NUCLEAR POWER PLANT BAlTERY PERFORMANCE DURING A STATION BLACKOUT

bY

Richard A. Johnson Member, IEEE

Bechtel Corporation

Norwalk, California

Abstract- The imposition of NUMARC8700 on most Nuclear Power Plants results in a significant impact on the capacity of

existing safety related batteries. Since these batteries typically have

limited design margins, extensive analysis and operator action can

be required in order to comply with the 4 hour duty cycle

requirement. This paper discusses some methods of reducing the existing load profiles and the conversion to Lotus 123 to facilitate

the running of multiple scenarios in order to comply with the blackout requirements.

l" A Station Blackout at a Nuclear Power Plant is defined as a loss

of both off-site power supplies to the Safety Related Electrical

Distribution System and Failure of the Emergency Diesel Generators.

The one line diagrams provided in Figures 1 and 2 show a single

train of typical class 1E AC and DC systems. Per NUMARC8700

most utilities without an alternate AC power source must now show

that they can cope with a Station Blackout for a 4 hour period. To

this end, load profile reductions and the conversion of existing manual battery sizing calculations to Lotus 123 are discussed.

Sizing station batteries in accordance with IEEE 485 requires

individual load tables to develop the final load profile and a cell sizing sheet to determine the maximum section size, which dictates

the batteries' size. In the past this effort has been done manually.

The Lotus method discussed here requires the creation of the

following five (5) types of tables within a single Lotus Spread Sheet:

1. Data Entry or Individual Load Evaluation

2. Load Profile 3. Load Profile Graph

4. S Curve Look Up table 5. Battery Cell Sizing Sheet

Emergency DkJSOl

Generator

W V Loadcenter + /'

12WAC & via Bus

Regulating Transformer

Figure

Charger r ,&, Charger

1 - AC System

Shutdown Cooling

Valve Inverter

1 MVAC V i Bus

Regulating Transformer I Vial 1 MVAC Bur

Aux. Relay Panel 1 Aux. Relay Panel 2

Reactor Trip Load Sequencer

125VDc Panel

Figure 2 - DC System 90CH2975-1/90XXXX)-0991$01.~ Q 1990 IEEE

Using Lotus look up features, summary data from one table is transferred to another table. An example including the resulting load profiles, is included as Appendix 1. The resultant Lotus battery sizing

calculation has the following features:

1. The Lotus routine has the capability of automatically adding current values for different times from individual load summary

tables to form the load profile table.

2. The cell sizing sheet is completed from the load profile table and Lotus automatically establishes the maximum section size to

determine the required battery size.

3. Normal and blackout load profile graphs are generated from data in the load profile table.

4. Subsequent blackout duty cycle load reduction analysis is facilitated since changing a value in an individual load summary

table automatically changes the values on the cell sizing sheet as

well as generating new load profiles and graphs.

Selection Of The Number Of Ce Ilg

Since they require less maintenance then Lead Antimony cells, Lead Calcium batteries are now typically used in safety related

systems at Nuclear Power Plants. However, as shown in Figure 3, due to a significantly less float demand current then previously seen

on Lead Antimony batteries, some Lead Calcium cell plate

configurations are susceptible to electrolyte stratification problems.

Float C u r r e n t D e m a n d For Fully C h a r g e d C e l l s .

I 2.1s: : 2.25 2.35 2. *5 04 : :

FSbi t c a d

noat V o l t a g e (IC@

C a - C a l c i u m Float V o l t a g e Range Sb-Antimony Float V o l t a g e R a n g e

Figure 3 - Cell Float Currents

For a 60 cell battery, to ensure that frequent equalizing charges

are not required, corrective action might be to raise system float

voltage from 130.2 volts (2.17 vpc) to 135 volts (2.25 vpc), thereby

increasing the float demand current. The increased float demand

:went would cause more electrolyte mixing, correcting the Blectrolyte stratification problem. However, typical relay qualification

wograms to meet IEEE 323 justify continued operation at 130 vdc

with periodic short duration operation at 140 vdc. Therefore, floating the batteries at their maximum float voltage of 2.25 vpc may result

n shortening the lifetime of continuously energized relays. An nlternative is to remove some cells, provided the resultant reduced

design margin is acceptable. In this case, a 59 cell Exide GC-23

battery floated at 129.8 volts (2.20 vpc) is used.

Blackout Load Profile Chanaes

Load lncreaseg

Since the blackout load profile must include plant recovery (Le.,

Emergency Diesel Generator starting and load sequencing) at the end of the duty cycle, the additional load for Emergency Diesel Generator and Circuit Breaker Control must be added to the normal

load profile during the last minute of the blackout load profile.

Inverter Load Reduction

A review of the Normal Load Profile indicates that the inverter

loads, based on their rating, are 82% of the steady state load profile amps. Therefore, any reduction in the inverter amps will have a

substantial effect on the overall duty cycle. The following two factors were considered in reducing the inverter currents:

1. Averaae Dutv Cvcle Voltaae Since inverters are constant KVA devices, their input current is

inversely proportional to the DC input voltage. That is, initially when

the system is at Normal Float Voltage the current is lower then at the End of Duty Cycle Voltage. Typically the End of Duty Cycle

Voltage has been used to establish the inverter current; however,

an inverter current based on the Average Duty Cycle Voltage is representative of the overall change in the battery’s amphours.

Therefore, it may be used to establish the inverter current to

determine the battery size. The Average Duty Cycle Voltage is

calculated by averaging the Initial Duty Cycle Voltage with the Final

Duty Cycle Voltage.

The Initial Duty Cycle Voltage (VID) is calculated by first

determining a function for initial cell voltage using least squares

curve fitting of the initial voltage curve as shown on Exide S1027

(Average Capacity of Mean Size Cells for GC-17 to 23 Batteries).

Since the resultant equation

Where:

VPC=volts per cell and APP=amps per positive plate

992

is within 5% of manually read values (i.e., within the calculation’s

accuracy) it was loaded directly into the Lotus Spread Sheet. Since

APP equals the First Minute Load divided by 11 Positive Plates (for

a GC23 cell), then

VID=(59 cells) X 2.02e-0.000064FML

VID= 119.18e-0.000064FML

VID=114.68 V

Where: FML=Flrst Minute Load

Note: The 59 cells and 11 positive plates apply only to the battery

configuration considered in this paper.

The Final Duty Cycle Voltage (VFD) is calculated by multiplying

the per cell final duty cycle voltage (1.84 volts per cell in this case)

by the number of cells (59 in this case). The resultant voltage

(108.56) accounts for 3 volts drop to 105 volts (minimum inverter operating voltage) due to cable resistance.

This results in an Average Duty Cycle Voltage (VAC) of

WD + VFD) / 2 = 111.62V

or a 2.8% reduction in the inverter current. Because the conditions during valve operation could not be assessed, this factor was not applied to the inverter random load.

2. Measured Inverter Current Due to a high load diversity on class 1 E instrument panels, using

a measured inverter current (taken at worst case operating

conditions) typically results in a substantial load reduction. However,

to account for load growth after the measurement and the voltage

at the time the measurement was taken, the following corrections

must be applied to the measured inverter current (IM):

Inverter Current=IM V A C ) (ICPDCM)

Where:

VM=Voltage when Inverter current was measured.

ICM=Connected load when measurement was taken.

ICP=Present connected load current.

For the case considered in this paper, this results in an 18%

reduction in the inverter current.

ODerator Action Load Rduct ion

Since the Emergency Diesel Generators are not running during

the Station Blackout, operator action (assured after 30 minutes) can

demergize the Soak Back and Fuel Priming Pumps thereby reducing the steady state amps required during a blackout.

Additionally, operator action during the recovery, to prevent circuit

breaker spring charging and load sequencing until after the battery chargers are energized will further reduce both the circuit breaker

control loads and the sequencer loads.

Batterv Aai na Factorq

IEEE 485 requires that a 1.25 (V.8) aging factor be used based

on a battery reaching 80% of its rated capacity at the end of its

life. Since Nuclear Power Plants typically have a 40 year life and

batteries a 20 year life, one battery replacement is normally required.

where the blackout evaluation indicated that additional battery capacity is needed, current practice is to add a new battery system

(including DC Switchgear, Battery Charger and potential WAC modifications). An alternative to this is to commit to one additional

battery replacement, which would result in a 13.3 year battery lifetime. Upon review of the battery capacity cutve shown in Figure 4, it can be seen this would result in an improvement in the aging

factor from 1.25 to 1.05. This is roughly a 19% increase in the

battery’s capacity. Provided the additional capacity is sufficient, it

is clear that one additional battery replacement would result in a

substantial cost savings over adding a new DC system.

BATTERY CAPACITY CURVE 110

I im

Bo

90

m UI 60 a, 1m

PERCgNT LIPE

Figure 4 - Battery Aging

Since IEEE 450 requires that the battery performance test interval

be reduced from once every five years to once a year whenever

the batteries capacity is 85 percent of rated, reducing the aging

factor would necesitate conducting battery performance tests at one

year intervals. Additionally, since some cells may have an initial

capacity of 90 percent of rated, it may be prudent to use a 1.11

aging factor(i.e. based on 90 %).

993

To ensure that the additional battery capacity is available for

blackout, the calculation included with this paper uses an aging factor of 1.25 for the normal cell sizing sheet and 1.05 for the

blackout cell sizing sheets.

Desian Maraing

The two blackout cell sizing sheets (i.e., Blackout Without

Operator Action and Blackout With Operator Action) calculate design margins by dividing the actual number of positive plates by the

required number of positive plates. The lower value (Blackout

without Operator Action) is then automatically inserted on to the

normal cell sizing sheet. This ensures that future load changes do

not result in an inability to meet blackout requirements. Should a load addition result in a load growth in excess of the design margin, the project could then commit to further load reductions by operator

action. In this case the design margin would increase by 2% form 1.03 to 1.05. In addition, the Normal Cell Sizing Sheet indicates a

Percent Unusable Battery Capacity due to blackout constraints.

A review of the above discussion indicates the following significant points that are worth restatement:

1. Typical Nuclear power plant battery sizing calculations are

inherently conservative and may have sufficient capacity to meet blackout requirements with limited additional analysis or operator

actions. In this case the blackout load profile can deliver as much

as an additional 123% of the normal load profile amp hours.

2. Because the load tables and cell sizing sheets are all contained

within a single Lotus spread sheet, previous tedious manual calculation analysis is eliminated since Lotus automatically makes

all subsequent load value changes. This facilitates running multiple

potential blackout load profiles to ensure that optimum battery

performance can be attained.

3. Committing to one additional battery replacement can result

in a significant cost savings over adding a new battery system.

REFERENCES

1. NUMARC 8700, Guidelines and Technical Bases for NUMARC

Initiatives Addressing Station Blackout at tight Water Reactors,

November 20, 1987.

2. EXIDE Stationary Lead Acid Battery Systems, Section 50.00,

February 1985.

3. EXIDE Type GC General Purpose Calcium Flat Plate Cell 994

--

Performance Data, Section 51.50, August 1978.

4. IEEE 450-1975, Recommended Practice for Maintenance,

Testing and Replacement of Large Lead Acid Storage Batteries for Generating Stations and Substations.

5. IEEE 485-1978, Recommended Practice for Sizing Large Lead Storage Batteries for Generating Stations and Substations.

c h a r d ( J o h n s o n - 8 8 ) Ri was born in Yonkers, New York on December 2, 1949. He received a BS degree in Electrical

Engineering in 1972 and a Teaching Certificate in Mathematics and

Physics in 1973. Subsequently he was commissioned as a Naval Officer and received Navy Nuclear Power Plant and Submarine

training in 1975.

From 1976 to 1979 he served as the Electrical and Reactor Safety Officer on the USS Sargo SSN 583 out of Pearl Harbor Hawaii. In

1979 he joined Bechtel Corporation and is now the Electrical Discipline Supervisor for the San Onofre Nuclear Power Plant.

Mr. Johnson is a member of the IEEE Power Engineering Society, the American Nuclear Society and Eta Kappa Nu.

Appendix I

CLASS 1E 125VDC BATTERY S I Z I N G CALCULATION

I . INTRODUCTION AND CALCULATION METHOD

This calculat jon fol lows the method described i n IEEE 485 t o define the DC load r o f i l e and s ize a batter representative of that used in a class 1E 125VDC system and produce graphs, the calculat ion has been developed using a LOTUS spreadsheet.

The calculat ion uses essent ia l ly the fo l lou ing f i v e (5) types of tables:

Because o f L o t F 123's capab i l i t y t o rransfer data betueen tabyes u i t h i n a spreadsheet

1. Data Entry o r Load Evaluation 2. Load P r o f i l e 3. Graph 4. S Curve 5. Cel l s iz ing sheets

Because of nesting o f the tables t o other dependant tables including txe cel? s iz ing sheets.

an chan e t o - a data entry tab le automaticly resul ts i n changes

11. DC LOAD EVALUATIONS

This section contains ind iv idual time current evaluation tables f o r each load shown on the DC S stem One Line Diagram. The sumnary load values f o r each table are-automatic1 used t o establ ish the battery load p r o f i r e table. The development of each tab le i s b r i e f l y discussed berow:

1. C i rcu i t Breaker Control and Diesel Generator Control Panel Loads The i n i t i a l conditions assune that an Emergency Diesel-Gekrator s ta r t jng sequence i s i n i t i a t e d a t t=o on the blackout duty cycle condit ions-to establ ish the one (1) minute L o 3 t o be used in the Battery duty cycle. values are calculated.

Since the resultant load-seqwni i s a t f i v e (5) second in terva ls the tables use the uorse case transient In addition, steady state Load

2. Miscellaneous Relay Cabinets And The Sequencer

3. NSSS Inverter

One (1) minute and steady s ta te Load values are determined based on i n i t i a t i o n o f Emergency Diesel Generator s ta r t ing a t t=o.

Rated inver ter current i s used t o extabl ish the battery size- houever due t o i t s high percentage o f the t o t a l DC load and i t s h i h load d i v e r s i t a reduced current value i s used t o r the blackout evaluations e s t a b l i s h 4 by correcting !he measured inverfer current f o r chan es in the connected l o a i a@ basing the current onman average duty cycle voltage rather then the m i n i m dut cycle voftage The average voltage is calculated by averaging the i n i t i a l one (1) minute load voltage u i t h the end or duty cycle voitage.

Rated load current accounting f o r inver ter ef f ic iency i s the basis f o r the current value established f o r t h i s random load.

The r*ed current value i s

4. Shutdom Cooling Valve Inverter

C i rcu i t Breaker Control Loads 4.16 KV Breakers 480 V Breakers

Time Channel A Channel B Channel A Channel B

0.1-1.1 161.00 81.00 81.50 81.50 1.1-5.0 21.00 11.00 11.50 11.50 5.0-5.1 31.00 21.00 11.50 11.50 5.1-6.1 161 .OO 161 .OO 1.50 1.50 6.1-10.0 21.00 21.00 1.50 1.50 10.0-10.1 31.00 31.00 1.50 1.50 10.1-15.0 1 .oo 1 .oo 1.50 1.50 15.1-20.0 6.00 6.00 4.10 4.10 20.0-20.1 1 .oo 1 .oo 1.50 1.50 20.1-25.0 6.00 6.00 1.50 1.50 25 -0-25.1 1 .oo 1 .oo 1.50 1.50 25.1-30.0 6.00 6.00 1.50 1.50 30.0-30.1 1 .oo 1 .oo 1.50 1.50 30.1-35.0 6.00 6.00 1.50 1.50 35.0-60.0 1.00 1 .oo 1.50 1.50 Max 1 Min 161.00 161.00 81.50 81.50 (Per Chan) Max 1 Min 161.00 81.50

,-$S;?C-) '%$o (AT$o (Arrqsao cArrqsao

I P r n f i l e . )

Diesel Generator Control Panel Load (Amps)

Time Soak BackFuel Prime Control Fld. Flash

' z 6 0 ' T O O L0?80 Lo?OO 0-0.6 0.6-1.0 12.60 0.00 2.80 0.00 1.0-1.6 12.60 75.60 2.80 0.00 1.6-3.5 12.60 12.60 2.80 0.00 3.5-10.0 12.60 12.60 2.80 5.00 10.0-60,O 12.60 12.60 2.80 0.00 Max 1 Min M A M A 1-90 Min :!!A60 NC!!.60 5.80 6.00

Blackout Reduction After 30 Min 25.20

Blackout Recovery 91.00

(Sec.)

(Uith Operator Action)

(Last Minute)

.. ..-, 1-90 Min 1 .OD 1.50

Blackout Recovery 31.00 -No Owrator Action (Last Minute) .

Blackout Recovery (Last Minute)

Note: The 161.00 and 81.50 amps are due t o the spring charging motors.

10.33 -With Operator Action

Reactor T r i p C i rcu i ts Aux..Relay Cabinet 1 Aux, Relay Cabinet 2 Sequencer Time Current Time Current Time Current Time Current

1 Win c A K 8 0 1-90 Min 2.50

(Mjn.) (Min.) 1 Min 'A"t;s80 1-90 Min 2.80

'":30 (Min.)

1 Min 1-90 Min 12.20

yy,' (Amp:$O 1-90 Min 0.00

Blackout Recovery 10.00 -No Operator

Blackout Recovery 2.50 -Ui th Operator (Last Minute) Action

(Last Minute) Action

NSSS Inver ter

(A s

Shutdoun Cooling Valve Inverter Rated Conditions Uhen Load Measured Present Average Average

Time Current Measured Con. Load Voltage Con. Load Current Time Current Current

1 Min 1-90 Min 19.05 18.53

(Min.' 1 -85 (Ar43 ' 8 2 3 5 l % J O (:8:80 (V%S$o ':!!?do (:?85 (Min.)

1 Min 1-90 Min 204.75 128.00 147.00 133.00 156.00 161.85

Normal Value= 204.75 Blackout Value= 161.85 Random 56.80

Battery Size=GC- 23 No. Pos. Plates= 11 Average Voltage= 111.62

995

111. LOAD PROFILE TABLES

The fol lowing three load p r o f i l e tables are developed

1 Normal Load P r o f i l e - basis f o r bat ter s ize 2: Blackout Load P r o f i l e (Operator Actionr - accounts for the non operator act ion blackout load reductions shown on the Load 3. Blackout Load-Profi le (with 0 ra to r Action) ; accounts for a l l blackout load reductions including operator act ion af ter

An Wa Curve Table i s included (valves read from Exide Average Capacity o f Mean Size Cel ls f o r GC-17 t o 23 bat ter ies) so that the Lotus aaLookupaa feature can be used on the battery c e l l s iz ing sheets. data must be added t o t h i s table.

Evaluation Tables.

t h i r t y (30) minutes shown on g e Load Evaluation Tables.

Uhen ever new periods are added t o the load p r o f i l e new

The three Load p r o f i l e graph tables are included t o f a c i l i t a t e generation o f the load prof i les .

Normal Load P r o f i l e

(Min.) (Min.) Breakers Breakers Trip Generatorcabnet 1 Cabnet 2 Sequencer Inver ter Inver ter Total 1 Min 1 161.00 81.50 3.80 91.00 25.30 8.00 10.00 204.75 19.05 604.4 1-90 Min 89 1 .oo 1.50 0.00 28.00 12.20 2.80 2.50 204.75 19.05 271.8

56.8 56.8 Random 1

Tjme Duration 4.16 KV 480 V Reactor Diesel Aux Aux NSSS Valve

Blackout Load Pro f i le - No

30 Min 29 271.80 43.42 228.38 30 Min 29 271.80 43.42 228.38 1 '%lo '9; /2 48 1 M i n

Blackout 209 271.80 43.42 228.38 Blackout 209 271.80 68.62 203.18 1 271.80 -60.41 332.21 1 56.8 0.00 56.80

Last Min 1 271.80 -88.58 360.38 Last Min Random 1 56.8 0.00 56.80 Random

ra tor Action Blackout Load Pro f i le - With Operator Action

1 M i n

Time Duration NormaT Reduction Total Tjme Duration Normal Reduction Total

1 (%lo (%i;? (E€%$ (M!n.) (Min.) (Min.) (Min.)

Load P r o f i l e Graph Data 0.00 604.40 1.00 604.40 1.00 271.80 30.00 271.80 30.00 271.80 90.00 271.80 90.00 0.00 239.00 0.00 239.00 0.00 240.00 0.00 240.00 0.00

228.38 228.38 228.38 228.38 228.38 228.38 360.38 360.38

0.00

228.38 228.38 203.18 203.18 203.18 203.18 332.21 332.21

0.00

S Curve Table For GC17 To GC 23 Cells Time Anps Per (Min) Pos. Plate

1 116.00 85.00

89 57.00 90 55.00 209 33.90 210 33.70 239 31.50 240 31.00

ss 84.00

Percent Increase In Deliverable Amp Hours During Blackout:

Uithout Operator Action= 122.94% With Operator Action= 101.58%

I V . BATTERY CELL S I Z I N G SHEETS

Data contained i n the load p r o f i l e and Wa curve tables i s automaticly read i n t o the fol lowing three c e l l s iz ing sheets.

Since the blackout evaluation assunes that the batter i s replaced three times instead o f the or ig ina l design basis o f tu0 times a t 50 year in terva ls 1.05 i s

during the 40 year l i f e t i m e (at 13 used as the Blackout Aging Factor.

year i nterva 1s)

Since the blackout evaluations w i l l support addit ional ca c i t y up t o the batter ies rated nunber o f pos i t i ve plates design margins are computed f o r each blackout evaluation. sheet as-being representat!ve o f the potent ia l for fu ture load Calculation Requried Posi t ive Plates and the rated pos i t i ve plages i s unusable due t o blackout constraints.

The m i n i m bKckout design margin j s - then used jn the normal battery c;ll Sizing rowth. Any addit ional capacity above the Normal c e l l s iz ing

125-VDC BATTERY S I Z I N G CALCULATIONS (NORMAL)

Louest Exp. Electrolyte Temp: Min. Cel l Voltage: Cel l Mfg- + P1ates:No. Cells: 60 F 1.84 VPC Exide 'GCT???: 1 1 59

(7) . (6) R uired Section Size

(1 1 (2) (3) (4) (5) Change i n Duratjon Time to.EnCa a c i t y (37(6) = Posi t ive Plates

Load Load of Period o f SectionT k in Rate Period (Amperes) (Amperes) (Minutes) (minutes) Amps/Pos.Pos. ValuNeg. Value

Section 1 - 1

Section 2 - 1 2

F i r s t Period Only

604.4 604.4 A l = A l - O =

F i r s t Two Periods A l = A 1 - 0 ~ 604.4 604.4

A2 = A2 - A 1 = 271.8 -332.6

- I f A2 i s reater than AI, go t o Section 2 M 1 = ? = M 1 =

Zl-= T = M1+M2 = M2= T = M 2 =

1 1 116 5.21 Section 1: Total 5.21

1 90 55 10.99 On1 I f A3 i s greater than A2, go t o Section 3

89 57 -5.84 89 Section 2:Sub-Total 10.99 -5.84

Total 5.15 - .- Random Equipment Load Only ( i f needed)

R AR= A R - O = M R = T = M R = 56.8 56.8 1 1 116 0.49

Max. Sect. Size 5.21

+ Uncorrected

Temperature

- - Size Random Sect.

Size 0.49 5.70 (Pos. Plates)

Uncorrected Correction Design Factor X Mar i n Size X - -

Size X Factor = Posi t ive Plates

Q.03 5.70 1.11 Needed Aging Required No.

6.52 1.25 8.14 Percent Unusable Capacity Due To Blackout= 25.96

I - _ _ _

Needed Size 6.52 (Pos. Plates)

-.

125-VDC BATTERY S I Z I N G CALCULATIONS (BLACKOUT WITHOUT OPERATOR ACTION)

Louest Exp. E lect ro ly te Temp: Min. Cel l Voltage: Cel l Mfg- + P1ates:No. Cells:

(7) 60 F 1.84 VPC Ex i de 'GCT???: 11 59

(1) (2) (3) (4) (5) (6) . . . . . - . . . . R uirefl'Secfion Size

Change in Duration Time to-EnCa ac i t y (33(6) - Posit ive Plates Load Load of Period of SectionT Rin Rate

Period (Amperes) (Amperes) (Minutes) (minutes) Arrps/Pos.Pos. ValuNeg. Value

Sect ion 1

Sect i on 1

2

Section 1

2

3

Random E R

1 -

2 -

3 -

iqui

F i r s t Period Only - I f A2 i s reater than A I , go t o Section 2 11L 1. a1

A I = A1 ;,! ; M l = , f M I 7 561 .O a", ."

' Sec!ion i: TOCAP 222 i - I f A3 i s greater than A2. go t o Section 3 F i r s t Two Periods On1

A1 = A I - 0 81 = T = Ml+M2 = 561.0 561.0 1 239 31.5

228.4 -332.6 238 238 33.7 A 2 = A 2 - A l = M2= T = M Z =

Section 2:Sub-Total Total

56i.n 5 ~ i . n 7 ~ n ?I

F i r s t Three Periods Only - I f A4 i s reater than A1 - A I - 0 - M I = T - MI+MP+M3 =

A3-g 360

_ - 17.81

-9.87 17.81 -9.87 7.94

A3, go t o Section 4

--.-- AZ-=-- A2 - A I = M2 = ' T = M2;Mj 728.4 -332.6 238 239 31.5 -10.56

.4 132.0 1 1 116 1.14 Section 3:Sub-Total 18.10 -9.42

Load Onlv ( i f needed)

A 3 - A 2 = M3= T = M 3 =

Total 8.68

Uncorrected

Temperature

+ - - Size Max. Sect. Random Sect.

Size Size 8.68 0.49 9.17 (Pos. Plates)

Uncorrected Correction Design Needed Size X Factor X Margin = Size

Size X Factor = Posit ive Plates

9.17 1.11 NCA 10.17 (Pos. Plates) Needed Aging Required No.

10.17 1 .os 10.68 Blackout Design Margin= 1.03

125-VDC BATTERY S I Z I N G CALCULATIONS (BLACKOUT W I T H OPERATOR ACTION)

Louest Exp. E lect ro ly te Temp:

Change i n

Period (Amperes) (Amperes)

60 F ( 1 ) (2) (3)

Load Load

Min. Cel l 1.84

(4) Durat !on

of Period (Minutes)

Voltage: Cell-Mfg: + P1ates:No. Cells:

Time to.EnCa ac i t y (33 (6 ) = Posit ive Plates of SectionT i i n Rate (minutes) Amps/Pos.Pos. ValuNeg. Value

VPC Exide GCT$?: 11 59 (7)

(6) R u i red Section Size (5)

i s greater than A l . go t o Section 2 Section 1 - F i r s t Period Only - I f A2 . - 1 A l = A l - 0 ~ M I = f = M 1 =

561.0 561.0 1 1 116 4.84 I: Total 4.84 ;ater than A2, go t o Section 3 -

-3.91 6.68 -3.91 2.77

n A3, go t o Section 4

Section ' Section 2 - F i r s t Two Periods On1 I f A3 i s grt

1 A I = A I - 0 = k l - = T = MI+ML

2 A 2 = A 2 - A l = M2= T = M 2 = 561.0 561.0 1 30 84 6.68

228.4 -332.6 29 29 85

Total Section 2:Sub-Total

reater thai Section 3 - F i r s t Three Perif is Only - I f A4 i s 1 A I = A I - 0 - M1 = T = MI+Mj+M3 = 2 A2 =. A2 - A I = M2 = T = M2+M3 = 3 A 3 = A 3 - A 2 = M3= T = M 3 =

561 0 561.0 239 31.5 17.81

228.4 -332.6 29 238 33.7 -9.87

203.2 -25.2 209 209 33.9 -0.74 Section 3:Sub-Total 17.81 -10.61

Total 7.20 Section 4 - F i r s t Three Periods Only - If A5 i s reater than A4, go t o Section 5

561.0 561.0 1 240 31.00 18.10

228.4 -332.6 29 239 31.50 -10.56

203.2 -25.2 209 210 33.70 -0.75

332.2 129.0 1 1 116.00 1.11 Section 3:Sub-Total 19.21 -11.31

Total 7.90

56.8 56.8 1 1 116.00 0.49

1 A I = A1 - 0 = M I = T = Ml+M%+M3+M4 = 2 A2 = A2 - A1 = M2 = T = M2+M3+M4 =

3 A3 = A3 - A2 = M3 = T = M3+M4 =

4 A 4 = A 4 - A 3 = M4= T = M 4 =

Random Equipment Load Only ( i f needed) R A R = A R - O = M R = T = M R =

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uncorrected + - - Size Max. Sect. Random Sect.

Size Size 7.90 0.49 8.39 (Pos. Plates)

Temperature Needed Size

Uncorrected Correction Design X Mar i n

NQA 9.99 (Pos. Plates) Size X Factor

Size X Factor = Posit ive Plates

8.39 1.19 Needed Aging Required No.

9.99 1.05 10.49

Blackout Design Margin= 1.05

997

700

600

500

- m 400

v f - C

300 F 3 U

200

1 0 0

0

600

500

400

200

1 0 0

0

600

500

400

200

1 0 0

0

Normal Load Profile Graph

I I 1 1 ' 1 I , ' , , , ,

0 40 80 120 1 6 0 200 240

Time (minutes)

Blackout Load Profile Graph (No Operator Action)

I 0 40 80 120 160 200 240

Time (minutes)

Blackout Load Profile Graph (With Operator k tion)

I I I I 1 I I I I I ,

0 40 80 120 1 60 200

Time (minutes)

998

I I