Reprinted, with permission, from IEEE Paper A 79 428-4, PES Summer Meeting, Vancouver, 1979

Significance:

Part 2 Development of standards – Reality checks

Progress report to the IEEE PES community on the development of what became IEEE Std 587-1980.

Explains the proposition that a Ring Wave should be added to the traditional unidirectional impulses

NOTE Parallel presentation of the subject made to the European EMC community under the title “A Guideline on

Surge Voltages in AC Power circuits rated up to 600 V”

Filename: Guideline IEEE
THE DEVELOPMENT OF A GUIDELINE 

ON SURGE VOLTAGES IN LOW-VOLTAGE AC POWER CIRCUITS 

F.D. Martzloff, Member, IEEE 

Genera! Electric Company 

Schenectady, N.Y. 12345 

Abstract - Surge voltages In ac power circu~ts become more significant through an application guide that will be prepared in the fut

with the increased application of miniaturized electronics in consumer standard tests wi!! provide a realistic e~.aluation of the surg

and industrial products. A Workmg Group of iEEE is preparing a capability of equipment connected to these power c~r

Guideline describing the nature of these surges in ac power circuits up necessity, the complex real sltuation must be simphfied to 

to 600 V. manageable set of standards. One must recognize the u

The paper describes the data base and approach used by the arbitrary character of any standard and be prepared to 

Working Group and the recommendations proposed to represent typical imperfect approach which can simplify matters, rather than 

surges, in order to obtain feedback before the final writing of the perfect but unattainable match between the actual sltuati

Guideline. standard. 

Two waveforms are proposed, one oscillatory, the other 

unidirectional, depending on the locat~on within the power system. 

Recommendations for source impedance or short-circuit current are THE ORIGIN OF SURGE VOLTAGES 

also included. Surge voltages occurring in low-voltage ac pow

INTRODUCTION originate from two major sources: load switching transients 

or indirect lightning effects on the power system. Load 

transients can be further div~ded into translents assoc~a

Surge voltages occurring in ac power circuits can be the cause major system swiirhirlg such as 

of misoperation or product failure for residential as well as industrial switching; (2) minor switching near the point of Interest: 

systems. The prob!e- has received increaed attention in recent yeais appliance turnoff in a household or the turnoff of other 

because miniaturized solid state devices are more sensitive to voltage individual system; (3) circuiis d,,ociared wlrh 

surges ispikes and transients) than were their predecessors. 

and energy content are less well known. On the basis of measure- effects have been made to yield data on what levels can be 

merits, statistics, and theoretical considerations, a practical if the exact mechanism of any particular surge Is unk

for outlining the environment for use in predicting extreme wave- major mechanisms by which lightning produces surge volta

shapes and energy content can nevertheless be established. A Working 

'Group of the Surge Protective Devices Committee is currently (a) A direct lightning strike to a primary circuit inject

developing such a guideline; this paper reports the status of the currents into the prlmary clrcult, producing voltag

Guideline, presents the considerations whlch led to the approach e~ther ilowing through ground resistance or fl

chosen, and prov~des a possible veh~cle for discussion before the final through the surge Impedance of the prlmary conduc

writing and pubhcation of the Guideline. (b) A lightning strike that misses the line but hits a n

SCOPE object sets up electromagnetic fields which can i

voirages on the conductors of the primary circuit. 

The Q~ideline primarily addresses ac power circuits with rated id The rapid coiiapse of voltage that occurs when a pr

voltages up to 600 V, although some of the conclus~ons offered could arrester operates to limit the prmary voltage co

appiy to higher voltages and also to some dc power systems. Other effectively through the capdcitance of the transf

standards have been established, such as iEEE 472, Guide for Surge and produces surge voltages in addit~on to those co

Withstand Capability (SWC) Tests, intended for the special case of lnto the secondary circuit by normal transformer ac

hlgh-voltage substation environments, and IEEE 28, Standard for Surge 

Arresters for ac Power Circuits, covering primarily the utilities en- (d) Lightning strikes the secondary circuits directly. 

vironment. The Guideline intends to complement, not conflict with, high currents can be ~nvolved, exceeding the capa

exist~ng standards. ot conventional devices. 

The surge voltages considered in the Guideiine are those (e) Lightning ground current flow resulting from n

exceeding two per unit (or twice the peak operating voltage) and direct-to-ground discharges couples onto the co

having durations ranging from a fraction of a microsecond to a ground impedance paths of the grounding network. 

mill~second. Overvoltages of less than two per unit are not covered, 

nor are transients of longer duration resulting from power equipment Fast-acting protection dev~ces, such as current-l~

operation and failure modes. Because these low-amplitude and long, and circuit breakers capable of clearing or beginning to pa

duration surges are generally not amenable to suppression by conven- In less than mst leave trapped lnductlve energy In 

tional surge protective devices, they require different protection upsfream; upon collapse of the field, high are 

terhninlm~ Transient overvoltages associated w~th the sw~tchi

~~fi~i~i~~~ of terms used In the ~~~d~~i~~ are consistent with factor correction capacitors [I] have lower frequenc~es tha

i~~t standard 100-1977, ~i~~i~~~~~ of ,electrical and ~l~~~~~~~~ frequency splkes w~th wh~ch th~s document is concerned. T

Terms, 2nd ed.; however, some differences F~~ instance, :EEE at least In the caw of reztrike-free rw!tch!ng operations, ar

Std 100-1977 defines a surge as a "translent wave of current, potential less than twlce normal voltage and therefore are not of 

or power in the electric circult"-a definition broader than that used here, but be 

here. Transient Overvoltage is defined as "the peak voltage during the On the other hand, switchmg operations involv~n

transient condition resulting from the operation of a switching such as those produced by alr contactors or mercury sw

device4'-a definition more restricted than that of the Guideline. produce, through escalation, surge voltages of complex wav

While the ma,or purpose of the Guideline is to descr,be the en- of amplitudes several tmes greater than the normal syste

vironment, a secondary purpose is to lead toward standard tests, The severest case is generally found on the load side of the 

involves only the device that is being switched. Wh~le th

should certainly not be ignored, in such a case the prme re

for protection rests with the local user of the device i

However, switching transients can also appear on the l~n

devices connected to the line. The presence and source of 

may be unknown to the users of those devices. Thls 

harmful situation occurs often enough to command attention

A 79 428-4 A pap-- remnmm+d and +proved by the While the data have been recorded pr~marily on 120, 2

IKEE Surge Protective Wvices Committee of the IEEE ~/l/riau V systems, the general conclus~ons should be valid 

systems. To the extent that %large voltages are produced 5; 

PGG~~ Ciigiiierririg Society for presentation at tile IRE amount of energy being dumped into a power ]ow.im

PES Sunr~r FI~eti.~q, Vanca~~~~r, Pritish Co?;-bia, heavy industrial sysrems can be expected to experience lo

Canada, July 15-20, 1979. ~~~~~~~i~submitted ~~h~~~~~ 6, from surge voltages than 120 V residentla1 systems, but com

1979: made available for printing April 5, 1979. greater, amounts of energy potentially available for depo

surge suppressor. 

CH 1458-9/79/0000-4284$00.75 0 1979 l EEE 
OCCUP,P,ENCE AND VOLTAGE LEVELS 

IN UNPROTECTED CIRCUITS 

The rate of occurrence of surges varies over wide limits, 

depending on the particular system. Prediction of the rate for a 

particular system is always difficult and frequently impossible. Rate 

is related to the level of the ,surges; low-level surges are more prevalent than high-level surges. The relationship between the level 

and the rate of occurrence of surges is partly caused by the 

attenuation of the surges as they propagate away from the source of 

the surge and divide among paths beyond branching points. Equipment 

at a given point will be subjected to a relatively small number of highlevel surges from nearby sources, but to a larger number of surges 

from more remote sources. 

Data collected from many sources have led to the plot shown in 

Fig. 1. This prediction shows with certainty only a relative frequency 

of occurrence, while the absolute number of occurrences can be 

described only for an "average location." The "high exposure" and "low 

exposure" limits of the band are shown as a guide, not as absolute 

limits, to reflect both the location exposure (lightning activity in the 

area and the nature of the system) and the exposure to switching 

surges created by other loads. 

The literature describes ihr frequency of occurrence vs 

amplitude of !ightning strikes, from the low levels of a few 

kiloamperes, through the median values of about 20 kA, to the 

exceptional values in excess of iOO kA i2j. Clearly, a secondary 

arrester rated for 10 kA can protect adequately in case of a mild 

direct strike, or of a more severe strike divided among several paths to 

ground. However, a very high and direct strike will exceed the 

capability of an ANSI-rated secondary arrester [3 1. 

The voltage and current amplitudes presented in the Guideline 

attempt to provide for the vast majority of lightning strikes but should 

not be considered as "worst case," since this concept cannot be 

determined realistically. One should think in terms of the statistical 

distribution of strikes, accepting a reasonable upper limit for most 

cases. Where the consequences of a failure are not catastrophic but 

merely represent an annoying economic loss, it is appropriate to make 

a trade-off of the cost of protection against the likelihood of a failure 

caused by a high but rare surge. For instance, a manufacturer may be 

concerned with nation-wide failure rates, those at the upper limits of 

the distribution curve, while the user of a specific system may be 

concerned with a single failure occurring at a specific location under 

"worst-case conditions." Rates can be estimated for average systems, 

however, and even if imprecise, they provide manufacturers and users 

with guidance. Of equal importance is the observation that surges in 

the range of 1 to 2 kV are fairly common in residential circuits. 

From the relative values of Fig. I, two typical levels can be 

cited for practical applications. Firs?, "- UK e~~~~~~~;~,~ ..--"'-'.-- of a ? !:\I 

transient occurrence on a I20 V circuit ranges from 0.01 to 1 per year 

at a given location -a number sufficiently high to justify the 

recommendation of a minimum 3 kV wiiilsiand capability. Second, the 

wiring flashover limits indicate that a 6 kV withstand capability may 

be sufficient to ensure device survival indoors, but a 10 kV withstand 

capability may be required outdoors. 

I I I I 1 . 1.1.1 

I 2 34 6810 

<LUGE CREST kV 

Fig. 1. Rate of surge occurrence vs voltage ievei. 

Timing of Occurrence 

Surges occur at random times with respect to the power 

frequency, and the failure mode of equipment may be affected by the 

power frequency follow current or by the timing. Consequently, surge 

testing must be done with the ac voltage applied to the test piece. 

Lightning surges are completely random in their timing w~th 

respect to the power frequency. Switching surges are likely to occur 

near or after current zero, but var~able load power f

produce a quasi-random distribution. Some semiconducrors

in Appendix !!, exhibit failure !evels that depend on the tim

surge with respect to the conduction of power frequen

Gaps or other devices involving a power-follow current may 

this power follow with success, depending upon the frac

half-cycle remaining after the surge before current zero. 

it is important to consider the timing of the surge with res

power frequency. In performing tests, either complete ran

of the timing or controlled timing should be specified, with 

number of timing conditions to reveal the most critical timi

WAVESHAPE OF REPRESENTATIVE SURGE VOLTA

Waveshapes in Actual Occurrences 

Indoor - Measurements in the field, measurements in the 

and theoretical calculations indicate that most surge voltag

low-voltage systems have oscillatory waveshapes, unlike 

known and generally accepted unidirectional waves specifi

voltage insulation standards. A surge impinging on the sys

the natural resonant frequencies of the conductor system. 

not only are the surges typically oscillatory, but surges 

different ampiirudes and waveshapes ai diifeient places in 

These osrillatory frequencies of surges range from 5 kHz to 

500 kHz. A 30 to 100 kHz frequency is a realistic me

"typical" surge for most resideniiai and light I,,UUJ

netu?orks. 

Outdoor - Surges encountered in outdoor locations have 

recorded, some being oscillatory, others belng un~d~rec

"classical lightning surge" has been established as 1.2 x 

voltage wave and 8 x 20 ~s for a current wave. Evidenc

collected, however, to show that oscillations can also occur

reports 50 lightning surges recorded in two locations, the 

5.6 kV, with frequencies ranging from 100 to 500 kHz. Ma

reports oscillatory lightning surges in a house during a mult

flash. 

Because the overriding concern here is the energy 

with these surges, a conservative but realistic description of 

can be derived from the long-established specified duty of a 

arrester, as detailed below. While this specification is arbit

the strength of experience and successful usage, 

Selection of Representative Waveshapes 

The definition of a waveshape to be used as repres

the environment is important for the design of candidate 

devices, since unrealistic requirements, such as excessive 

the voltage G; very low source impedance, p!ace a high ener

ment on the suppressor, with a resulting cost penalty to th

The two requirements defined below reflect this trade-off. 

Indoor - Based on measurements conducted by several i

oiganization; in I20 and 240 V systems !.Appendix !!: the 

shown in Fig. 2 is reasonably representative of surge voltag

power circuits. Under the proposed description of a "0.5 u

ring wave," this waveshape rises in 0.5 us, then de

oscillating at 100 kHz, each peak being about 60% of th

peak. 

Fig. 2. The proposed 0;5 gs - 100 Hz ring wave 

(open-circuit voltage). 

- - - - -Aswe the effert~ ~rcoriat~d with 

lor I~>L I lJS prvuuLL .,.- 

voltage distribution in windings and the dv/dt effects on se

tors. Shorter rise times are found in many transients, bu

transients propagate into the wiring or are reflec

discontinu~ties in the wiring, the rise tlme becomes longer. 

The oscillating and decaying tail produces the effects 

polarity reversals in surge suppressors or other devices th

sensitive to polarity changes. Some semiconductors are p

sensitive to damage when being forced into or out of a c

state, or when the transient is applied during a particular 

the 60 Hz supply cycle (Appendix 11). The response o
suppressor can a!m be affected by reversals in the polarity, as in the 

case of RC attenuation before a rectifier circuit in a dc power supply. -. Ine pulse withstand capability oi many sem~conductors tends to 

improve if the wrge duration is much shorter than one microsecond. 

For this reason, the first half-cycle of the test wave must have a 

sufflclent duration. 

Outdoor - In the outdoor and service entrance environment, as well as 

in locations close to the service entrance, substantial energy, or 

current, is still available. For these locations, the unidirectional 

impulses long established for secondary arresters are more appropriate 

than the oscillatory wave. 

Accordingly, the recommended waveshape is 1.2 x 50 us for 

open-circuit voltages and 8 x 20 us for short-circult current (impulse 

discharge current) or current In a low-impedance device. The numbers 

used to descrlbe the impulse, 1.2 x 50 and 8 x 20, are as defined in 

IEEE Standard 28 - ANSI Standard C62.1; Fig. 3 presents the waveshape and a graphlc description of the numbers. 

Flg. 3. Waveshapes for outdoor locations. 

ENERGY AND SOURCE IMPEDANCE 

General 

The energy involved in the interaction of a power system with a 

surge source and a surge suppressor will divide between the source and 

the suppressor in accordance with the characteristics of the two 

impedances. In a gap-type suppressor, the low impedance of the arc 

after sparkover forces most of the energy to be dissipated elsewhere: 

for Instance, in a reslstor added in series with the gap for limiting the 

power-follow current. In an energy-absorber suppressor, by its very 

nature, a substantial share of the surge energy is dissipated in the 

suppressor, but its clamping action does not involve the power-follow 

energy resulting from the short-circuit action of a gap. It is therefore 

essential to the effective use of suppression devices that a realistic 

assumption be made about the source impedance of the surge whose 

effects are to be duplicated. 

The voltage wave shown in Fig. 2 is intended to represent the 

waveshape a surge source would produce across an open circuit. The 

waveshape will be different when the source is connected to a load 

having a lower impedance, and the degree to which it is lower is a 

function of the impedance of the source. 

To prevent misunaersranding, a distinct~on between source impedance and surge impednnce needs to be made. Surge impedance, 

also called characteristic impedance, is a concept relating the parameters of a long line to the propagation of traveling waves. For the 

wiring practices of the ac power circuits discussed here, this 

characteristic impedance would be in the range of 150 to 300Q, but 

because the durations of the waves being discussed (50 to 20 ps) are 

much longer than the travel times in the wiring systems being 

considered, traveling wave analyses are not useful here. 

Source impedance, defined as "the impedance presented by a 

source of energy to the input terminals of a device, or network" (IEEE 

Standard loo), is a more useful concept here. In the conventional 

Thevenins descriptim, the opencircuit v01:age !a: the t

the network or test generator) and the source impedance (

source or test generator) are sufficient to calculate the s

current, as we!! 3; any current for a specified siippiessoi im

The measurements from which Fig. I was deriv

voltage only. Little was known about the impedance of 

upon which the measurements were made. Since then, me

have been reported on the impedance of power systems

reports that the impedance of a power system, seen from 

exhibits the characteristics of a 50Q resistor with 50 pH 

Attempts were made to combine the observed 6 kV o

voltage with the assumption of a 508150 uH impedance 

combination resulted in low energy deposition capability

contradicted by field experience of suppressor perform

problem led to the proposed definition of oscillatory wave

high-energy unidirectional waves, in order to provide both 

of an oscillatory wave and the high-energy deposition capab

The degree to which source impedance is import

largely on the type of surge suppressors that are used. 

suppressors must be able to withstand the current passed th

by the surge source. A test generator of too high an imp

not subject the devlce under test to sufficient stresse

generator of too low an impedance may subject protectiv

unrealistically severe stresses. A test voltage wave speclf

refeience to source impedance could imply zero source 

one capable of producing that voltage across any impeda

short circuit. That would imply an infinite surge current

.,..*..-,:-*:- -:A..-L:. 

ut~~ cali>rlc ~ILU~LIUFI. 

Because of the wide range of posslble source impe

the difficulty of selecting a specific value, three broad ca

building locations are proposed to represent the vast 

locations, from those near the service entrance to those r

it. The source impedance of the surge increases from th

locations well within the building. Open-circuit voltages, o

hand, show little variation wlthin a building because 

provides little attenuation. Figure 4 illustrates the appl~

three categories to the wiring of a bullding. 

Flg. 4. Location categories. 

n n..*r._I^__AC^_..._^C -.--- ^. 

, ,. VYIJLUc O1lY _lCI **LC LIIII~IICC 8. ividjor Feeders and inort 

Serv~ce drop from pole to bulld~ng Dtstribtmon pane! rlevre

entrance Bus and feeder systems m 

iiun berween rnerer and d~srrlbu- plants 

tlon panel Heavy appliance outletr w

Overhead lme to detached buildings connections to the serv

Underground lines to well pumps Llghting systems In comm

C. Outlets and Long Brarch Circurts 

All outlets at rnore than 10 m (30 it) front 

Category B with wires 114-I0 
Subconimittee 28A of the International Electrotechnical Comrrtission has prepared a Repoii i8 j, in which instailation categories are 

defined. These installation categories divide the power systems 

according to the location in the building, in a manner similar 'to the 

location caregories deiined in rhe Guideline. However, rhere are some 

significant differences between the two concepts. First, the IEC 

categories are defined for a "controlled voltage situation," a phrase 

that implies the presence of some surge suppression device or surge 

attenuation mechanism to reduce the voltage levels from one category 

to the next. Second, the IEC report is more concerned with insulation 

coordination than with the application of surge protective devices; 

therefore it does not address the question of the coordination of the 

protectors but, rather, the coordination of insulation levels - that is, 

voltages. 

Surges propagate with very little attenuation in a power system 

with no substantial connected loads. Measurements made in an actual 

residential system as well as in a laboratory simulation have shown 

that the most significant limitation is produced by wiring flashover, 

not by attenuation along the wires. Ironically, a carefully insulated 

installation is likely to experience higher surge voltages than an installation where wiring flashover occurs at low levels. Therefore, 

the open-circuit voltage specified at the origin of a power system must 

be assumed to propagate unattenuated far into the system, which is 

the reason f~r maintai~ing the 6 k?' surge specificatim when going 

from one category to an adjacent category farther into the building. 

Furthermore, source impedances are not defined in the IEC 

report. The Guideline attempts to fill this need by specifying several 

levels of source impedance, or of short-circuit current, for the various 

categories. 

PROPOSED REPRESENTATION OF THE ENVIRONMENT 

On the basis of the preceding discussions, the Guideline 

proposes to reduce the infinite variety of actual conditions to three 

categories, from the outside service drops to the long branch circuits 

and outlets. 

For each category the most appropriate waveshape is indicated, 

an open-circuit voltage for high-impedance loads, or a short-circuit 

current for low-impedance loads. The tabulation that follows shows 

open-circuit voltages and short-circuit currents for each of the three 

categories. The energy deposited in a 500 V suppressor has been 

computed and is shown for each of the categories. 

The values shown in the table represent the maximum range, 

corresponding to the "High Exposure" situation of Fig. I. For less 

exposed systems, or when the prospect of a failure is not highly 

objectionable, one could specify lower values of open-circuit voltages 

with corresponding reductions in the currents. IEC Category I, not 

represented in the Guideline, would correspond to line cord-connected 

devices in this context; 

CONCLUSIONS 

The broad range of surge voltages occurring in low-voltage ac 

power circuits can be simulated by a l~m~ted setof test waves, for the 

purpose of evaluating their effects on equipment. 

Field measurements, laboratory experiments, and calculations 

indicate that two basic waves, at various open-circuit voltages and 

short-circuit current values, can represent the majority of surges 

occurring in residential, commercial, and light industrial power 

systems rated up to 600 V rms. 

Exceptions will be found to the simplif~cation of a broad 

iiiie; however, these should nor aeiracr from the benefits that c

expected from a reasonably valid uniformity in defining the en

ment. Other test waves of different shapes may be appropria

orher purposes, and the present guideiine should not be imposed 

it is not applicable. 

The Working Group is approaching the final phases of pr

tion of the Guideline document; comments are solicited fro

engineering and user communities. However, readers must rec

the unavoidably arbitrary character of any standard and be prepa

accept an imperfect approach, which can simpl~fy matters and 

the issues as well as provide uniform evaluations of perform

rather than demand a perfect but unattainable match betwe

actual situation and the standard. 

ACKNOWLEDGMENTS 

The concepts presented in this paper have greatly ben

from the informed questions and discussions by members 

Working Group on Surge Voltage in AC Power Circuits Rated 60

Less, and from interested reviewers; particular appreciatio

effective critiques from Catharine Fisher and Peter Richm

acknowledged. The data base presented in Appendix I has 

broadened by the contributions of the Bell Telephone Laboratori

Landis h Gyr, Inc. 

REFERENCES 

"Switching Surges Due to De-Energization of Capa

Circuits," AlEE Committee Report, AIEE Transactions, A

1957, pp. 562-564. 

Cianos, N. and E.T. Pierce, A Ground-Lightning Enviro

for Engineering Usage, Stanford Research Institute, Menlo 

CA 94205, August 1972. 

Surge Arresters for Alternating-Current Power Circuits, 

Standard 28-1 974; ANSI Standard C62.1-1975; IEC 

dard 99-2. 

Lenz, J.E., "Basic Impulse Insulation Levels of Mercury 

Ballast for Outdoor Applications," Illuminating Engrg., Feb

1964, pp. 133-1 40. 

Martzloff, F.D. and G.J. Hahn, "Surge Voltage in Resid

and Industrial Power Circuits," lEEE PAS-89, 6, July/Augus

! O+?-! 056. 

Bull, J.H., "Impedance on the Supply Mains at Radio Fre

cies," Proceedings of 1st Symposium on EMC, 75CH1012-4 

Mantreux, May 1975. 

Martzloff, F.D. and F.A. Fisher, "Transient Control 

Philosophy and Implementation: The Reasoning Behin

Philosophy," Proceedings 2nd Symposium on EMC, 77CH

5EMC, Montreux, June 1977. 

Insulation Coordination Within Low-Voltage Systems Inc

Clearances and Creepage Distances for Equipment, Intern

a1 Electrotechnical Commission Report SC28A (C

Office) 5, to be published in 1979. 

Recommended Surge Voltages and Currents Deemed to Represent the Environment 

I TY pe 

Impulse of Spec~men Energy 

Comparable to Waveform Max~mum* or Load Depos~ted in 

Location IEC SC28A Amplitude Clrcuit a 500 V Suppressor 

Category Category (~oules) 

A. Outdoor and IV 1.2 x 50 ps 10 kV O.C. High Impedance -- Service Entrance 8 x 20~s 10 kA s.c. Low Impedance 150 

I 1.2 x 50 'is 6 k?' O.C. L11611 IIIIyCVaI ,LC -- Ui-h ,---A ---- I 

6. Maior Feeders n x 2025 3 kA S.C. Low lmoedanc? 

I and Short 111 

I Branch C~rcuits L,:-L ,-..-A O.C. rU~ltIIIIIJCUbllCt: 0.5 ps - 100 kHz 

500 A s.c. Low Impedance 

Long 

Branch Circuits I1 

and Outlets 

6 kV O.C. High Impedance 

0.5~~ - 100 kHz { 200 A s.c. Low Impedance 

I *o.c .: open-circuit voltage s.c.: short-circuit current I 
Recordings arld surge counter data have been contributed from 

several sources; in addition to the surge counter data obtained by 

members of the Working Group. Representative oscillograms and 

summary statlstlcs are reproduced in this appendix, in support of the 

voltage levels and oscillatory wave proposals. 

1. Recordings by Bell Telephone Laboratories 

(Data contributed by P. Speranza, internal report, unpublished 

to date) 

1.1 Typical Surge Counter Statistics 

I20 V line at BTL facility in Chester, New Jersey, during 

42 months of monitoring: 

146 counts at 300 to 500 V 

14 counts at 500 to 1000 V 

3 counts at I00 to 1500 V 

3 counts above 1500 V 

1 .2 Typical Automatic Recording Oscilloscopes 

0 20 40 60 80 100 120 ps 

120 V OUTLET. LABORATORY BENCH 

2.1 Surge Counter Statistics - Martzloff, F.D. and G.J. Ha

Voltage in Residential and lndustrlal Power Circuits, iE

6, Ju!y,'P,ugu:t 1970, ! 049-! 056. 

a) Three percent of all US. residences experienc

occurrences (one per week or more) above 1200 V. 

b) There is a 100:l reduction in the rate of device fa

the withstand level is raised from 2 kV to 6 kV. 

Number of Houses with Repetitive 

Surge Activity Above 1200 Volts 

Providence, R. I Cleveland, Ohio Auburn. N. Y. 1,vnehbk. Vs. Syracuse, X Y Chicago, Ill. Ashland. Ma~s 

Fort Wayne, Ind IJeiiaii,, ill 

Surge Counter Recordings Above 1200 Volts 

(Sprmg, Summer, and Fall) - - - - - - -- 

Vlrmhcr id I,oc at ,on llornri - 

Prowdenre, I< I 1, 

. A.hh,,ro . . . . . , \ . . C . 1 { 

IkKalb, Ill. I I Somenworth, S H. { 

Chicago, Ill. I.' Cleveland, Ohm X 

lkcatw, Ill. 12 

Holland. Mwh. 

Lynchbury, Va. { 

Total !I I 

0 200 400 600 800 loo0 1200 ps 

277/480 V SERVICE ENTRANCE 

I --- -- 

I 2.2 Typ~caI Automatic Recording Osc~lloscopes 

2771480 V SERVICE ENTRANCE 

FURNACE IGNITION - SINGLE RECORDING 
SERVICE ENTRANCE, LIGHTNING STORM 

STREET POLE. LIGHTNING STORM 

2.3 Simulated Lightning Strokes on a Residential Power Circuit (Laboratory Model of System) - Martzloff, F.D. and K.E. Crouch, 

"Coordination De La Protection Contre Less Surtensions Dans Les 

~gseaux Basse Tension ~&~dentiels," Proceedings, 1978 lEEE 

Canadiun Conference on Communications and Power, 7dCH1373-0, 

1.5 kA current impulse (8 x 20 us 

approx.) is injected in round wire 

02 of service drop. 

ents produce flashover of wiring.) 

Recording of open-circuit voltage 

at a branch circuit outlet: 

2200 V peak 500 kHz oscillations 

By connecting a 130 Q load at the 

same outlet (1 A load) the voltage 

is reduced to 1400 V peak, with 

more damping. 

Conclusions from this test series 

I. A current of 1.5 kA (moderate for a lightning discharge 

injected in the ground system) raises the wiring system 

of rhe house 2.2 k'v' above ground. Four kiioamperes krill 

a moderate value) will bring this voltage to 6 kV, the 

typical flashover value of the wiring. 

2. A natural frequency of 500 kHz is excited by a unidirectlonal Impulse. 

3. In this example, the source of the transient (from the 

loading effect of 130 Q ) appears as 

2200 Z = l30Q IF- 400 I] 

= 75 Q 

3. Statistics by Landls & Gyr, Inc. 

Surge counter data on various locations In SWISS 220 V sys

(Data contributed by L. Regez - unpublished to date) 

PEAK VOLIAGE V 

--- ground system 

--- Same house, outlet th~rd floor l~ving room 

- - - - - - - - Same house, outlet fifth floor living room 

Service entrance of bank buildlnr! in Basel 

+- Landis and Gyr Plant, Zug, outlet in lab. ---_-, Landis and Gyr, Zug, outlet in furnace room 

--.- Farmhouse supplied by overhead lines 

Frequency of Voltage Transients per Year as a Function of the P

Value of the Voltage Transient for a 220 V, 50 Hz Distr~bution Sys

w~th Grounded Neutral 

4. Working Group Surge Counter Statistics 

Surge counters with four threshold levels (350, 500, 1000, 

1500 V) were made available to the Working Group by Jo

Electronic Systems, for recording surge occurrences at var

locations. Members of the Working Group installed these on 120 

240 V systems of various types, including the following: outlet

urban, suburban, and rural residences; outlets in a hospital; secon

circuits on distribution SYS~PEpole^ (recIoser Contr~!~)t secondar

pad-mounted distribution transformers; lighting c~rcuits In an in

trial plant; life test racks at an apphance manufacturer; bench po

suppIy in a !aboratorv I - Limitations on the availability of personnel and cornrnunica

made this sampling less than optimum from a statistical point of v

However, by computing weighted averages for each location, one 

quote an acceptable overall average; this average has been include

the graph drawn to establish the low and high exposure limtts. 

Summary Statistics of these measurements are as follows: 

I. Data base from 18 locations with a total recording tlme of 

I2 years spread over 4 calendar years, using 6 counters. 

2. Number of occurrences per year (weighted averages) a

"average location." 

3. Significant extremes 

One home with large number of surges caused by 

washer operarion 

Four locations out of I8 never experienced a surge. 

One home experienced severai occurrences abov

1500 V, with none below that value. 

One industrial location (switching of a test rack

produced thousands of surges in the 350-500 V range

and several surges in excess of 1500 V. Thls locatlon 

was left out of the average computation, but i

exemplifies a significant extreme. 
APPENDIX I1 - EFFECT OF TRANSIENT POLARITY REVERSALS 

ON SEMICONDUCTORS 

Breakdown of semiconductors under various conditions of load 

5.6 transient o\~er\~oltage app!ication: h;; been inv?;tigat&.*t EVidence is presented in the two investigations cited that a reverse 

voltage applied during the conduction period of the power frequency 

produces lower breakdown voltage than the application of ths same 

translent with no load or during blocking. Examples are given below, 

taken from these two investigations, showing statistically significant 

differences in the voltage levels. 

, , g

we,.+;fierS.u IPPP r~-n c c--.--L... ,-.--L A,L- LA JYYL 111a, I, J~~LCIIIUTIIUCLUU~~ i973, p. X2. 

~F.D. Martzloff, internal report, unpublished. 

Francois D. Martzloff (M, 1956) w

France and received his undergradua

at the Ecole Sp&iale De ~&a

d'Electric~te' In 1951; he received 

degree from Georgia Tech in 195

MSIA degree from Union College in 

Since 1956 he has been with 

eral Electrlc Company, where he fi

experience In the Transformer an

gear Divisions. Upon joming Genera

Coroorate Research and Develoome

he became mvolved In power semi

circuits and overvoltage protection

participated in the introduction and application of me

.,2r;e+,.7c VUL L~LW~ a c;--a JL~~LL I,, 1071 L . In IEEE Mr. Martzloff has been active on the Surge P

Devices Committee and chairman of the Working Group 

\lr\l+>nPr in ,&C D -..,- P;--..:rr "-+..A LAA\I -- 1 -.. . VLLU6LJ vrcc LllculrJ uuu v LV LC>>. He 

member of the Ad Hoc Advisory Subcommittee of the USA 

Committee on IEC SIC 28A. He has been awarded 10 U.S

primarily in the field of varistors and transient protection.