GE MicroVersaTrip Plus Installation Instructions Manual page 18

from all power sources, perform the following
procedure:
1. Check that all phase sensors are the same type
(current range).
2. Verify that the tap settings on all three phase sen-
sors are identical.
3. Verify that the wiring harness connections to the
sensors have the proper polarity (white lead to
common, black lead to tap), as shown in the
cabling diagram in Figure 22.
4. On ground fault breakers serving four-wire loads,
check that the neutral sensor is properly con-
nected, as indicated in Figure 22. In particular,
check the following:
a. Verify that the neutral sensor has the same rat-
ing and tap setting as the phase sensors.
b. Verify continuity between the neutral sensor
and its equipment-mounted secondary discon-
nect block. Also check for continuity from the
breaker-mounted neutral secondary discon-
nect block through to the trip unit wiring har-
ness connector.
c. If the breaker's lower studs connect to the
power source, then the neutral sensor must
have its load end connected to the source.
d. Verify that the neutral conductor is carrying
only the neutral current associated with the
breaker's load current (the neutral is not
shared with other loads).
5. If the preceding steps fail to identify the problem,
then measure the sensor resistances. The appro-
priate values are listed in Table 1. Since the
phase and neutral sensors are electrically
identical, their resistances should agree closely.
Breaker CT Rating, A
LA-600
LA-800
LA-1600
Table 1. CT resistance values.
18
Resistance, ohms
150 10.1–15.2
225 14.5–22
600 4–58
150 10.1–15.2
400 27–41
800 51–77
800 54–81
1600 110–166