ML19273B265
| ML19273B265 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/13/1979 |
| From: | Vissing G Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7904060047 | |
| Download: ML19273B265 (36) | |
Text
/st))R(
O 4-MEETING
SUMMARY
DISTRIBUTION ORB #4 Mr. William Cavanaugh, III Vice President, Generation and Construction Department Arkansas Power & Light Company P. O. Box 551 Little Rock, Arkansas 72203 Docket-File
_fiRC Pnp V. Noonan L PDR P. Check ORB #4 Rdg G. Lainas NRR Rdg G. Knighton H. Denton Project Manager E. G. Case OELD V. Stello 0I&E(3)
B. Grimes R. Ingram T. Carter R. Fraley, ACRS(16)
R. Vollmer TERA A. Schwencer J. Buchanan D. Ziemann Meeting Summary File T. Ippolito Program Support Branch R. Reid NRC Participants L. Engle S. Rhow J. T. Beard D. Tondi M. Chiramal R. Fitzpatrick R. Spangler V. Thomas 790406'O77 O
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4 UNITED STATES
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WASHINGTON, D. C. 20555
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March 13,1979 Dockets Nos. 50-313 and 50-368 LICENSEE: ARKANSAS POWER AND LIGHT COMPANY (AP&L)
FACILITY: ARKANSAS UNITS NOS. 1 & 2
SUBJECT:
SUMMARY
OF MEETING HELD ON FEBRUARY 27, 1979, WITH AP&L ON STARTUP TRANSFORMER #2 (ST-2)
Introduction The subject meeting covered the subjects identified in the proposed planned agenda, Enclosure 1.
The attendees are identified in the attendance list, Enclosure 2.
AP&L presented a discussion of the subjects on the agenda with the aid of illustrations and visual aids, Enclosure 3.
Conclusions The staff requested and AP&L agreed to provide the following:
1.
Provide an analysis of voltages at the 4160 Volt and 480 Volt buses during tSe sequencing of the loads on these buses as it applies to the use of Startup Transformer No.1.
2.
Provide in a generalized manner and in narrative form the answers to each specific item of Part A of the agenda.
3.
Discuss criteria which an operator uses to prevent overloading of ST-2 during manual operation.
4.
Discuss the voltage analysis of the 4160 and 480 Volt buses applied from ST-2 as related to a postulated LOCA occurring before, during and after the transfer of power to ST-2.
5.
Document the F0A rating of ST-2.
6.
Prov He an analysis of ST-2 for the loads during the various stages of the transfer of the shutdown loads from one unit and the accident loads from the other unit.
Arkansas Power & Light AP&L agreed to provide the above information in a letter to us by March 13, 1979.
Discussion Item No. 7 of Part A on the agenda is documented more fully herein since it cannot be obtained directly from the illustrations.
The main concern with the offsite electrical power system for ANO-1/2 is that the degraded grid voltage for ANO-2 and proposed for ANO-1 is sensed at the 480 Volt lines which trips the 4160 Volt bus on low voltage. Most if not all, other plants have configurations which senses the low voltage at the 4160 Volt bus and trips the 4160 Volt bus on low voltage.
AP&L's rationale for their method is based on the need to provide the trip at 92% of the rated voltage at the 480 Volt bus which would first need the low voltage. Voltages below 92% in the 480 Volt bus would blow fuses which could not be imediately replaced. Thus the emergency equipment could be lost in case of a need at the same time.
If the sensor was placed on the 4160 Volt bus, the adjustment of the sensor would need to be such that the voltage on the 480 Volt bus would be 92% of the rated voltage as calculated. The calculation would be based on the worst case loading. Because the voltages relationship between the secondary and primary of a transfonner is not constant with varying loads, such a configuration could require a setting at the 4160 Volt bus to be higher than needed for most situations. The staff will take this rationale into consideration in reviewing the proposed
" Millstone" fix for ANO-1.
Guy S. Vissing, Project Manager Operating Reactors Branch #4
'livision of Operating Reactors
Enclosures:
1.
Meeting Agenda of 2/27/79 2.
List of Attendees 3.
General Design Criteria
Meetino Acenda with Arkansas Power & Licht Co.
Concernino Electrical Power System of ANO-1/2 February 27, 1979 A.
Presentation of AP&L which will cover the following questions and concerns:
1.
Show by calculational analysis the minimum voltage levels that would exist on each 4160V and 480V ESF bus if a LOCA were to occur, paying special attention to the voltage trantients during the startino of each.
ESF load.
State all assumptions, describe the cal-culational scheme, and evaluate the significance of the calculational results.
2.
Repeat Question #1 with the assumption that ST-1 is not available and all ANO-1 loads are automatically trans-ferred to ST-2.
3.
Repeat Question #1 with the assunption that ST-3 is not available ano all ANO-2 loads are automatically trans-ferred to ST-2.
4.
Justify, in terms of human factors engineering concepts, the desire that NRC allow credit for manual operator actions to overcome the apparent design inadequacy of ST-2 to accommodate its function for the present configuration and the proposed configuration.
5.
An interlock between ANO-1, ANO-2, and ST-2 has been proposed.
(a) Can the operation /maloperation/ failure of any part of the interlock (including each sensor) cause both ANO-1 and ANO-2 loads to be applied to ST-2.
(b) Can the operation /maloperation/ failure of any part of the interlock (including each sensor) prevent the manual loading of ANO-1 or ANO-2 ESF loads onto ST-2.
6.
What is the equivalent undervoltage setpoint at the 41.60V buses coordinated with your proposed setpoint at a value of 92% of rated voltage on the 480V buses.
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7.
Describe how the proposed undervoltage sensor on the 480V buses will detect all faults on the station service transforner, the 480V ESF systems, and unacceptable voltage degradation on the 4160V ESF systems.
B.
NRC Staff concerns and discussions.
C.
Conclusions.
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List of Attendees Meeting with AP&L Concernino ANO-1/2 Electrical Power System February 27, 1979 Name Organization Leon Engle NRC Sang Rhow J. T. Beard D. Tondi M. Chiramal R. Fitzpatrick R. Spangler Guy S. Vissing Vince Thomas Gus Lainas Ted Enos AP&L Michael 0. White Jim Grisham David Shehadeh -
Don Rueter Rodi A. Hamblen Muthuraman S. Iyer Bechtel Igor Don-Doncow C. Cleveland EG&G W. Reeves LLL J. Ibarra
1 GENERAL DESIGN CRITERIA #17
. AN OFFSITE ELECTRIC POWER SYSTEM SHALL BE PROVIDED TO PERMIT FUNCTIONING OF STRUCT1AES, SYSTEMS, N O COMPONENTS IMPORTANT TO SAFETY."
" ELECTRIC POWER FRCli THE TRN4Sti!SSION NETWORK TO THE ONSITE ELECTRIC DISTRIBUTION SYSTEM SHALL BE SUPPLIED BY TWO PHYSICALLY INDEPENDENT CIRCUITS...
tg 0F THESE CIRCUITS SHALL BE DESIGNED TO BE AVAILABLE WITHIN A FEW SECONDS FOLLOWING A LOSS OF COOLANT ACCIDENT..."
ARKANSAS NUCLEAR ONE STARTUP TRANSFORMER #2 WILL SUPPLY FULL SAFETY LOADS OF EDTH ANO-1 NO ANO-2 AT THE SAME TIME WITH NO UNACCEPTABLE VOLTAGES AT THE SAFETY BUSSES.
LIT T LE ROC K SOOKV MO R R I LTON.
FO R T SM IT H RUSSE L L-M ABLE VALE 161KV y
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45 H I 5 7 KV
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3 VOLTAGE CALCULATIONS COMPUTER ANALYSIS BECHTEL PROGRNi FOR DATA C0tNERSION AND COMPILATION BECHTEL, GE, NO PHIL. ELEC. CO. POWER FLOW PROGRAM FOR PROBLEM SOLUTION RESULTS ANALYZED, EVALUATED NO QAD
'f MINIMtF1 ACCEPTABLE VOLTAGES ON BUSSES SYSTEM MOTOR RUNNING STARTING BASE LOAD LOAD G.9 xv sus 6.6 xv 0.91 P.u.
0.82 'P.U.
4.16 xv sus 4.0 Kv 0.91P.U.
0.82 P.U.
430 v sus 460 v 0.92 P.U.
0.86 P.U.
5 REQUIRED VOLTAGES MOTORS RUtNING 90%
(MOTOR PASE)
STARTING 80%(MOTOR BASE) 480 V. FJS - 927 rum) 41F0 V, RIS - 917 rurm)
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< 2%
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460v 4000 v
G.
5
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8
7 INITIAL CCNDITIONS FOR VOLTAGE STUDY
- 1. AUTO TRANSFORMER IS OUT
- 2. TIE BEih'EEN 500 KV AND 161 KV SYSTEMS IS CUT
- 3. 161 KV SYSTEM IS IKTACT
- 4. MILLSTONE MODIFICATIONS ON ANO-1 ARE C0ohIt 5.
FAST TRANSFER TO ST 1/ST 3 IS NOT SUCCESSFUL
- 6. MINIMUM VOLTAGE ON 161 KV SYSTEM OF 1 P.U.
- 7. MINIMUM ACCEPTABLE VOLTAGE AT MOTOR TERMINALS RUNNING - 90% (MOTOR BASE)
STARTING - 80% (MOTOR BASE) 8.
INTERLOCKS INSTALL 9) TO KEEP BOTH UNITS FROM ACCESSING ST 2 AUTCt%TICAt.LY
CONSERVATI94
- 1. ASSlFED AUTO TRANSFORMER REMOVED 2.
PATED H.P. VICE OPERATING H.P.
- 3. USED HIGHER THN1 te ASURED LOADS ON 480 V. SYSTEM c
4.
USED ARITWETIC Sul VICE VECTORIAL SUM FOR 480 V. SYSTEM.
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ARKANSAS NUCLEAR ONE Uf11T 1 1400 ft/A FULL FOUSE XFER fl0 ES TIME =0 TPAf1SFOPMER: ST 2 EUS LOAD. (ff/A)
% VOLTAGE (MOTOR EASE) 6900 VOLT RUNNING LOAD =
15.51 v = 1.032 STARTING LOAD =
4160 VOLT RUNNING LOAD =
12.28 v = 1.006 STARTIfG LOAD =
480 v0LT RUNNIfG LOAD =
v =.944 STARTING LOAD =
RUNNING LOAD =
v =.944 STARTIflG LOAD =
//
ARKANSAS NUCLEAR ONE 1
i UNIT i
1400MVA FULL HOUSE XFER ES TIME = 5 TRANSFOPMER:
ST 2 BUS LOAQ (MVA)
% VOLTAGE (MOTOR BASE) 6900 v0LT RUNNING LOAD =
15.51 v = 1.028 STARTING LOAD =
i i
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4160 v0LT RUNNING LOAD =
10.28 v =.977 STARTI?E LOAD =
0.61 480 v0LT RUNNING LOAD =
0.756 y =.877 STARTING LOAD = 0.103 RUNNING LOAD =
0.647 v =.919 STARTING LOAD =
.034
l2 ARKANSAS fiUCLEAR ONE UNIT 1 14 W MVA FULL FOUSE XFER ES TIME = 10 TRANSFOP!d.ER: ST2 BUS LQAE (MVA)
% VOLTAGE (MOTOR BASE) 6900 VOLT RUNNING LOAD =
15.51 v = 1.028 l
STARTING LOAD =
4160 VOLT RUNNING LOAD =
10,88 v =.978 STARTING LOAD =
0.622 480 VOLT RUNNING LOAD =
.8601 y =.917 STARTING LOAD =
.0134 RUNNING LOAD =
.6807 y =.930 STARTING LOAD =
.0134
/3 ARKANSAS NUClIAR ONE UNIT 1 14 W MVA FULL HOUSE XFER ES TIME = 15 TPRISFOPf4ER: ST 2 E!.13 L0ld (MVA)
% VOLTAGE (MOTOR BASE) 6900 VOLT RUNNIfG LOAD =
15.51 Y = 1.031 STARTING LOAD =
4160v0LT RUNNING LOAD =
11.50 v = 1.000 STARTING LOAD =
l 480 VOLT RUNNING LOAD =
.8601 y=.%1 STARTING LOAD =
.0134 i
RUNNING LOAD =
.6807 y =.954 STARTING LOAD =
.0134
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ARKANSAS NUCLEAP ONE UNIT 1 14 W MVA FULL HOUSE XFER Tite = 20 i
TDR.SFOPP.ER : ST 2 El.13 LQaD_ (MVA)
'{ VOLTAGE (MOTOR BASE) 6900 v0LT RUNNIfG LOAD =
15.51 v = 1.T 9 STARTING LOAD =
4100 VOLT RUNNING LOAD =
11.50 v =.9828 STARTING LOAD =
0.456 480 VOLT RUNNING LOAD =
.8735 y =.T7 STARTING LOAD =
.03 RUNNING LOAD =
.6941 v =.940 STARTING LOAD =
'. 03
/5 ARKANSAS NUCLEAR ONE UNIT 1 1400MVA FULL HOUSE XFER ES TIME =
25 (STEADY STATE)
TPANSFOPf'E.R : ST 2 31.13 LOAQ (fWA)
% VOLTAGE (MOTOR EASE) 6900 VOLT RUNN!f5 LOAD =
15.51 V = 1.031 STARTING LOAD =
4160 VOLT RUNNING LOAD =
11.95 v = 1.000 START!fG LOAD =
I480 VOLT RUNNING LOAD =
.91 V = '945 STARTING LOAD =
RUNNING LOAD =
'bb3 V='N STARTING LOAD =
/G BUS VOLTAGES (MOTOR BASE)
ANO - 1 6900 v 4160 v 4160 v 480 v 480 v FULL HOUSE - S.S.
1.032 1.006 1.006 1.009 1.009 y
(NO ES)
,944
.344
- jf J elly /a e c/e d ES T=5 1.028 0.977 0.977 0.877 0.919 T = 10 1.028 0.978 0.978 0.917' O.930 T = 15 3 031 1.000 1.000 0.941 0.954 T = 20 1.029 0.9828 0.9828 0.927 0.940 T = S.S.
- 1. ~";l 1.000 1.000 0.945 0.962
/7 l
t ARKANSAS NUCLEAR ONE f
UNIT 2
1400 fWA FULL HOUSE XFER NO ES Tres = 0 TPAISF0FMER: ST 2 i
BUS LQaD. (f*/A)
% VOLTAGE (MOTOR PASE)
+
6900v0LT RUNNING LOAD =
29.87 v =.972 STARTING LOAD =
4160 VOLT RUNNING LOAD =
.7376 v= %5 STARTING LOAD =
RUNNING LOAD =
.7376 y =.%5 STARTING LOAD =
480 VOLT RUNNING LOAD =
.65 y =.926 STARTING LOAD =
RUNNING LOAD =
.65 v =.926 STARTING LOAD =
/E-ARKANSAS NUCLEAR ONE UNIT 2 1400fWA TIME = 0 TPANSFOPf4ER:
% VOLTAGE (NOTOR EASE) 6900 VOLT RUNNitAi LOAD = 25.208 v =.998 STARTING LOAD =
4160 v0LT RUNNING LOAD =
.738 v = 1.011 STARTING LOAD =
RUNNING LOAD =
.738 v = 1.011 STARTING LOAD =
480v0LT RUNNING LOAD =
v=
g gg STARTING LOAD =
RUNNING LOAD =
.525 v=
.929 STARTING LOAD =
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1 ARKANSAS fiUCLEAR ONE UNIT 2
14W MVA ES I
TIME = 10 l
TPMISFOPMER: ST 2 I
i HUS LQaD. (MVA) 73 VOLTAGE (MOTOR EASE)
I 25.208 y =.992 6900v0LT RUNNING LOAD =
STARTING LOAD =
4160 VOLT RUNNING LCAD =
.738 V =,951 STARTING LOAD =
.524 RUNNING LOAD =
.738 v =.951 STARTING LOAD =
.524 480 VOLT RUNNING LOAD =
.525 v =.918 STARTING LOAD =
Ruff 1ING LOAD =
.525 y =.918 STARTING LOAD =
- 2. :
ARKANSAS NUCLEAR ONE UNIT 2 1400MVA ES TIME = 15 TRANSFORMER: ST 2 31.13 LQGJ1(MVA)
% v0LTA3E (MOTOR BASE) 25.208 y =.993 6900v0LT RUNNING LOAD =
STARTING LOAD =
4160 VOLT RUNN!NG LOAD =
1.261 v =.959 STARTING LOAD = 0.403 RUNNING LOAD =
1.261 v =.956 STARTING LOAD = 0.446 480 VOLT RUNNING LOAD =
.525 y =.928 STARTING LOAD =
RUNNING LOAD =
.525 y =.926 STARTING LOAD =
2l ARKANSAS NUCLc.AR CNE UtilT 2 14C0 fWA ES TIME = 25 TPRISF0FP.ER: ST 2 huS LQen (MVA)
% VOLTAGE (MOTOR PASE) 6900v0LT RUNN!!G LOAD =
25.2 8 v =.992 STARTING LOAD =
4160v0LT RuN:11NG LOAD =
1.644 v =.953 STARTItG LOAD =
.401 RUNNING LDAD =
1.644 v =.953 STARTING LOAD =
.401 480 VOLT RUNNitG LOAD =
.525 y =.!*.B
'b l
STARTING LCAD =
.525 y =,gg RUNNING LOAD =
STARTING LOAD =
.025
2:
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ARKANSAS NUCLEAR ONE UNIT 2 1400 ft/A ES i
TIME =
50 TPRISFOPf4ER: sr 2 EMS LQea.(MVA)
% VOLTAGE (MOTOR EASE) 6900v0LT RUNNifG LOAD =
25.208 v =.996 l
STARTING LOAD =
i t
4100 v0LT RUNtJING LOAD =
2.045 v =.993 STARTING LOAD =
RIfiti!NG LOAD =
2.045 v =.993 i
STARTING LOAD =
480 VOLT RUNh!NG LOAD =
.550 v =.904 STARTING LOAD =
.11 RUf011NG LOAD =
.550 y =.904 STARTING LOAD =
ell
- 2. 3 i
ARVANSAS NUCLEAR ONE UtJIT 2 14W tt/A ES TIME = 70 TRANSFOP!',ER:ST 2 E!LS LQAq (tf/A)
% VOLTAGE (MOTOR BASE) f 6900v0LT RUNN!tG LOAD =
25.203 v =.996 l
STARTING LOAD =
1 4100 VOLT RUNNING LOAD =
2.045 v =.998 STARTING LOAD =
l i
{
RUNNING LOAD =
2.045 v =.995
[
STARTING LOAD =
n b
480 VOLT RUNN!?G LOAD =
.6E V =.9N STARTING LOAD =.05 RUNNING LOAD =
.634 V =.906 STARTING LOAD =
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ARKANSAS NUCLEAR Of'E I
UNIT 2 i
14@ MVA l
ES i
Tres =
80 TPRISFOP."ER : ST 2 i
SUS LOAD. (ff/A)
% VCLTAGE (W; TOR BASE) 6900 v0LT RUNNING LOAD =
25.203 v =.996 i
STARTING LOAD =
l s
e i
t 4160 v0LT RUNNING LOAD =
2.045 v = 1.00 i
STARTING LOAD =
RUNNING LOAD =
2.045 y = 1.00 STARTING LOAD =
I
'S v='b9 480 v0LT RUNNING LOAD =
STARTING LOAD =
PUNNING LOAD =
.734 v=.937 STARTING LOAD =
.036 e
25 t
I ARKANSAS NUCLEAR ONE UNIT 2
1400MVA ES Tite = 90 i
TPANSFOPfER: ST 2 i
EUS LQaD. (MVA)
% v0LTAGE (MOTOR PASE) l 6900 v0LT RUNNING LOAD =
25.203 v =.993 STARTING LOAD =
i i
i 4160 VOLT RUNNING LOAD =
2.045 v =.948 STARTING LOAD =
.529 RUNNING LOAD =
2.045 y =.981 STARTING LOAD =
l l
480 VOLT RUNNING LOAD =
.724 v =.897 STARTING LOAD =
.01 RUNNING LOAD =
.77 v =.929 STARTING LOAD =
.01 i
t t
2G i
ARKAf!SAS NUCLIAR ONi UNIT 2 l
14@ tWA l
ES TIME =
STEADY STATE i
TRAtJSFOP! DER: ST2 l
E!.$
LOM (tWA)
% VOLTAGE (MOTOR EASE) i 6900 volt RUNNING LOAD =
25.208 v =.996 STARTING LOAD =
i 4160v0LT RUNNING LOAD =
2.574 y
1.000 START!?iG LOAD =
c RUNNING LOAD =
2.045 y = 1.003 STARTING LOAD =
'M v='95 480 VOLT RUNNING LOAL =
STARTING LOAD =
RUNNING LOAD =
.78 v =.957 STARTit'G LOAD =
27 I
113 VCLTAGES (MOTOR BASE) mo-2 6900v 4160 v 4160v 480 v 480 v FULL HOUSE - S.S.
(NOES) 0.972 0.965 0.965 0.926 0.926 ES T=0 0.993 1.011 1.011 0.929 0.929 l
T = 10 0.992 0.951 0.951 0.918 0.918 T = 15 0.993 0.959 0.956 0.928 0.926 j
l T = 25 0.992 0.953 0.953 0.908 0.908 I
T = 50 0.996 0.993 0.993 0.904 0.904 r = 70 0.996 0.998 0.995 0. 93 4 0.906 T = 80 0.996 1.000 1.000 0.959 0.937 F
T = 90 0.993 0.943 0.981 0.897 0.929 T=ss.
0.996 1.00 1.003 0.958 0.957
1(ul M si dW SU2 i
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6,9 KV 4.16 KV 1-5 I,
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3 23 111 211 Ill 2:1 13 23 13 al al cl of ol ol oi a 4 Hi H2 2HI 2H2 Al A2 2Al 2A2 UNIT I UNIT 2 UNIT I UNIT 2 I A P I,2 A P 1 tJ,0. CON TA C 15 IN 5 FRIES WITH 3----
CLOS E All TOMA 1 IC T R A N S F F. R LEG OF EACH kT_TH),4 Hg Ap' A
EREAKER IN UillT TW0-L o
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t A LA RM
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c; (I API)
A PI titalT l-SIMILAP FOR 2 UNIT I UNIT 2 1h
TEMPERATURE EFFECTS STni LOAD: 30 ft/A 6.9 KV WitOING 21 tWA 4,16 xv Wit 0!!.G ANALYSIS PERFORt1ED AT:
20 M!?UTES 30 MiturES 40MitUTES RESULTS:
TRANSFORMER CAN SUSTAIN LOAD FOR 40 MinurcS WITH ((q LOSS OF LIFE
3c 92% OF 460 = I423.2 v0LTS I
TRAtiSFCRMER 14160 - (180 vcLTs I
PR!f%RY VOLTAGE = 1423.2 X k ]
= 3667.7 v0LTS OR 36gc 7 = 91.69% OF 4000 v0LTS 3 W.7 88.16 % OF 4160 VOLTS.
I
=
4160 AT to LOAD hHEN TRAt1SFORMER IS LOADED IT WILL IffTRODUCE A VOLTAGE DROP 123, ATO THEREFORE, THE DRIVIf4G VOLTAGE AT 4160 I
VOLT LEVEL WILL BE HIGHER TPM4 88.16% TO PRODUCE A E OF 460 ON.1480 v0LT I