated that a 

relay whose function is to protect the generating asset is subject to PRC-023-1. In Order 

No. 733, the Commission declined to extend the Reliability Standard to generator step-up 

and auxiliary transformer loadability, agreeing with the ERO that the matter could 

appropriately be addressed in a separate Reliability Standard.84 In the context 

contemplated by EEI/NRECA’s argument, where the relay is set to protect generating 

elements, the relay may be set in whatever manner is appropriate to achieve its intended 

purpose. 

82 North American Electric Reliability Corp., Technical Reference Document, 

Power Plant and Transmission System Protection Coordination 34 (2009). The 

Reference Document then continues to describe the technical details on how the 

generator impendence relay should be set to provide trip dependability for faults on 

transmission lines. 

83 See id. at 35. 

84 Order No. 733, 130 FERC ¶ 61,221 at P 104; see also Order No. 733-A, 

134 FERC ¶ 61,127 at P 98. 
Docket No. RM08-13-004 - 24 - 

52. Accordingly, we deny the EEI/NRECA request for clarification of the 

Commission’s statements regarding the applicability of Reliability Standard PRC-023-1 

to relays located at a generator terminal that serve to protect Bulk-Power System 

elements. 

F. Untimely Arguments

53. The Trade Associations assert the Commission’s directives regarding (a) creation 

of a uniform test to identify critical sub-200 kV facilities, (b) subjecting supervisory 

relays to PRC-023-1, and (c) creation of a new Reliability Standard addressing protective 

relays that can differentiate between stable power swings and faults are based on errors of 

fact. These directives, they assert, reflect a misunderstanding of protection system 

engineering and of the Blackout Report. EEI/NRECA argue that, to the extent the 

Commission failed to consider the negative reliability implications of the directives, 

reached conclusions contrary to the findings or recommendations of the Blackout Report, 

or exceeded a mere difference of opinion regarding the directives’ engineering 

implications, the directives are arbitrary and capricious. 

54. While Order No. 733-A offered clarifications of the Commission’s earlier 

directives regarding creating a uniform test to identify critical sub-200 kV facilities and 

subjecting supervisory relays to PRC-023-1, the arguments raised in the Trade 

Associations’ motions do not arise as a result of new information set forth in our 

clarifications. Instead, they attempt to revisit the technical basis for the Commission’s 

directives. The Trade Associations should have raised these arguments in response to the 

NOPR. Failing that, the arguments should have been raised on rehearing prior to the 

issuance of Order No. 733-A. 

55. The Commission does not allow rehearing of an order denying rehearing.85 Any 

other result would lead to never-ending litigation as every response by the Commission to 

a party’s arguments would allow yet another opportunity for rehearing unless presumably 

that response were word-for-word identical to what the Commission earlier said.86 

 85 See, e.g., Bridgeport Energy, LLC, 114 FERC ¶ 61,265 (2006) (Bridgeport); 

Cargill Power Markets, LLC et al., 114 FERC ¶ 61,093 (2006); Southern Company 

Services, Inc., 111 FERC ¶ 61,329 (2005); AES Warrior Run, Inc. v. Potomac Edison 

Company d/b/a Allegheny Power, 106 FERC ¶ 61,181 (2004); Southwestern Public 

Service Co., 65 FERC ¶ 61,088, at 61,533 (1993). 

86 See, e.g., Bridgeport, 114 FERC ¶ 61,265 at P 8, citing Canadian Association of 

Petroleum Producers v. FERC, 254 F.3d 289, 296 (D.C. Cir. 2001) (rejecting the notion 

of “infinite regress” that would “serve no useful end”). 
Docket No. RM08-13-004 - 25 - 

Litigation before the Commission cannot be allowed to drag on indefinitely – at some 

point it must end – and so the Commission does not allow parties to seek rehearing of an 

order denying rehearing. As the U.S. Court of Appeals for the District of Columbia 

Circuit has explained, even “an improved rationale” does not justify a further request for 

rehearing.87

56. Matters that do not arise as a result of a modification of Order No. 733 by Order 

No. 733-A should have been raised previously in a motion for rehearing of Order No. 733 

and are therefore rejected based on the procedural defect. 

57. Further, in support of their arguments, EEI/NRECA append to their motion two 

affidavits of Thomas E. Wiedman (Wiedman Affidavit) and William J. Miller (Miller 

Affidavit) addressing the Blackout Report and various engineering matters such as the 

role and function of supervisory relays. These issues were first addressed in the NOPR 

and should have been raised in comments to it.88 These issues were also addressed in the 

Order No. 73389 and again in Order No. 733-A.90 The Commission looks with disfavor 

on parties raising issues for the first time on rehearing because other parties are not 

permitted to respond to a request for rehearing.91 The introduction of such material is 

“disruptive to the administrative process because it has the effect of moving the target for 

parties seeking a final administrative decision.”92 The Trade Associations should have 

raised these concerns in comments to the NOPR or on rehearing of Order No. 733 and do 

 87 Southern Natural Gas Co. v. FERC, 877 F.2d 1066, 1073 (D.C. Cir. 1989) 

(Southern) (citing Tennessee Gas Pipeline Co. v. FERC, 871 F.2d 1099, 1109-10 (D.C. 

Cir. 1989)); see also Londonderry Neighborhood Coalition v. FERC, 273 F.3d 416, 423-

24 (1st Cir. 2001). 

88 E.g., NOPR, FERC Stats. & Regs. ¶ 32,642 at P 11, 30–45, 54–60, 78–80. 

89 E.g., Order No. 733, 130 FERC ¶ 61,221 at P 47–97, 150–173, 250-272. 

90 E.g., Order No. 733-A, 134 FERC ¶ 61,127 at P 14–17, 22, 30-39, 48–65, 104–

113, 129–134. 

91 Westar Energy, Inc., 134 FERC ¶ 61,176, at P 23 (2011), citing Calpine Oneta 

Power v. American Elec. Power Serv. Corp., 114 FERC ¶ 61,030 (2006); Midwest Indep. 

Transmission Sys. Op., Inc., 112 FERC ¶ 61,211, at P 34 (2005) (citing Baltimore Gas & 

Elec. Co., 91 FERC ¶ 61,270 (2000) and Baltimore Gas & Elec. Co., 92 FERC ¶ 61,043, 

at 61,114 (2000)). 

92 Midwest Indep. Transmission Sys. Op., Inc., 112 FERC ¶ 61,211 at P 34. 
Docket No. RM08-13-004 - 26 - 

not explain why they failed to provide the material contained in the affidavits at an earlier 

stage in this proceeding. Therefore, we reject the affidavits and disregard all citations to 

extra-record evidence. 

58. While we reject the untimely arguments and affidavits on procedural grounds, we 

nonetheless review these matters and, in the alternative, deny the requests on substantive 

grounds. Accordingly, below, we review in summary fashion the following issues denied 

as untimely requests for rehearing that are raised either in the EEI/NRECA Request or in 

the supporting affidavits: (1) identification of critical sub-200 kV transmission facilities; 

(2) supervisory relays; (3) due weight owed to the ERO’s recommendation; and (4) stable 

power swings. While some arguments regarding the weight owed to the ERO’s 

recommendations were timely raised and are discussed above, the arguments addressed 

below are rejected as procedurally defective since they do not arise out of a clarification 

made in Order No. 733-A. Similarly, though we have already addressed stable power 

swings above, we return to that subject to address matters raised out-of-time in the 

Wiedman Affidavit. 

1. Identification of Critical Sub-200 kV Transmission Facilities

 EEI/NRECA Arguments

59. EEI/NRECA argue that the Commission’s directive to create a uniform test to 

identify critical sub-200 kV facilities is not supported by the Blackout Report. In 

particular, EEI/NRECA, relying on the Wiedman affidavit, question the accuracy of the 

Order No. 733-A statement that critical facilities between 100 and 200 kV must be 

identified and subject to PRC-023 “to prevent a recurrence of the undesirable system 

performance that occurred during the August 2003 blackout.”93 While Order No. 733-A 

refers to the tripping of thirteen lines during a four minute period, EEI/NRECA argue the 

tripping of the 138 kV lines would have happened regardless of whether they were 

subject to the loadability requirements of PRC-023-1.94 

60. EEI/NRECA rely on the Wiedman affidavit’s statements that the Blackout Report 

indicates that the steady state loadability of transmission relays at 345 kV were at issue. 

Mr. Wiedman avers that, since PRC-023 protects the loadability of the 345 kV lines, the 

138 kV lines tripped due to system conditions directly related to the 345 kV line trips in 

the immediate vicinity.95 Wiedman posits that, if the 345 kV lines did not trip (because 

 93 EEI/NRECA at 7; Wiedman Affidavit P 42. 

94 EEI/NRECA at 7-8. 

95 Wiedman Affidavit P 9. 
Docket No. RM08-13-004 - 27 - 

the relays were properly set pursuant to PRC-023), the control room operators at 

FirstEnergy would have had sufficient time to manually shed load and arrest a potential 

cascade.96 Thus, according to the affidavit, inclusion of the 138 kV facilities in PRC-023 

would not have improved performance during the 2003 blackout. 

Commission Determination

61. We are unpersuaded by EEI/NRECA’s reasoning. First, while NERC’s 

predecessor organization, the North American Electric Reliability Council, recommended 

that transmission owners evaluate the settings of zone 3 relays on all transmission lines of 

230 kV and higher, it was the U.S. – Canada Task Force, with technical advice from the 

Electric System Working Group,97 that recommended that the review be broadened to 

include operationally significant 115 kV and 138 kV lines.98 Moreover, NERC, utilizing 

industry experts in the standards drafting process, developed Reliability Standard PRC023-1, which requires planning coordinators to determine which 100-200 kV facilities are 

critical to the reliability of the bulk electric system in order to identify facilities to be 

subject to the Standard. The Commission directive pertained to the development of a 

uniform test for planning coordinators to apply when identifying such facilities. 

62. Second, EEI/NRECA assert that the basis for the directive to develop a uniform 

test is found in a flawed analysis of the events of the August 2003 Blackout, quoting Mr. 

Wiedman’s assertion that “[t]he inclusion of sub-200 kV facilities in the PRC-023 would 

not have improved performance during the August 2003 Blackout.”99 But Order 

No. 733-A explained that the 138 kV lines at issue did not trip as a result of the matters 

addressed by Reliability Standard PRC-023-1.100 Rather than the specific role played by 

 96 Wiedman Affidavit P 49. 

97 See generally Blackout Report, Appendix A, Members of the U.S.-Canada 

Power System Outage Task Force and its Three Working Groups, (composition of Task 

Force and the Electric System Working Group), and Appendix B, Description of Outage 

Investigation and Process for Development of Recommendations, at 175-187. 

98 Blackout Report at 156. 

99 EEI/NRECA Request at 8. 

100 Order No. 733-A, 134 FERC ¶ 61,127 at P 35 citing Order No. 733, 130 FERC 

¶ 61,221 at P 52 (“The cascade of 138 kV lines was precipitated by faults caused by tree 

contact, not protective relays, and would not have been prevented if PRC-023-1 had been 

in effect before the blackout.”). 
Docket No. RM08-13-004 - 28 - 

relays on sub-200 kV facilities during the August 2003 Blackout, the Commission’s 

concern was the inclusiveness of the test.101 After its examination of the August 2003 

Blackout, the U.S. – Canada Task Force determined that zone 3 relays on operationally 

significant 100-200 kV circuits should be evaluated because they were one of the causes 

for a portion of the blackout. The Task Force adopted a methodical approach addressing 

each of the factors that played a role in a blackout since in order to achieve the reliability 

goal, all the causes must be addressed. 

63. Accordingly, were these issues timely raised and not barred from consideration, 

we would nevertheless deny EEI/NRECA’s request for clarification regarding the 

directive to develop a uniform test to identify critical sub-200 kV facilities. 

 2. Supervisory Relays 

 EEI/NRECA Arguments

64. EEI/NRECA argue that the overbroad nature of the Commission’s directive on 

supervisory relays is based on an incorrect characterization of relay engineering and 

would likely lead to a reduction in reliability. Adding supervisory relays to the scope of 

the Standard, they contend, would add costs while threatening to harm reliability. The 

Miller Affidavit purports to survey supervisory relays applied for both voltage and 

current supervision on a variety of protection systems in normal operation and, in one 

instance, during protection system failures. Mr. Miller, however, states that experienced 

engineers generally agree with applying Reliability Standard PRC-023 to phase 

overcurrent supervisory elements associated with current-based communication-assisted 

schemes where the scheme is capable of tripping for a loss of communication.102 

Commission Determination

65. We do not dispute the observations concerning many technical applications raised 

in the Miller Affidavit. The Commission’s reliability concern arises from an actual 

incident, and the Miller Affidavit supports application of PRC-023 to the protection 

scheme involved in that event. As a result of that incident, we concluded that it is 

inappropriate to exclude all supervising relays from the scope of PRC-023. The concern 

EEI/NRECA raises about our directive regarding supervising relays should be 

ameliorated by our clarification made above that the directive does not foreclose the 

 101 Order No. 733-A, 134 FERC ¶ 61,127 at P 22 (citing Order No. 733, 

130 FERC ¶ 61,221 at P 49-50, 77-78). 

102 Miller Affidavit at 8. 
Docket No. RM08-13-004 - 29 - 

development of a tailored approach that applies the Standard to some supervising relays 

but not to others. 

3. Due Weight Owed to the ERO’s Recommendation Regarding 

Implementation of Blackout Report’s Recommendations 

 EEI/NRECA Arguments

66. EEI/NRECA contend that the Commission’s directives regarding PRC-023-1 are 

not supported by the Blackout Report, but the proposed Reliability Standard does satisfy 

the Blackout Report’s recommendations. They argue that, had proposed Reliability 

Standard PRC-023-1 been properly implemented prior to August 2003, the 345 kV 

Sammis-Star line would not have tripped and the control room operators at FirstEnergy 

should then have had enough time to manually shed load thus averting the cascade. 

EEI/NRECA further argue that proposed Reliability Standard PRC-023-1 is therefore an 

appropriate exercise of NERC’s technical expertise and deserves deference. 

Commission Determination

67. The Commission does not share the same confidence that PRC-023-1, properly 

implemented, would have allowed system operators to prevent the cascade that followed 

the tripping of the Sammis-Star line. In filing Reliability Standard PRC-023-1 for 

Commission approval, the ERO was only prepared to say: 

[i]t is difficult to be certain about the effects that this proposed reliability 

standard would have had on the end-state of the blackout. Considered in 

concert with other activities that have been precipitated by the blackout 

investigation, it seems clear that the events of the blackout would have 

taken a very different course and that relay loadability would not have been 

as pivotal a factor as seen on August 14, 2003.103 

Similarly, Order No. 733-A states that “[t]o assert, as Order No. 733 does, that one 

cannot definitely conclude on the present record that PRC-023-1 would have 

prevented the spread of the blackout...by no means is intended to minimize the 

significance of relay loadability.”104 

 103 NERC, Petition for of PRC-023-1 Reliability Standard, Docket No. RM08-13-

000, at 7 (filed July 30, 2008). 

104 Order No. 733-A, 134 FERC ¶ 61,127 at P 38 (citation omitted). 
Docket No. RM08-13-004 - 30 - 

68. Nevertheless, even if one were to assume the accuracy of EEI/NRECA’s claim 

regarding PRC-023-1, it would not foreclose the Commission from making directives 

with respect to the subject matter of the Reliability Standard. The standard for review of 

proposed Reliability Standards or modifications to existing Standards is not, as presented 

by EEI/NRECA, an inquiry into whether they are “needed to prevent the re-occurrence of 

events such as those that occurred during the August 2003 [b]lackout.”105 A directive is 

authorized under section 215(d)(5) if it is appropriate to carry out the purposes of section 

215 of the FPA. Thus, while the technical expertise of the ERO must be given due 

weight, the fact that compliance with a proposed Reliability Standard would have 

mitigated the August 2003 Blackout does not prevent the Commission making directives 

to address identified gaps in reliability associated with the Standard. 

69. Accordingly, were this issue timely raised and not barred from consideration, we 

would nevertheless deny EEI/NRECA’s request for clarification regarding whether the 

Commission properly gave due weight to the ERO’s technical expertise. 

 4. Stable Power Swings

Wiedman Affidavit

70. In his affidavit, Mr. Wiedman argues the tripping of lines that occurred during the 

August 2003 Blackout was not the result of the inability of relays to distinguish between 

faults and stable power swings but rather was the result of loading conditions on extra 

high-voltage power lines. During the time after the Sammis-Star line tripped and the 

system separated, the Blackout-Report does not refer to any line trip as the result of either 

a stable or an unstable power swing. Furthermore, he argues, the Commission’s directive 

does not sufficiently reflect the threat to reliability posed by the modification of existing 

relay settings. 

Commission Determination

71. We agree with Mr. Wiedman that the Blackout Report does not identify lines as 

tripping because of stable or unstable power swings during the period between the 

Sammis-Star tripping and the system separating, nor does the report identify steady state 

current flows as the cause of relays tripping. His affidavit simply fails to address how it 

came to be that zone 3 relays tripped without stable power swings. He asserts that the 

Galion-Ohio Central-Muskingum 345 kV line tripped by its zone 3 relay because of a 

load current that was well above its emergency line conductor rating, and that several 138 

kV lines tripped, mostly by zone 3 or zone 2 impedance relays, as they experienced levels 

 105 EEI/NRECA Request at 19. 
Docket No. RM08-13-004 - 31 - 

of line overload.106 But he fails to address how, absent a stable or unstable power swing, 

the line current rose to the point that the impedance encroached those zone 3 relays’ 

operating zones. 

72. Mr. Wiedman’s assertion that the zone 3 relay on the Sammis-Star line tripped 

when experiencing a voltage of 95 percent of normal and a current just barely above its 

thermal rating is troubling. Such conditions are essentially within normal operation, and 

tripping would only occur if the impedance, as seen by the zone 3 relays, encroached into 

the operating zone of the relay. Stable power swings can cause relays to unreliably detect 

fault conditions. Mr. Wiedman does not deny this; he only argues the Blackout Report 

does not explicitly state stable power swings were the cause of any given line tripping 

while failing to acknowledge the Report’s statements about the impact of power 

swings.107 The ERO and the Blackout Report confirm the threat posed by stable power 

swings to system reliability.108 We are unpersuaded by Mr. Wiedman’s arguments. 

73. As for Mr. Wiedman’s assertion that the Commission’s directive regarding stable 

power swings downplays the threat to reliability posed by the modification of existing 

relay settings, we note that the examples he gives would fail to meet the Reliability 

Standard PRC-001’s requirement that protective systems be coordinated. There are 

alternative approaches to addressing our directive that Mr. Wiedman does not mention. 

We are therefore not convinced that the ERO’s response to our directive will result in a 

diminution of reliability. Accordingly, were these issues timely raised and not barred 

from consideration, we would nevertheless deny EEI/NRECA’s request for clarification 

regarding stable power swings. 

 106 Wiedman Affidavit at 1-11. 

107 E.g., Blackout Report at 73 (“Power swings and voltage fluctuations caused by 

[a few initiating events as seen on August 14, 2003,] can cause other lines to detect high 

currents and low voltages that appear to be faults, even if faults do not actually exist on 

those other lines.”); Blackout Report at 80 (“The Sammis-Star line tripped at 16:05:57 

EDT on a zone 3 impedance relay although there were no faults occurring at the time, 

because increased real and reactive power flow caused the apparent impedance to be 

within the impedance circle (reach) of the relay.”). 

108 See Section II.B. Stable Power Swings, supra. In addition, in its 

Informational Filing, the ERO states that it has unpublished analysis that show some of 

the lines that tripped during the August 2003 Blackout were due to stable power swings. 

NERC Informational Filing at 6-7. 
Docket No. RM08-13-004 - 32 - 

The Commission orders:

 (A) The requests for clarification are hereby granted, in part, and denied, in 

part, as discussed in the body of this order. 

 (B) The requests for reconsideration are hereby denied. 

By the Commission. 

( S E A L ) 

Nathaniel J. Davis, Sr., 

Deputy Secretary.