GE AKR-30 Series Maintenance Manual page 252

SECTIO N 1 3-RMS-9
Since the neutral sensor is mounted separately from the
breaker, a d iscon nect means is required to connect its
output to the breaker. Fig. 86 shows the breaker and
equi pment mounted 4th wire secondary disconnect used
with the R MS-9 system .
1 3.2.1
R EPlACEMENT OF CURRENT SENSORS
Referring to Fig. 87 B , replacement of RMS-9 & Epic
MicroVersaTrip current sensors is accompl ished by the
same procedure as the M icroVersaTrip® current sensors.
1 3.3
FLUX SHIFTER TRIP DEVICE
T h e o n l y d iff e r e n c e b etween t h e R M S - 9/E p i c
M icroVersaTrip® and SST flux shifter trip devices i s the
solenoid winding. Refer to Section 1 0. 3 for details.
When replacing a RMS-9/Epic M icroVersaTrip@ flux
shifter, AMP extraction tool Cat. No. 455822-2 is required
to remove the socket leads from the AMP connector.
1 3.4
TROUBLESHOOTING
When malfunctioning is suspected , the first step in
troubleshooting is to examine the circuit breaker and its
power system for abnormal conditions such as:
a) Breaker tri p ping in proper response to overcurrents
or incipient ground faults.
b) B reaker remaining in a tri p-free state due to me-
chanical mai ntenance along its trip shaft.
c) Inadvertent shunt tri p activations.
WARNING: Do not ad just the programmer unit set
knobs while the breaker is carrying current.
Once it has been establ ished that th
can be o pened and closed normally from the test position ,
attention can be d irected to the trip device proper. Test­
ing is performed by either of two methods:
1 . Conduct high-current, single-phase tests on the
breaker using a high current-low voltage test set.
NOTE: For these single phase tests, special connec­
tions must be employed for RMS-9 breakers equipped
with Ground Fault.
programmer circuit will generate an unwanted "ground
fault" output signal which will trip the breaker. This
can be nullified either by
a) Using the Ground Fault Defeat Cable as shown in
Fig. 93. This special test cable energizes the pro­
grammer circuit in a self-cancelling, series-parallel
connection so that its output is always zero.
74
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Epic M icroVersaTrip ® Device (Cont . )
e circuit breaker
Any single-phase input to the
2 . Test the components of the R MS-9 system using
portable Test Set Type. The applicable test procedures
are detailed in i nstruction Book G E K-97367.
The time-current characteristics for the R MS-9 & Epic
M icroVersaTrip® Device are g iven i n curves G ES-6229
and G ES-6228.
1 04 -
FIG. TEST SET, CAT. NO. TVRMS
1 3.4.1
RESISTANCE VALUES
For use in troubleshooting the R MS-9 current sensors,
the resistance of the fixed windings is g iven in Table 1 5 .
1 5 - FIXED SENSOR
TABLE
RESISTANCE VALUES
Ampere
Rating
1 50
400
800
1 600
2000
The coil resistance of the R MS-9
device is approximately 7 ohms.
Resistance in Ohms
Between Terminals
1 0- 1 2
27-32
58-68
1 29-1 5 1
207-243
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Epic MicroVersaTrip ®