Recent RUS Publications

Fred Gatchell, Deputy Director, Electric Staff Division, RUS

Updated February, 2000

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RUS Technical Publications

RUS has issued a number of technical publications recently. These publications include:

RULES:

• 7 CFR 1710, Subpart E, “Load Forecasts and Market Analysis.” This proposed rule,

published July 7, 1999, will change the existing load forecasting regulations. The

proposed changes are intended to reduce the overall administrative burden of reporting

load forecasts to RUS. The proposed changes will also allow RUS to accept less detailed

analysis for smaller borrowers. Public comments have been reviewed and addressed, and

the final rule should be published shortly. For more details, see the paper entitled “Load

Forecasting in a Competitive Environment,” or call Georg Shultz of the Electric Staff

Division (ESD) at (202) 720-1920.

• 7 CFR 1721, “Post-Loan Policies and Procedures for Insured Electric Loans.” This

direct final rule, published December 28, 1999, changes the existing regulations

concerning advance of funds. Specifically, we have changed the rules as follows:

∗ The threshold limit for a “minor project” has been increased from $25,000 to

$100,000, and

∗ The limitation of RUS funding to 130% of the project cost estimate without prior

RUS approval has been eliminated.

A minor project can be funded from an RUS loan even though it was not included in the

approved loan, Construction Work Plan (CWP), or CWP amendment. By increasing the

threshold limit for a minor project to $100,000, borrowers will have more flexibility to use

their RUS loan funds for priority projects that were not anticipated at the time of the loan

or CWP. A minor project must be consistent with the purposes permitted by the loan

contract, and total advances cannot exceed the total loan amount.

RUS implemented the “130% rule” in 1985 to improve control over use of RUS loan

funds. In recent years, the majority of cases of noncompliance with this rule relate to

distribution line extensions and miscellaneous equipment needed to serve new consumers.

Since borrowers have little or no control over how many new customers will need to be

connected and have no choice but to connect them, RUS approval to exceed 130% of the

original estimate for this type of work is superfluous. For other major projects, borrowers

have been providing good cost estimates unless the project has been changed significantly,

in which case borrowers generally submit a CWP amendment for RUS approval. Since

total advances still cannot exceed the total loan amount, we have determined that the
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130% rule is no longer needed and that the associated administrative burden on the

borrowers can be eliminated.

Since no adverse comments were received, this direct final rule became effective on

February 11, 2000. For more information about this action, please call Charles Philpott of

the Northern Regional Division at (202) 720-1432.

• Bulletin 1728F-806, “Specifications & Drawings for Underground Electric

Distribution” (incorporated by reference). The proposed rule covering the revision of

this bulletin was published on April 8, 1998. This is an update of an existing bulletin,

which was known as Bulletin 50-6.

This bulletin provides the specifications and drawings that are used in the construction of

underground distribution facilities. It is one of the RUS standards that help borrowers

build safe, reliable, and economical electric facilities in rural America.

We have made a number of changes to this bulletin, including the addition of two new

drawings (UC-1 and UC-2) which provide alternative construction arrangements for the

interface between overhead and underground facilities. We have also deleted 23 drawings

and the URD Inspection Form, which are obsolete and no longer needed.

We have also incorporated a number of design changes in the drawings, including some

that were recommended by the Underground Subcommittee of the NRECA T & D

Committee and some suggestions that we received through the public comment process.

We have also revised some of the clearances to conform to the latest code requirements.

We have updated the references to the referenced codes, specifications and standards to

reflect the latest editions of these documents. Changes to a number of drawings showing

caution, warning, and danger signs were needed to reflect the latest codes and standards

concerning signs. Finally, we have revised or redrawn a number of drawings for greater

clarity and ease of use.

Public comments have been reviewed and addressed, and publication of the final rule is

expected shortly. For more information about this action, please call Trung Hiu of ESD at

(202) 720-1877.

• 7 CFR Part 1792, Subpart C, “Seismic Safety of Federally Assisted New Building

Construction.” RUS is revising its existing regulations concerning seismic safety. The

proposed revision would update and simplify the seismic safety requirements for new

building construction using RUS or Rural Telephone Bank (RTB) loan, grant, or

guaranteed funds or funds provided through lien accommodations or subordinations

approved by RUS or RTB.

The Earthquake Hazards Reduction Act of 1977 and its associated Executive Order

require that federally assisted new building construction meet certain seismic safety

standards. These requirements are intended to reduce risk of loss of life and property

damage caused by earthquakes. The Interagency Committee on Seismic Safety in
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Construction and the National Earthquake Hazards Reduction Program (NEHRP) have

been created to coordinate these efforts. 7 CFR Part 1792, Subpart C, which was

originally issued in 1993, implements these requirements for RUS.

The proposed revision changes the list of acceptable model codes and standards that new

buildings need to conform to in order to meet seismic provisions. In order for a model

building code to be acceptable, the code must contain requirements equivalent to the 1994

NEHRP Recommended Provisions. The 1997 ICBO Uniform Building Code (UBC) and

ASCE 7-95, Minimum Design Loads for Buildings and Other Structures, have been found

to be acceptable for seismic safety purposes.

The proposed revision also eliminates the post-construction seismic certification and

simplifies the requirements concerning the acknowledgement that the seismic safety

provisions of the applicable model code are incorporated in the design of the building.

For more information about this action, please call Don Heald at (202) 720-9102.

GUIDANCE DOCUMENTS:

• Bulletin 1724D-112, “The Application of Shunt Capacitors to the Rural Electric

System.” This bulletin examines the application of shunt capacitors on rural distribution

systems and serves as a general guide for capacitor applications to RUS borrowers and

others. The System Planning Subcommittee of NRECA’s T&D Committee has been

instrumental in the development of this bulletin. This is an update of an existing bulletin,

which was known as Bulletin 169-1. Publication of this bulletin is expected shortly.

As a rural power distribution system load grows, the system power factor usually declines.

This gradual load growth and decrease in power factor increases system energy losses,

lowers voltages at consumers' premises, degrades the performance of energy utilization

equipment, and drives up the cost per unit of energy delivered. For optimum performance

and avoidance of these undesirable conditions, especially in today’s competitive electric

industry, prudent utility providers need to make every effort to maintain power factor as

close to 1.0 as economically practical. Chapter 1 recognizes the importance of power

factor correction and discusses these conditions warranting power factor correction in

detail.

Chapter 2 provides a discussion of how capacitors work, including a power factor

definition and description of power triangle relationships. Power factor effects on the

power triangle relationships are explained. Load factor effects on power factor and

capacitor sizing are introduced. The chapter ends with further discussion of voltage

improvement through the use of capacitors.

Issues of particular concern in capacitor use are the topic of Chapter 3. These issues

include overcurrent and overvoltage protection, and harmonic disturbances. Capacitor

performance standards and capacitor failure/disposal are discussed. Four solutions for

problems involving harmonics are offered for consideration.
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Chapter 4 covers the sizing, siting, and use of capacitors on rural electric systems. These

topics include many areas of interest to the distribution planning engineer. Within the

context of these topic headings, subjects such as light and peak loading, three phase banks,

automatic capacitor switching, fusing, and safety precautions are discussed. The current

RUS standard three-phase capacitor drawing is also included.

The final two chapters consider power supply effects of capacitor use (Chapter 5) and

capacitor use with induction motors (Chapter 6). Power supply considerations include

effects on substations and transmission lines. The discussion of capacitor use and

induction motors covers such topics as switched capacitor banks, secondary capacitors,

and series primary capacitors.

For further information about this bulletin, please call Chris Tuttle at (202) 205-3655.

• Bulletin 1724E-104, “Reduced Size Neutral Conductors for Overhead Rural

Distribution Lines,” dated 9/23/99. This bulletin covers the principal considerations

applicable to reduced size neutral conductors and outlines a procedure for their selection

and installation. This is an update of an existing bulletin, which was known as

Bulletin 61-4.

While the use of reduced size neutral conductors can result in significant savings in

distribution line construction, there are a number of important considerations that must be

addressed. The considerations covered in this bulletin include:

∗ Neutral load current

∗ Fault currents, both high and low

∗ Harmonics

∗ Minimum conductivity

∗ Economics

∗ Mechanical properties

∗ Large phase conductor characteristics

The bulletin includes suggested procedures for the selection of neutral conductor size

under various loading scenarios. It also provides guidance concerning line staking and

conductor sagging when using reduced size neutral conductors.

Tables of the more common conductor combinations used in RUS standard construction

are also included in the bulletin.

For more information about this bulletin, please call Jim Bohlk of ESD at (202) 720-1967.

• Bulletin 1726C-115, “Checking Sag in a Conductor by the Return Wave Method,”

dated September 24, 1998. This bulletin presents a convenient and practical method for
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checking sag in a conductor regardless of span length, tension, size, or type of conductor.

This is an update of an existing bulletin, which was once known as Bulletin 80-4.

This bulletin is based on the fact that for a conductor suspended in air between two fixed

supports, the time required for a wave to travel between those supports is dependent on

the conductor sag. The bulletin includes the mathematical formula used to determine

conductor sag as well as tables derived from that formula. Procedures to be used for

initiating a wave and for determining the elapsed time for the wave to travel between the

supports are also included.

For more information about this bulletin, please call Stephen Jones of ESD at

(202) 720-1792.

• Bulletin 1728F-800, “Assembly Unit Numbers and Standard Format,” dated

December 16, 1998. This bulletin explains and documents the RUS construction unit

numbering scheme and the new numbering format used in new and revised RUS

construction drawings. For more details, see the paper entitled “Overhead Distribution

Line Specifications,” or call Jim Bohlk of ESD at (202) 720-1967.

• The Summary of Items of Engineering Interest, published in July 1999, continues the

practice of furnishing annually, on an informal basis, engineering information and

developments related to the rural electrification program.

• IP 202-1, “List of Materials Acceptable for Use on Systems of RUS Electrification

Borrowers,” published in July 1999, and its quarterly supplements. This document

provides a convenient listing of the materials and equipment that have been accepted by

RUS.

If you need any of these publications, please contact RUS' Program Development and Regulatory

Analysis staff at (202) 720-8674. Many RUS publications are also available via the Internet at:

For Rules: http://www.usda.gov/rus/electric/regs.htm

For Bulletins: http://www.usda.gov/rus/electric/bulletins.htm
BIOGRAPHICAL SKETCH

FRED J. GATCHELL

Mr. Gatchell is the Deputy Director of the Electric Staff Division, responsible for, among other

duties, coordinating the updating and issuing of many of RUS’ technical publications. In his

26 years with RUS/REA, he has also been with the Power Engineering Branches of the

Northwest and the Northeast Areas and with the Power Plants Branch.

Before joining RUS/REA, Mr. Gatchell worked at the Norfolk Naval Shipyard and at Bechtel

Power Corporation. He received a B.S. in Mechanical Engineering from the University of

Maryland, and is a registered professional engineer in Virginia.
RUS TECHNICAL

PUBLICATIONS

7 CFR 1710, SUBPART E

LOAD FORECASTS AND

MARKET ANALYSIS

RUS TECHNICAL

PUBLICATIONS

7 CFR 1721

POST LOAN POLICIES

AND PROCEDURES
RUS TECHNICAL

PUBLICATIONS

7 CFR 1721 - POST LOAN

POLICIES & PROCEDURES

◆ Minor Project - Up to $100,000

◆ 130% Rule - Eliminated

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1728F-806

UNDERGROUND

DISTRIBUTION

(Incorporated by Reference)
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1728F-806

UNDERGROUND DISTRIBUTION

◆Updates Bulletin 50-6

◆One of the RUS Standards

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1728F-806

UNDERGROUND DISTRIBUTION

◆Two new Drawings -

 Overhead to Underground

◆Eliminated 23 Drawings
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1728F-806

UNDERGROUND DISTRIBUTION

◆Design Changes

◆Update and Clarify

RUS TECHNICAL

PUBLICATIONS

7 CFR 1792, SUBPART C

SEISMIC SAFETY
RUS TECHNICAL

PUBLICATIONS

SEISMIC SAFETY

◆Earthquake Hazards Reduction Act of 1977

◆Interagency Committee on Seismic Safety

◆National Earthquake Hazards Reduction

 Program

RUS TECHNICAL

PUBLICATIONS

SEISMIC SAFETY

MODEL CODES

◆ 1997 UBC

◆ ASCE 7 - 95
RUS TECHNICAL

PUBLICATIONS

SEISMIC SAFETY

◆ Post-Construction Certification Eliminated

◆ Design Acknowledgement Simplified

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724D-112

SHUNT CAPACITORS
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724D-112

SHUNT CAPACITORS

1. Power Factor

2. Capacitors & Power Factor

3. Concerns with Capacitors

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724D-112

SHUNT CAPACITORS

4. Sizing, Siting, & Use

5. Power Supply Effects

6. Induction Motors
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-104

REDUCED SIZE

NEUTRAL CONDUCTORS

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-104

REDUCED NEUTRALS

◆ Neutral Load Current

◆ Fault Currents

◆ Harmonics

◆ Minimum Conductivity
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-104

REDUCED NEUTRALS

◆ Economics

◆ Mechanical Properties

◆ Large Phase Conductor

 Characteristics

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1726C-115

CONDUCTOR SAG BY THE

RETURN WAVE METHOD
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1728F-800

ASSEMBLY UNIT NUMBERS

 AND STANDARD FORMAT

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-216

GUIDE SPECIFICATION FOR

UNGUYED STANDARD CLASS

CONCRETE POLES
RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-216

USE FOR STANDARD

APPLICATIONS

RUS TECHNICAL

PUBLICATIONS

BULLETIN 1724E-216

FOR COMPLEX APPLICATIONS,

USE BULLETIN 1724E-206