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GEI-44233 

INSPECTION 

At  the  time  of  installation,  the  relay  should  be  inspected  for  tarnished  contacts,  loose  screws,  or 

other 

imperfections. 

If  any  trouble  is  found,  it  should  be  corrected  in  the  manner  described  under 

MAINTENANCE. 

CAUTION: 

EVERY  CIRCUIT  IN  THE  DRAWOUT  CASE  HAS  AN  AUXILIARY  BRUSH.  IT  IS  ESPECIALLY  IMPORTANT  ON  CURRENT 

CIRCUITS  AND  OTHER  CIRCUITS  WITH  SHORTING  BARS  THAT  THE  AUXILIARY  BRUSH  BE  BENT  HIGH  ENOUGH  TO  ENGAGE  THE 
CONNECTING  PLUG  OR  TEST  PLUG  BEFORE  THE  MAIN  BRUSHES  DO. 

THIS  WILL  PREVENT  CT  SECONDARY  CIRCUITS  FROM  BEING 

OPENED. 

PERIODIC  CHECKS  AND  ROUTINE  MAINTENANCE 

In  view 

of  the  vital  role  of  protective  relays  in 

the  operation  of  a  power  system,  it  is  important 

that  a 

periodic  test  program  be  followed. 

It  is  recognized  that  the  interval  between  periodic  checks 

will 

vary  depending 

upon 

environment,  type  of  relay  and  the  user's  experience  with  periodic  testing. 

Until  the 

user 

has  accumulated  enough  experience  to  select  the  test  interval  best  suited  to  his  individual  require­

ments,  it  is 

suggested  that  the  points  listed  below  be  checked  at  an  interval 

of 

once  a  year.* 

These  tests  are  intended  to  ensure  that  the  relays  have 

not 

de

v

ia

te

d  from  their  original  settings. 

If 

deviations  are  en

c

ounte

r

e

d,  the  relay  must  be  retested  and  serviced  as  d

es

c

r

ib

e

in 

this  manual. 

TIME-OVERCURRENT 

UNIT 

Perform  the  tests  described  in  the 

ACCEPTANCE 

TEST  section.  The  tap  that  i

s  in 

service 

may  be  used 

instead  of  the  lowest  tap;  this  will  not  change 

the 

test  limits. 

INSTANTANEOUS 

UNIT 

Check  that  the  instantaneous  unit 

picks  up  at  the  desired  current  level, 

as 

o

ut

l

i

ne

in  the  ACCEPTANCE 

TEST  section. 

If  the  unit  is  not  set  at  the  minimum 

calibration  mark, 

pickup  should  be 

within 

+1 5 

pe

rc

en

of 

the  mark  for  which  it  is  set. 

HIGH  DROPOUT 

INSTANTANEOUS 

UNIT 

Check  pickup  and  dropout  current  to  the  limits  outlined  in  the 

ACCEPTANCE  TE

ST  section. 

TARGET  AND  SEAL-IN 

UNIT 

Check  pickup  and  dropout  as  outlined  in  the  ACCEPTANCE  TEST  section. 

CONTACT  CLEANING 

For  cleaning  relay  contacts,  a  flexible  burnishing 

tool  should 

be  used.  This  consists  of  a  flexible 

strip  of  metal  with  an  etched-roughened  surface  resembling  in  effect  a  superfine  file.  The  polishing  action 

is  so  delicate  that  no  scratches  are  left,  yet  it 

will 

clean  off  any  corrosion  thoroughly  and 

r

apidl

y

Its 

flexibility  ensures  the  cleaning  of  the  actual  points  of  contact. 

Do  not  use  knives,  files,  abrasive  paper 

or  cloth  of  any  kind  to  clean  relay  contacts. 

SYSTEM  TEST 

Although  this  instruction  book  is  primarily 

written  to  check  and  set  the  lAC 

rel

ay

,  overall  functional 

tests  to  check  tne  system  operation  are  recommended  at  intervals  based  on  the  customer's  experience. 

SERVICING  AND  ADJUSTMENTS 

TIME-OVERCURRENT  UNIT 

If 

it  is  found  during  installation  or 

p

e

r

iodi

c  testing 

that 

t

h

e  time-overcurrent  unit  is  out  of  limits, 

the  unit  may  be  recalibrated  a

f

ol

l

o

w

s

Rotate  time  dial 

to 

No.  0 

time-dial  setting  and  check  by  means  of  a 

lamp  that 

the  contacts  just  close. 

Where  the  contacts 

just 

close 

can  be 

adjusted  by 

running  t

he  stationary  contact  brush  in  or  out  by 

means 

of 

its  adjusting  screw.  This 

s

c

rew 

s

ho

u

l

b

h

e

l

d  secu

rely 

in  its  sup

p

or

t

With  the  contacts  just  closing  at 

No.  0 

time  setting,  there  should 

be 

sufficient  gap  between  the 

stationary  contact  brush  and 

its  metal  b

a

c

k

in

strip 

to  ensure  approximately  l/32 

inch 

wipe. 

Indicates  revision 

www 

. ElectricalPartManuals 

. com 

Summary of Contents for IAC66K

Page 1: ...INSTRUCTIONS TIME OVERCURRENT RELAYS TY PE IAC66K GENERAL fj ELECTRIC GEI 44233 F Supersedes GEI 44233 E w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 2: ...ON 7 LOCATION 7 MOUNTING 7 CONNECTIONS 7 INSPECTION 8 PERIODIC CHECKS AND ROUTINE MAINTENANCE 8 TIME OVERCURRENT UNIT 8 INSTANTANEOUS UNIT 8 HIGH DROPOUT INSTANTANEOUS UNIT 8 TARGET AND SEAL IN UNIT 8 CONTACT CLEANING 8 SYSTEM TEST 8 SERVICING AND ADJUSTMENTS 8 TIME OVERCURRENT UNIT 8 PICKUP TESTS 9 TIME SETTING 9 STANDARD INSTANTANEOUS UNIT 9 HIGH DROPOUT INSTANTANEOUS UNIT 9 TARGET AND SEAL IN U...

Page 3: ...A 50 IOC B UNIT UNIT 0 8 1 7 l 2 10 40 2 6 1 4 2 6 1 5 3 10 40 4 12 l B 4 3 2 5 5 20 80 4 12 1 8 4 3 2 6 20 80 4 12 2 9 5 0 4 8 20 80 4 12 When adjusted as shown above the relay operates as follows 1 For overloads the 51 unit times out picking up external auxiliary 51X which rings the alarm bell 2 For locked rotor the 50 IOC B unit will pick up instantaneously and the 51 unit will pick up with tim...

Page 4: ...coils of the protective relay The standard instantaneous unit ranges available are 4 16 10 40 20 80 and 40 160 amperes The high dropout instantaneous unit ranges available are 2 6 4 12 10 30 and 20 60 amperes CHARACTERISTICS The time current characteristics for the Type IAC66K relay induction unit are shown in Fig 1 Fig 2 shows the time current characteristics of the standard instant eous unit The...

Page 5: ...hes up and remains exposed until released by pressing a button beneath the l ower l eft corner of the cover The standard instantaneous unit is a small instantaneous hinge type unit mounted on the right front side of the induction unit Its contacts are normall y connected in parallel with the contacts of the main unit Its coil is connected in series with the operating coil of the main unit When the...

Page 6: ...es are operated by hand and should unlatch when the target release lever is operated 5 Make sure that the fingers and shorting bars agree with the internal connections diagram CAUTION EVERY CIRCUIT IN THE DRAWOUT CASE HAS AN AUXILIARY BRUSH IT IS ESPECIALLY IMPORTANT ON CURRENT CIRCUITS AND OTHER CIRCUITS WITrl SHORTING BARS THAT THE AUXILIARY BRUSH BE BENT HIGH ENOUGH TO ENGAGE THE CONNECTING PLU...

Page 7: ...meplate Dropout current should be at least 80 percent of the minimum rating on the nameplate TARGET AND SEAL IN UNIT PICKUP AND DROPOUT TEST 1 Connect relay studs l and 2 see internal connections diagram to a DC source ammeter and load box so that the current can be controlled over a range of 0 1 to 2 0 amperes 2 Turn the time dial to the ZERO TIME DIAL position 3 Increase the current slowly until...

Page 8: ...e ACCEPTANCE TEST section If the unit is not set at the minimum calibration mark pickup should be within 1 5 percent of the mark for which it is set HIGH DROPOUT INSTANTANEOUS UNIT Check pickup and dropout current to the limits outlined in the ACCEPTANCE TEST section TARGET AND SEAL IN UNIT Check pickup and dropout as outlined in the ACCEPTANCE TEST section CONTACT CLEANING For cleaning relay cont...

Page 9: ...iece loosen the locknut and turn it up or down and then tighten in position The contacts should be adjusted to make at about the same time and to have approximately 1 32 inch wipe This adjustment can be made by loosening the screws holding the stationary contacts and moving the contacts up or down as required HIGH DROPOUT INSTANTANEOUS UNIT The high dropout instantaneous unit is similar to the sta...

Page 10: ...ent the right hand stationary contact from getting out of adjust ment Screws should not be in both taps at the same time RENEWAL PARTS It is recommended that sufficient quantities of renewal parts be carried in stock to enable the prompt replacement of any that are worn broken or damaged When ordering renewal parts address the nearest Sales Office of the General Electric Company specify quantity r...

Page 11: ...I I I 7 I 110 GEI 44233 20 30 40 5GI070101DB 10 9 8 7 1 6 111 5 c r 4 3 2 I 0 E I I IZ 2f 30 50 10 70 10 luj MULTIPLES OF RELAY TAP SETTING I I 111111 1 I 1 101 1 1 0 H 21 10 I I I 1 1 FIG 1 088880273 0 Time current Characteristics of Type IAC66K Relay 11 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 12: ... 025 r ocs r 4 f 1 5 2 3 _ CJIWTIII TittlE PIOit Jli_ lfTTI r t 1 11 i 1 I I t i j r t 1 t FIG 2 0208A8695 1 Time current Characteristic of Standard Hi Seismic Instantaneous Unit 12 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 13: ...EOUS INDUCTION STANDARD HI DROPOUT r t 1 n j t l I l fl l 1 3 9 I 2 6 10 SHORT FINGER FIG 3 402A903 l Internal Connections Diagram for Type IAC66K Relay Front View 13 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 14: ...AUXILIARY RELAY 50 IOC A NORMAL DROPOUT INSTANTANEOUS OVERCURRENT UNIT 52 POWERCTRCU IT BREAKER W IOG 8 HIGH DROPOUT INSTANTANEOUS OVERCURRENT UNIT 52 a AUXILIARY CONTACT CLOSED WHEN CIRCUI T BREAKER IS CLOSED TC TRIP COIL FIG 4 104A8568 3 Typical External Connections for Motor Pr otection Using Type IAC66K Relays 14 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 15: ...NG PLUG MAIN BRUSH AUXILIARY BRUSH CONNECTING BLOCK TERMINAL BLOCK SHORTING BAR JOTE AFTER ENGAGING AUXILIARY BR USH CONNECTING PLUG TRAVELS 1 4 INCH BEFORE ENGAGING THE MAIN BRUSH ON THE TERMINAL BLOCK FIG 6 8025039 Cross Section of Drawout Case Showing Position of Auxil iary Brush 15 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 16: ... 223MM ___ __ ____ __ 711 VIEW SHOWiNG 18MM ASSEMEl f OF HARlWARE FOR SURFACE MTG ON STEEL PAN EL5 PANEL ORtL UNG F SEMI FWSH MOUNTIN tFRONT VIEW DRILL 10 HOLES 19MM 6 80 11 58 PANEL ORILllMG FOR SJRFAC CUNTING TFRO T VIEW FIG 7 K 6209271 6 Outline and Panel Drilling for the Type IAC66K Relays GENERAL ELECTRIC CO POWER SYSTEMS MANAGEMENT BUSINESS DEPT MALVERN PA 1935 i w w w E l e c t r i c a l P ...

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