GE AKR-30 Series Maintenance Manual page 259

SECTIO N 1 4-MicroVersaTrip® Plus and MicroVersaTrip® PM Trip Units
1 4.6 NEUTRAL C UR RENT SENSORS
CAUTION: Neutral current sensors are requ i red for three­
phase, four-wire systems. When the trip unit is connected
to a three-phase, three-wire system, the neutral sensor
terminals are left open. Do not short any neural current
sensor termi nals in a three-phase, three-wire system, as
this could result in damage to or malfunction of the
electrical system.
Fig. 1 1 8 shows the neutral sensor. The neural sensor is
req uired when integral g round fault protection is used on
single phase-three wire or three phase-four wire systems.
It is inserted into the neutral cond u ctor and therefore is
separately mounted in the cable or bus compartment.
The outputs of the phase sensors and neutral sensor
are connected to a programmer circuit which sums these
values. The total value will remain zero as long as there is
no ground current flowing.
The neutral sensor is an electrical d u plicate of the phase
sensor. Therefore, when phase sensors are changed, the the plug that was removed , follow the appropriate setup
neutral sensor must be correspondingly be changed .
FIG. 1 1 8 TYPICAL NEUTRAL SENSOR
1 4.7 RATING PLUG REMOVAL AND RE­
PLACEMENT
CAUTION: Removal of the rating plug while the breaker
is carrying current reduces the breaker's current-carrying
capacity to approximately 25% of the current sensor
rating.
Interchangeable rating p lugs are removed with a Rating
Plug Extractor, Catalog No. TRTOOL. (Su itable equiva­
lents are commercially available as "integrated circuit
(DIP) extractors . ") G rasp the rating plug tabs with the
extractor and pull the plug out. Be sure to g rab the tabs
and not the front cover of the rati ng plug, or the plug may
be damaged .
Rejection featu res are provided on all rating plugs to
prevent appl icat ion mismatches. Never force a rating
plug into place. Refer to Table 1 6 to find the appropriate
rating plugs for each sensor rating and breaker frame.
If a replacement rating plug has a d ifferent rating than
procedure G EH -589 1 A to enter the new rati ng.
Do not attem pt to use a rating plug from a Spectra RMS
breaker or a MicroVersaTri p® P l us or M icroVersaTrip"'
PM Trip Unit.
TABLE 1 6
Sensor
Cat. No. Rating, Amps
TR48 1 50
TR48200
TR48225
400
TR48250
TR48300
TR48400
TR88300
TR88400
TR88450
TR88500
800
TR88600
TR88700
TR88800
TR1 68600
TR1 68800
TR1 681 000
1 600
TR1 681 1 00
TR 1 681 200
TR1 681 600
TR208750
TR208800
TR2081 000
TR208 1 200 2000
TR2081 500
TR2081 600
TR2082000
Plug Breaker
Rating Frames
1 50
200
225 AKR30 ,
250 AKR30H
300
400
300
400
AKR30,
450
AKR30H,
500
AKR50S,
600
AKR50H
700
800
600
800
1 000 AKR50 ,
1 1 00 AKR50H
1 200
1 600
750
800
1 000
1 200 AKRT50H
1 500
1 600
2000
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