GE Industrial Solutions ProTrip Conversion Kits AK-1-15 and AK-1-25 User Manual

Page 14

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 18.

4. On ground fault breakers serving four-wire loads,

check that the neutral sensor is properly con-

nected, as indicated in Figure 18. 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 disconnect

block through to the trip unit wiring harness

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 Resistance, ohms

AK-1-15

150

225

9–12

14–18

AK-1-25

225

600

14–18

40–50

Table 1. CT resistance values.