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GEI-44233 

TIME-OVERCURRENT  UNIT 

With  the  tap  plug  in  the  minimum  position  and  the  time  dial  set  in  the  No.  1/2  position,  check  the 

current  required  to  just  close  the  contact.  It  should  be  within  +5  percent  of  the  minimum  pickup  shown  on 

the  tap  block. 

The  operating  time  from  the  Number  5  time-dial  setting  at  five  times  minimum  pickup  setting  should  be 

within  seven  percent  of  the  value  shown  in  Fig.  1. 

With  the 

time 

dial  at  No.  10  time  setting  and  the  tap  plug  in  the  lowest  tap,  apply  sufficient  current 

in  the  relay  to  definitely  close  the  contacts.  Reduce  the  current  to  75  percent  of  tap  value  and  the  disk 
should  reset  all  the  way  to  the  No.  10  dial-setting  position. 

STANDARD  INSTANTANEOUS  UNIT 

With  the  target  in  the  down  position,  check  the  pickup  at  the  minimum  calibration  mark  using  rated  fre­

quency.  The  pickup  current  should  be  within  �15  percent  of  the  minimum  rating  on  the  nameplate. 

HIGH  DROPOUT  INSTANTANEOUS  UNIT 

Set  the  unit  for  the  minimum  calibration  shown  by  the  nameplate  rating.  With  rated  frequency  applied, 

the  pickup  current  should  be  within  �15  percent  of  the  minimum  rating  on  the  nameplate. 

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  the  seal-in  unit  picks  up.  See  Table  VI. 

4. 

Move  the  time  dial  away  from  the  ZERO  TIME-DIAL  position;  the  seal-in  unit  should  remain  in  the 
picked  up  position. 

5.  Decrease  the  current  slowly  until  the  seal-in  unit  drops  out.  See  Table  VI. 

TABLE  VI 

TAP 

PICKUP 

PICKUP 

CURRENT 

CURRENT 

0.2 

0.15-0.195 

0.05  OR  MORE 

2.0 

1.50-1.95 

0.55  OR  MORE 

INSTALLATION 

LOCATION 

The  location  should  be  clean  and  dry,  free  from  dust  and  excessive  vibration,  and  well  lighted  to 

facilitate  inspection  and  testing. 

MOUNTING 

The  relay  should  be  mounted  on  a  vertical  surface.  The  outline  and  panel  diagram  is  shown 

in 

Fig.  7. 

CONNECTIONS 

The  internal  connection  diagram  is  shown  in  Fig.  3. 

A  typical  external  wiring  diagram  is  shown  in 

Fig.  4. 

One  of  the  mounting  studs  or  screws  should  be  permanently  grounded  by  a  conductor  not  less  than  No.  12 

B&S  gage  copper  wire  or  its  equivalent. 

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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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