GE AKR-30 Series Maintenance Manual page 242

SECTION 1 2- MicroVersaTrip™ Trip Device (Cont.}
1 2.3
FLUX S H I FTER TRIP DEVICE
The only d ifference between the MicroVersaTrip and
SST flux shifter trip devices is the solenoid winding. Refer
to Section 1 0.3 for details.
When replacing a M icroVersaTrip flux shifter, AM P ex­
traction tool Cat. No. 455822-2 is req uired to remove the
socket leads from the AM P connector.
1 2.4 TROUBLESHOOTING
When malfunctionion is suspected, the first step in
troubleshooting is to examine the circuit breaker and its
power system for abnormal conditions such as:
a) Breaker tripping in proper response to overcurrents or
inci pient ground faults.
b) Breaker remai ning in a trip-free state due to
mechanical maintenance along its trip s h aft.
c) Inadvertent shunt trip activations.
WARNING:
DO NOT CHA NGE TA PS ON THE CUR­
REN T SENSORS OR A DJUST THE PROGRAMMER
UNIT SET KNOBS WHILE THE BREAKER IS CAR­
RYING CURRENT.
FIG. 87A - MICROVERSATRIP®
COMPONENT WITH TAPPED SENSORS
64
Once it has been establ ished that the circuit breaker
can be opened and closed normally from the test position,
attention can be di rected to the tri p device proper. Testing
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 Micro Versa Trip breakers
equipped with Ground Fault. Any single-phase input
to the programmer circuit will genera te an unwanted
"ground fault" output signal which will trip the
breaker. This can be nullified either
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.
2. Test the components of the MicroVersaTrip system
using portable Test Set Type TVTS1 (Fig.
pl icable test proced ures are detailed in instruction Book
G EK-64464.
The time-current characteristics for the M icroVersaTri p
Trip Device are given in curves G ES-6 1 95 and G ES-6199.
FIG. 878 - RMS-9, EPIC MICROVERSATRIP®
AND MVT -PLUS O R MVT -PM COMPONENTS
WITH FIXED SENSORS
by
88).
The ap­