ML19275A058

Responds to 790620,0816 & 21 Ltrs Re Degraded Grid Voltage. Forwards Undervoltage Relays & Test Plugs for Drawout Relays & Meters by GE & Table 1, ANO-1 Running Loads Upon Full House Transfer to ST 1.

ML19275A058
Person / Time
Site:	Arkansas Nuclear
Issue date:	08/24/1979
From:	Trimble D ARKANSAS POWER & LIGHT CO.
To:	Reid R Office of Nuclear Reactor Regulation
References
1-089-13, 1-89-13, NUDOCS 7908300670
Download: ML19275A058 (22)

Text

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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 (501) 371-4000 August 24, 1979 -

1-089-13 Di re ct or of Nu clea r React or Reg ula tion ATTN: Mr. R obe rt W. Reid, Chief Ope rating React ors B ra nch #4 U. S. Nu clea r Reg ula t o ry C ommis s i o n Wa shingt on, D. C. 20555 S ub j e ct : A rka ns a s Nu cle a r One-Unit 1 Docket No. 50-313 Li ce ns e N o. DPR-51 Deg rad e d Grid Voltage (File: 1510)

Gentlemen:

The f ollowi ng is p r ovid e d t o:

1) C om p l e t e ou r re s p o ns e t o ou r Ju ne 20, 1979, letter

2) Re s p o nd to your le t te r Augus t 16, 1979

3) Respond to our telecon of August 21, 1979.

Pa rt 1. Response t o June 20, 1979, lette r Item 7.

F o r e a ch Se ction of IEEE 279, d e sc ribe h ow the p r op os ed u nd e r-voltage p rotection modifica tion c om p lie s with the c rit e ria .

R e s p o ns e :

The f ol l owi ng briefly d e sc ribe s h ow ou r Mills t one Modifi-cations as p rop osed to you in ou r Augus t 23, 1978, le t te r c onf o rm to the requi reme nt s of each Se etion of IEEE 279.

a. Ge ne ral Functional Requirements - The devices and equip-ment used a re qualified f or Class lE application and the pe rf ormance of the devices is highly reliable. The system is d e sig ned s o that the p r ot e c t iv e action is a u t o-matically initiated as the system re a ch e s p re se nt levels.

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1-089-13 Mr. Rob e rt W. Reid August 24, 1979

b. Single Fa ilu re C rit e ri on - The two load g roups a re pro-vided with red u nd a nt protective actuation c ont rol systems. Also, wi ri ng f or ea ch of the two c ont rol gystems is routed in sepa rate Class 1E raceways.

c. Quality of C omp one nt s and Modules The devices used for the two p rotection sys tems a re qualified f or Class lE application.

d. Equipment Q u ali f i ca t i ons The available type test data f or Class 1E c omp one nt s qualifications c onf i rms the req ui red sa tis f a ct o ry pe rf o rma nce of the p r ote ction equipment unde r the e nv i r o nme nt al conditions stated in Se ction 3. 7 & 3.9 of the IEEE-279-1971.

e. Channel Int eg ri t y The p rot e c t ive systems p rop osed have been desig ned f or f ail safe ope rati on. The devices and ci rcuit ry used a re Class lE and the re f ore shall rema i n ope ra ti onal unde r ext reme e nvi r onme nt al , e ne rgy supply a nd accident conditions.

f. Channel Independence The equipme nt , devices, a nd race-ways for one Class 1E system a re i nd e p e nd e nt and physically sepa ra ted f r om the othe r sys tem . The circuits for the two Class 1E protective systems a re also routed in sepa ra te raceways.

g. C ont rol a nd P r ote ct i on Sys tem Int e ra ct i ons All the equipment is c ons id e red pa rt of the protection system which is d e sig ned t o me e t the requi reme nt s of IEEE 279 with the exception of the RCP sta rting bypass initiation which is a non-Class lE system. F or mo re detail, please re f e r t o a nswe r t o Question 6.

h. Is ola ti on Devices Is ola tion devi ces a re not used as the systems a re c om p le t e l y Class lE.

i. Single Ra nd om Fa il u re a nd Multiple Fa il u re s Re sult ing f r om a C redible Single Event - The re a re no single f ailure points as the systems a re c om p le t el y Class lE, s e p a ra t e ,

and red u nd a nt .

j. De riva t i on of System Inputs - The u nd e rv ol t ag e relays p r o-posed at the 480'/ ESF buses will mea s u re the system de-g rad ed c ondi t 1 ons di re ctl y and initiate the p r ote ct iv e action at the system level within its repective load group.

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1-089-13 Mr. Rob e rt W. Reid August 24 1979

k. Capability f or Se nc or Ch e ck s Ihe 92% unde r v oltage relays have been p r ovid ed with f u nct i onal test switches. Pe riodic t e s t i ng will e nsu re the se ns o rs '

op e ra ti onal capability.

1. Capability f or Test and C a lib ra t i o n The system has the capability f or testing. Calibration of devices is discussed unde r item 9. c.

m. Cha nnel Bypass or Rem oval f r om Ope ra tion As explained in the reply t e Ques tion 3, of ou r let te r of July 12, 1979, systems have the capability t o be tested in se rvice without initiating a p rot e ct ive action at the system level a nd also continue t o mo c + the single f ailu re c rite rion .

n. Ope ra ting By; Pass The p r ot e c t iv e action of the two systems can ue bypassed manually d u ri ng s ta rting of the RCP m o t o rs . The ope rating bypasses a re Class lE.

o. Indication of By-passes The by-passes will be ala rmed in the C o n t r ol R o om ,

p. Access t o Mea ns f o r By Passing Manuui bypass of p r o-tective action is p rovid e d th rough test switches. The access to the test swi t ch e s will be u nde r the admin-is t ra t ive c ont rol of the Shift S up e rvis o r . The RCP bypass will u nde r admi nis t ra tive c ont rol of the Shift S upe rvis or.

q. Multiple Set Points The p r ot e ct iv e devices a re set at one set point only.

r. C om p le t i on of Protective Action Once It Is Initiated Once the protective action has been initiated the offsite s ou rce is a ut oma t ical ly disc onne ct ed and the on-site source (Diesel) is made available within a sh o rt time.

The p r ot e c t iv e action will go t o c om p l e t i o n once initiated.

s. Manual Initiation - Manual c ont r ol is provided on each of the two b reake rs f or c onnecting or disc onnecting the off-site a nd on-site s ou rce s to the a uxilia ry p owe r sys t ems.

Ma nual initia tion .requi res ope ra tion of a minimum numbe r of switches.

t. Access to Set Point Ad j us tme nt Calib ration and Test P oint s Access to Set Point Adjustment, Calib ra tion a nd Te s t Points is c ont r ol le d Adminis t ra tively u nde r the Shift Sup e rvis o r a nd is limited to qualified pe rs onnel .

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1-089-13

- M r. R ob e rt W. Re id August 24, 1979

u. Identification of Protective Action - The b re ake rs for the of f-site and on-site s ou rces have close a nd t rip indica-tions in the c ont r ol r o om to identify the protective actions.

v. Inf o rma ti on Re ad Out - Sufficient monit o ring has been p r ov id e d in the c ont r ol r o om which will enable the op e ra +. o r t o kn ow the de te rio ra ting c ondi t i ons of the s y s t eens .

w. System Repair - Pe riodic t e s t i ng of the system will en-su re the detection of the malfunction of c omp one nt s or m od ule s . Plug in type of c om p o ne nt s a re used wh e re possible s o that the faulty units can be replaced, re-p a i red or adj us ted exp edi ti ous l y . Al s o the system pro-tective action is designed such that the f ailu re of one u nde r v ol t age relay will not disable protective action.

x. Identification - The equipment and wi ri ng of the cwo p r o-tective systems have been id e ntif ied as red a nd g ree n channels.

Item 9c.

The ANO-1 a nal y s is assumed that p r ot e c t iv e action would be executed at ( o r ab ove) the cal cula t ed valve of 92% (Mot or-base) v ol t ag e . Indicate: (c) a l l owa n ce (above 92%) used to a c c omm od a t e d rif t s . Describe the basis f or de te rmining these all owa nce s. De s c ribe the bases f o r d e t e rmi ning the n om i n a l setpoint which provides maximum protection consis-t e nt wi th minimum spu riris shedding f r om the pe rf e rred p owe r s ou rce (i.e., ele ct ric g rid) .

Re s p o ns e :

The 4 6 0 u nd e rv ol t age relays a re s olid state relays set to t rip at a specific v olt age . The physical ina ccu ra cie s of the relay a re within the e rror ba nd of calibrated test equipme nt and a re the re f ore indisce rnible . Upon installation of the relay, it will be calibrated us i ng ins t rume nt s that a re cali-b ra t ed t ra cea b le to the National Bu re a u of S t a nd a rd s .

To date, no inf o rma tion exis t s on possible d rif t of the relay.

Upon installation, the . relay will be calib ra t ed at the f i rs t refueling outage f ol l owi ng ins t alla ti on. Allowa nce f or d rif t will be made at that time if applicable. D rif t is expected to be mi nim al if a ny .

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1-089-13 Mr. Robe rt W. Re id August 24, 1979 Pa rt 2 NRC August 16, 1979, Letter Item 2 P r ovid e the 480 volt a nd 416 0 v ol t AC ele ct rical schematics sh owing the p rop osed d eg rad ed v olt age p rotection system (b oth levels of p r ote ct i on) .

Response

The req u e s t ed sch ema tics a re s h ow n on d rawi ng E-99 sheet 1 Rev. 8-1 which was attached to ou r lette r July 12, 1979, as pa rt of our response t o I t em 6.

Item 3 The p r op os ed u n d e rv ol t a g e relays will have test plug capability.

Describe the test plugs, their function, a nd their ef f ect on the relay. How is the test p e rf o rme d a nd s pe ci f i cal ly what is the function which is tested? Provide a schematic which ill us t ra te s the f u nct i on of the test plug on the relay.

Re s p ons e :

At tached is ins t ruction ma nual G.E H-1768A s h owi ng the connect-ing plugs. A description of the test plug is sh own by the attached publication gel- 2 53 7 2. When the connecting plug is re m ov e d and a test plug is inse rted in its place, all relay points a re accessed, both the relay side a nd the s ou rce side, since each side is brought to a se pa ra te t e rmi nal on the test plug.

Since this relay is an u nd e rv ol t ag e relay with contact cl osu re output set to close at a specific set point, the relay contact cl osu re can be ve rified at the set point wi th out execution of the desired final action.

Item 4 a) We i n t e rp r e t your response to say that a calib ra t i on f ol l owe d by a functional test will be c ond u c t e d p ri o r to i ni t i al ope ra ti on of this system and d u ring each re f u eli ng outage the rea f te r. While we believe this test int e rv al is appro-priate f o r calib ration pu rp oses, op e rab ili ty sh ould be ve rified by pe rf o rming a functional test more of ten, e.g.,

monthly o r qua rte rly. Propose a suitable test i nt e rval for functional testing.

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1-089-13 Mr. R ob e r t W. Reid August 24, 1979 b) We specifically requested a description cf the test pro-g ram which would ve rif y ( once prior to initial op e ra t i on of the protection system) that no unacceptable voltage would be applied to ESF equipment when the g rid is at the defined "mi nim um- n o rmal" level. Describe the test

- og ram ,

c) We a re ' once rned about the ad equ a cy of the v ol t ag e applied to ESF equipment during the s ta rt ing of la rge non-Class lE m ot o rs , su ch as react or c oola nt pump mot ors. This is a maj or conce rn. You" analysis indicates that the l owe s t acceptable v ol t ag e is 92% f o r a n eigh t-s e c ond d u ra ti on.

Du ring the s ta rting of la rge motors, you have stated that the v ol t age falls bel ow 92% and stays for longe r tha n eigh t seconds. P r ov id e the valves of these lowe r v oltages a nd d u ra t i on for the s ta rting of each la rge n on-l E mot o r (u nde r a p p rop ria t e plant and g rid c onditi ons) . Explain why voltage levels b e l ow you r minimum v ol t a g e acceptance c rite rion should be c ons id e red acceptable. Please note that the voltages when s ta rting la rge mot o rs must be d e t e rmi ne d to be accept-able ( on a n ap p rop ria te basis) be f ore one c onside rs the accept-ability of a de s ig n f e a tu re that would bypass the deg rad ed voltate protection during such sta rtings .

Re s p o ns e :

a) We again p r op ose our re s p o ns e to this item in ou r le t te r of July 12, 1979, as ap p r op ria te . This is based on Te ch ni cal Specification requi reme nt s for othe r safety systems. ANO-1 Technical Specifications re qu i re Functional Testing of on-sata p owe r s ou rces and ECCS once per 18 months. We c not conside r the p rop os ed Millstone M od i f i c a t i o ns t o be of g reate r saf ety im p o rt a nc e than the a b ov e systems and believe testing f requencies consistent with these above systems is a p p r op ria t e .

A testing f reque ncy of once per 18 months is consistent -

with the requi rem e nt s of NRC Position 3 t ra nsmit ted to us by Mr. D. K. Davis' le t te r of June 3, 1977.

b) After i ns t al la t i on, the system will be dem ons t rated ope-ra b le by a functional test as de s c rib e d in ou r le t te r of July 12, 1979, response t o Item 4a.

c) Y ou r inte rp retation of the 92% bus voltage c rit e ria is not c o rre ct in that it is not mi nim um al l owa b le in all cases.

Ap p e nd ix 1 page 5 of ou r lette r of August 23, 1978, identi-s fies 90% c omp one nt v ol t ag e (92% bus v ol t ag e ) as limiting f or continu ous ope ra ti on but notes that "Sa f e t y- re la t ed

~

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1-089-13 Mr. Robe rt W. Re id August 24, 1979 mot o rs we re designed to p rovid e full load torque d u ri ng m om e nt a ry dip t o 75% of rated v ol t ag e wh e n othe r mot o rs' a c ce le ra te on the system. On that same page it states that "Du ri ng la rge mot or s + a rting , v ol t ag e s at the 4160V ESF busses we re ma rgina }[, not unacceptable. The voltage dips on the safety rela ted busses do not exceed 75% of ra + ? d voltage d u ri ng s ta rting of React or Coola nt Pumps.

Th e re f o re, the v ol t ag e dips due t o RCPs s ta rting a re within accepta nce c ri t e ria .

H oweve r, in a situa tion wh e re safety systems would be re-quired to op e ra t e (e.g., the potential f or an accident e xi s t s) , the RCPs would be ru n ni ng . In addition, IE or f or s ome t ime af te r the a ccide nt . We, the re f o re , p rop os e deletion of the a u t oma t i c by-pass of the u nd e rv ol t ag e relays as the RCPs will not be used d u ri ng the time f rame safety equipme nt is requ i re d .

The mag ni tude of the v ol t ag e dip due t o RCP s t a rt i ng is with-in the acceptance c rite ria for the safety equipment. H oweve r, the length of the v ol t age dip may exceed 8 se c onds , the re f o re ,

as RCPs must be s ta rt ed d u ri ng normal plant s ta rt up and may be resta rted at s om e belated time f ol l owi ng a n a c cid e nt , we p r o-pose installation of a manual by pass of the u nd e rv ol t age relays f or RCP s ta rting t o av oid spu rious t rips. This by pass will be class lE, Adminis t ra tively c ont r olled , and will a l a rm in the C o nt r ol R o om wh e n a ctua ted .

Item 5 Submittal V-2 A a nd V-3 A s h ow s mot or base v ol t ag e on 4160V bus highe r tha n designed maximum 110% a nd that on 480V bus as ma rgi nal . Fu rthe r, if t ra ns f o rme r se c ond a ry v ol t ag e gain (due t o highe r applied v oltage (22kv) on l owe r ra t e d (21.5kv) p rima ry wi ndi nf s ) is added to the bus v ol t ag e s , the result will be unacceptably highe r v olt ages on both 4160 and 480V equipment.

The submittal fu rthe r i nd i ca t e s that you r assumed no load con-dition includes 25% of the t ra ns f o rme r capacity as running load on 4 80V bus a nd 1.885 MVA o n 416 0V bus. You a re requested to justify 1.0 PU tap u nde r the a b ove mentioned concerns. Also p r ovid e the a nal y s is that gives acceptable v ol t ag e s on Class 1E equipment f or maximum g rid voltage and a realistic no load c ondi t i on (su ch as 5% or less of the t ra ns f o rme r capacity as 480V running load).

Re s p o ns e :

As noted, cases V-2A a nd V-3 A d o sh ow bus v ol t ag e s slightly a b ov e 1.1 P.U. However, the bus v ol t age s do not take int o c ons id e ra tion the v ol t ag e d r op s f o rm the bus to the actual c omp one nt s . Wh e n these voltage d rop s a re taken into c ons id e ra-ton, the ove r excita tion is mi nimal .

2033 023

1-089-13 Mr. Rob e rt W. Re id 8 August 24, 1979 In addition, the a b ov e 2 cases we re p r ov id e d in re s p ons e to a specific question cnd a re not re p re s e nt a t iv e of as v ol t- ,

ages safety equipment would eve r expe rience. These cases assume essentially no load on the busses. Du ring the modes of which safety systems a re required (e.g. M od e s 1, 2, 3, &

4), the re must be sig nif ica nt othe r pla nt loads on the busses f or the plant t o be in that M od e . O nl y in the case of a loss of of-fsite p owe r (in Modes 1, 2, 3 a nd 4) would the re be no non-safety loads running and in this case, safety loads would be p owe red f r om the Diesel Ge ne ra t o rs .

The re f ore , we conclude that the safety systems will not expe rie nce a ny ove r ex cita ti ons.

Rega rdi ng you r re f e re c ne t o t ra ns f o rme r to t ra ns f o rme r s e c onda ry gain due t o applied v ol t ag e of 22kv on t ra ns-f o rme r winding of 21.5 kv. This gain was taken int o a c-c ou nt in the c om p u t a t i o n a nd a p pe a rs as a tap 0.9'73 on the top right c o rne r of the case.

Item 6 Our review of the bypass ci rcui t for the s ta rting of la rge m ot o rs has de t e rmined that this single bypass is a single f ailu re point for ope ration of ESF equipme nt. This is a major concern. Each la rge mot or has a single time delay device. (This t ime r d oe s have two output c ont ra ct s wh i ch ope ra t e in a s e p a ra t e schemes to bypass the d eg raded v olt-age protection in both divisions of ele ct ric p owe r) .

H oweve r, the postulated f ailu re of the time r me chanism itself f o r a ny su ch mot or can result in the loss of v ol t ag e protection in both ele ct rical divisions. This single f ailu re p o t e nt ial must be delineated, possibly by using two time r me chanisms pe r mot or.

See ou r c omme nt ea rlie r rega rdi ng Item 4c.

Response: .

As discussed in ou r re s p o ns e t o It em 4 c ab ove , we p rop ose deletion of the aut oma tic b ypas s. The p rop os e d manual bypass will be Class lE a nd re d u nda nt .

Item 8 Your re s p o ns e dated July 12, 1979, indicated that load ahedding of essential loads was p rop osed only when the s ta tion auxilia ries a re supplied p owe r f r om s ta rt up t ra ns-f o rme r N o . 2 (ST 2). No load shedding would be applied to s ta rt up t ra ns f o rme r N o. 1 (ST 1) u nde r the same c ond i t i ons .

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1-089-13 Mr. Rob e rt W. Reid 9 August 24, 1979 Y ou r Augus t 23, 1978 analysis and all our subsequent c om -

mu ni ca ti ons have indicated that wh e n ope ra ting on ST-1 d u ri ng

" a b n o rm a l " c ond i t i ons , shedding of non essential loads was essential t o maintain accep table v ol t ag e . Expla'r this ch a ng e .

Sh ow why load shedding is not needed f o r S T-1.

Re s p o ns e :

D u ring c onve rs a t i ons with the staff in May, 1979, it was ag reed that the initial g rid c ond i t i ons assumed in our submittal of Augus t 23, 1978, we re ov e rl y res t rict ive a nd c onse rva t ive . We p rop osed new c o nd i t i ons that we re more realistic wh i ch would result in a nal ys es m o re c ons i s t e nt with NRC re qui reme nt s . These new a s s ump t i ons we re ag re ed t o by the Staff and we re t ra nsmi t ted t o you by ou r le t te r of May 21, 1979, along with new analyses.

Due to the ov e r c ons e rva t ism in the August 23, 1978, sub-mittal, it was ne ce s sa ry to shed loads on ST-1 t o a s su re adequate v ol t age . H owev e r, u nde r the m o re re al i s t i c (yet still v e ry c ons e rva t ive) a s sump t i ons of our May 21, 1979, le t te r, a nal y s e s indicate that load sh ed di ng up on fast t ra ns f e r to ST1 is no longe r ne ce s s a ry . Load shedding upon fast t ra ns f e r to ST 2 is s t il l ne c e s s a ry .

Item 9 As you have indicated, your re s p o ns e is not c om p l e t e . You have c ommi t t ed to p r ov id i ng inf orma tion on the set points of the u nde rv ol t age rel ay s . P r ovid e the inf o rma t i on or a schedule for providing the i nf o rma tion.

Ou r c once rn he re is a p r ope r s tack up of the t ole ra nce s in the system including the i na c cu ra cie s of ins t rumentation in ad j us t i n; the set points t o assu re that the v ol t ag e applied t o ESF equipment is not unacceptable. In you r dis cussion display su ch t ole ra nces a nd e rror ba nds a nd their stack up t o as su re that the v olt age applied to the ESF equipment is -

n ot unacceptable.

Anothe r conce rn is that, after c ons id e ring the buildup of ina c cu ra cie s , etc., the nominal setpoint sh ould not be so h ig h as to cause the safety buses t o be s pu ri ously di s c on-nected f r om the p re f e rred p owe r s ou rce .

Re s p o ns e :

See ou r re s p o ns e t o it em 4a in Pa rt 1 of this le t te r.

Pa rt 3 Telecon on August 21, 1979 Item 1 - RCP Bypass 2033 025

1-089-13 Mr. Rob e rt W. Reid August 24, 1979

Response

See ou r re s p o ns e t o It ems 4 c a nd 6 of Pa rt 2 above. -

Item 2 - C omp le t e d a nswe rs t o NRC's le t te r of June 20, 1979, letter.

Response

See Pa rt 1 above.

Item 3 P r ovid e a listing of equipme nt that c om p r i s e the 4160V and 480V running load as s h ow n on Table 2 to AP&L's lette r of May 21, 1979.

Re s p ons e :

Table 1, a t t a ch e d , is a listing ef all running loads assumed in the ab ove analysis.

Ve ry t ruly y o u rs ,

,/

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p a, .o ('f. '-

. David G. Trimble Ma nage r, Li ce ns i ng DCT/JTE/ew At ta chme nt 2033 026 1

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the shaft as shown in F-g.1. This unit has its coil .o 82 pg in series and its contacts in parallel with the main e contacts suchthat whenthe main contacts close, the seal-in unit picks up and seals in. When the scal-in sn (\\M

. yg unit picks up, it raises a target into view which 3M3O latches up and remains exposed until released by 5

~e k pressing a button beneath the lower-left corner of \ \WD the cover, y\ (W N The r eIa ys a r e all mounted in single unit \ YDM-MDC- 5h double-end cases. The case has studs for external , s \ NN Q MI connections at both ends. The electrical connec- y N N

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3 tions between the r ela and the case are made ,h Yd inner and rwater blocks through stationary mold <

between which rests a removable connecting plug N 4 _

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9 which completes the circuits. blocks carry t!'e studs for thee external while the inne. blocks carry the terminals for the " "

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2 internal connections. The operating coil is con- ,

nected in parallel withboth the upper and the lower inner molded blocks while the trip circuit is con-nected in series with th es e blocks. In this way, Fig. 2 Time-voltage Curves For Relay Types insertion of either the upper or lower conmeting LAY 54E And IAV5 plug will energizethe operating coil but t he t rip circuit will not be completed until the second con- .

necting p1ug is inserted. For relays which have The Type IAV54F relay is similar to tne Type contacts closed when the relay is de energized but IAV54E relay e7 cept that it has a longer opera ing optn under normal operating conditions, the double time. The timecharacteristicsare shown in Fig.3.

eted ha The Type IAV54H relay is also similar to the to p before the trip circu t co Type IAV54F relay except that it has much longer minirnizing the possibility of

• n c o r r ? c t tripping operating time than either the e IAV54E or the when returning the relay to service after tests and Type IAV54F relays. The time e racteristics are inspection. shown in Fig. 4.

APPLIC ATION The Type IAV55C relay is similar to the Type TAV54E relay except that it has two circuit closing '

These relays are protective devices designed contacts.

to close trip or alarm circuitswheneverthe voltage The Type IAV55F relay is similar to the Type applied to their operating coils reaches some pre- IAV54F rela 7 except that it has two circuit closinK determined value. The f anctions are described in contacts.

greater detail in the following paragraphs, The Type IAV55H relay is similar to the Type O F ~R ATIN G C H AR ACTERISTIC S IAV54H relay except that it has two circuit closing The Type IAV54E relay has a single circult-closing contact which closes when the voltage is reduced to some predetermined value. Thus, the The Type IAV55J relay is similar to the Type contacts are closed at zero volta. This relay is a IAV55H relay except that it is provided with two time undervoltage relay with inverse time charac- separate seal-in units; one for each set of nor-teristics which are shown in Fig. 2. mally closed contacts.

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2033 029 .

Type IAV Undervoltage Relays GEH-1768 g RECEIVING, HANDLING AND STORAGE These relays, when not included as a part of a packing the relay in order that none of the parts control panel will beshipped in cartons designed to are injured or the adjustments disturbed.

protect t h em against damage. Immediately upon receipt of a relay, examine it for any damage sus-tained in transit. If 1nj u ry or damage resulting If the rela s are not to be installed 'mrnedi-from rough handlingis evident, file a damage claim ately,they shoufdbe storedin their originalcartons at once with the t r a n s p o r t a t i o n company and in a plae e that is free from moisture

• dust and mp not e nearestGeneral Electric Appa- metallic c h i p s. Foreign matter colle ted or the outside of the case mayfind its way inside when the cover is removedand causetrouble inthe operation ncasonable c a r e should be exercised in un- of the re'ay.

DESCRIPTION CASE This cradle is held firmly in the case with a latch at the top and the bottom and by a guide pin at the The case is suitable for eit her surface or back of the case. The cases and cradles are so semVlush panel m ounting and an assortment of constructed that the relay cannot be inserted in the hardware is provided for eit h er mounting. The case upside d ow n. The connecting plue, besides cover attaches to the ca s e and also carries the making the electrical connections between the re-reset mechanismwhen onels required. Each cover spective blocks of the readle and case, also locks screw has provision for a sealing wire. the latch in placa "'h'. cover which is fastened to the case by thumbscrews, holds the connecting plug The case has studs or screw connections at in place.

both ends or at t h e bottom only for the external connections. Th e electrical connections between To draw out the relay unit the cover is first the relay unitsand thecase studs are made through removed, and t h e plug drawn out. Shorting bars spring backed contact fingers mountedin stationary are providedin the case to shortthe current trans-molded inner and outer blocks between which nests former circuits. T h e latches are then released, a removable connecting plug which completes the and the r ela y unit can be easily drawn out. To

) circuits. The outer blocks, attached to the case replace the relay unit,the reverse order is followed.

have the studs for t he external connections, and the inner blocks have the terminals for the internal A separatetesting plugcan beinserted in place connections. e of the connecting plug to test the relay la place on the panel either from its ow n source of current The r clay mechanism is mounted in a steel and voltage, or from other sources. Or, the relay framework called the cradle and is a complete unit unit can bedrawn outand replacedby another which with all lead > being terminated at the inner block, has been tested in the laboratory.

INSTALLATION LOCATION ADJUSTMENTS The locationshould be cleanand dry, free from TARGET AND SEAL [-IN UNIT dust and excessive vibration, and well lighted to facilitatt inspection and testing. For trip coils operating on currents ranging from 0.2 up to 2 amperes at the minimum control

) MOUNTING voltage, set the target and seal-in tap plug in the 0.2 ampere tap.

The relay s hould be mounted on a vertical surface. The outline and panel drilling dimes sions The tap plug is t h e screw holding the right-are shown in Flg. I1. hand stationary c on t a e t of the seal-in unit. To change the tap setting, first remove the connecting CO N N ECT!O NS plugs. Th> 7 take a screw from the left-hand sta-tionary e ont a e t and place it in the desired t ap.

The internalconnection diagrims are shown in Next, remove the screw from t h e other tap, and Figs. 5 a nd 6. Typical external connections are place it in the left-hand contact. This procedure is shown in Fig. 7. necessary toprevent tne right-hand stationary con-tact from getting out of adjustment. Screws should One of the mounting studs or screws should be not be in both taps at the same time, as d c pickup ptimanently grounded by a conductor not less than will have a higher tap value, whereas a".: pickup g No.12 B &S gage copper wire or its equivalent. will be increased, u 90 no w m 2033 030 1

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INSTRUCTIONS GEI-25372B Surtestots gel.25372A TEST PLUGS FOR DRAWOUT RELAYS AND METERS Types X L A12 A and X L A13 A e o 203.5 031 POWER SYSTEMS MANAGEMENT DEPARTMENT GEN ER AL h ELECTRIC PHILADELPHlA, PA.

GE!-25372 Test Plugs for Drawout Relays and Meters

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TEST PLUGS g FOR DRAWOUT RELAYS AND METERS TYPE XLA .

APPLIC ATIO N not disturb the current transformer shorting ar-rangement. The diagonally staggered binding posts The Type XLA test plugs are used to test are numbered. Numbers one to ten, corresponding drawout relays and meters. The XLA12A enables to the relay stud connections, appes_r up-right when power to be applied to the relay from either a using this plug in the bottom of a relay, while g separate source or the source that feeds the equip- number eleven to twenty appear up-side down, ment. The XLA13A can only be used when a Because of its design, the XLA13 test plug cannot separate source of power is available. be inserted into the bottom of a relay with numbers one to ten up-side down. Thus, the contacts of the inserted plug will always be toward the relay.

XLA12A TESTING The XLAl2A test plug consists of a black H ne esung can be accomplished by re-and red Textolite* molding with twenty electrically m ng the rday caer and suWWng eh M separate contact fingers connected to ten con- plug for the connecting plug.

centric bmding posts. The ten contact fingers on XLA12A the black side are connected to the inside binding posts with the black thumb nuts and engage the Several pieces cf hardware are supplied with relay internal connections. The contact fingers this test plug (See Fig. ',). The U-shaped link is on the red side are connected to tb ouier binding used to make through connections, relay stud to posts with the red thumb nuts and et . age the equip- case terminals. The long, open end link is used to ment case stud connections. See Fig.1. The con-centric binding posts are numbered on the nameplate' short circuit any current transformers and any e and the correspondmg contact fingers are numbered on each side of the test plug. When using the test normally closed contacts. This 1.nk must be in-serted in the proper place under the red thumb nuts before the test plug is inserted in the unit.

plug in the bottom of the relay, numbers one to ten, corresponding to the relay studs, appear upright, Two sizes of corregated end links are provided so while numbers eleven to twenty are upside down. standard test clips can be used. These links are It is impossible, du.e to its construction, to insert also provided with a hole so that a secure bolted the plug into the bottom of a relay with numbers connection may be obtained.

one to ten up-side down. By the same token, Typical separate source test connections and numbers eleven to twenty will always appear in the up-right position when the plug is inserted in th' wiring diagram for TYPE LAC overcurren; relays top of a relay. are shown in Fig. 3.

Removable test links for through connection A c nventional representation of test con-test clips and short-circuiting clips are furnishe[1 nections used on wirmg diagrams is shown in with each test plug. See Fig. 4. Fig. 9. An outime of this plug is shown in Fig.11.

XLA13A XLA13A No external provisions need be made ' r short-h The XLA 13A test plug consists of a black Textolite* molding with ten electrically separate ing current transformer secondaries or a Jrmally closed contacts because the plug is so designed that contac ts. Each contact terminates at a separate the side away from the relay to be tested does not binding post. See Fig. 2. When the relay connecting come into contact with any of the connecting fingers plug is withdrawn any current transformer second- in the case. Power source connections can be artes will be short circuited by shorting bars in the secured to the studs of the plug by the black thumb case. The insertion of the XLA13A test plug does nuts.

• Reg. Trade-Mark of General Electric Company These instructions do no? purport to cove oII details or variations in equipment nor to provide for every possible contiorgency to be met in connection with ins'allation, operation or maintenance. Should further information be desired or should particular problems crise which ors not covered sufficiently for the purchaser's purposes, the matter should be referred to the General Electric Company.

033

GE!-25372 Test Plugs for Drawout Relays and Meters

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TEST-CLtP OR BOLTED SHORT-CIRCUITING LINK THROUGH CONNECTION LINK

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. Test Plugs for Drawout Relays and Meters GEI-25372

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,I ha j iJ y TIMER A ADJUSTAGLE RE SISTOR Fig. 5 Typical Separate Source Connections and Wiring Diagra.m for Testing an LAC Overcurrent Relay Using the XLAl5A Test Plug Typical separate source test connections and wiring diagram for Type IAC overcurrent relays sary hardware is packed in the individual carton.

are shown in Fig. 5.

Immediately upon receipt of the test plug, an A conventional representation of the XLA13A examination should be made for any damage sus-est plug connections used on wiring diagrar.1s is tained in transit. If injury or rough handling is shown in Fig.10 evident a damage claim should be filed at once with the transportation company and the nearest General An outline diagram of the XLA13A test plug is Electric Sales Office should be notified.

shown in Fig.12.

RENEWAL PARTS SHIPPING - UNPACKING Orders for renewal parts, should be addressed Type XLA test plugs are shipped in individual to the nearest Sales Office of the General Electric cartons which may be used for storage. All neces- Company, giving the name of part w .nted, quantity required and complete nameplate data.

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2033 035 Fig. 6 Accessory Links for the XLA Test Plugs 5

GEI-25372 Test Plugs for Drawout Relays and Meters BLACK THUMB NUT BLACK SIDE CONTACT-M ARKED RELAY CONNECTIONS FINGERS-l

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Fig. 9 Conventional Representation of XLAl2A Fig. 10 Conventional Representation of XLA13A Test Plug Connections Test Plug Connections

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S 2033 036

Test Plugs for Drawout Relays and Meters GEI-25372

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Fig. Il Outline of the XLAl2A Test Plug 9

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OUTLIN E

1. F..g. 2033 037 12 Outline of the XLAl3A Test Plug 7

. TABLE 1 ANO-: RUNNINC 10^ UPON FULL HOUSE TRANSFER TO ST 1 Centi.i R o om Chille r (2) -

Instrument Air (2)

S pe nt Fuel P o ol C oole r (2)

Se rvice Wa te r Pump (2)

Makeup Pump (2)

Auxilia ry L. O. Pump (1)

React or Building C oole r (2)

React or Building C oole r (2)

Relay R o om Unit Cl r. (2)

Inve rte r T ra ns . (2)

. Pipe Heat T ra ci ng (1)

B a t t e ry Cha rge r (2)

Inst. AC T ra ns f o rme r (2)

P re s s . 14 t rs. (2)

Inve rte r T rans. SW. (2)

B a t t e ry R o om Extinguisher Fan (2)

Di s ch a rge vlume Rad. Monit or (1)

Stack Rad. Monit or PP . (1)

P r im . Make up R o om (1)

ICW Rad. Mon. (2)

S e rvi c e H2O Rad. Monitor (2)

Au xilia ry Building Swit chgea r (1)

Inst. Ai r D rye r (1)

C omput e r Inve rte r (1)

Au xili a ry Building Ltg . (1)

Reactor Building Ltg. (1)

C ond e ns a t e Pumps (2)

Ci rcu la t i ng Wa te r (4)

Non-safety Load Ce nte rs (5) 2033 038