76
External Accessories
Neutral Sensing Transformer
Important
The SB series of electronic trip circuit breakers equipped with
ground fault protection may be used in the Residual or Ground
Return modes. When used in the Residual mode the orienta-
tion of the neutral sensing transformer is important for proper
operation. See illustrations below for proper orientation of the
neutral sensor for Residual mode Ground Fault. Orientation of
the neutral sensor is not required when used in the Ground
Return mode of Ground Fault.
Standard Connection
Reverse Connection
Installation of neutral transformer
Terminal Connections
After properly orienting and mounting the neutral sensing
transformer, maintain the correct polarity by connecting ter-
minal LT1 1 on the circuit breaker to terminal X1 on the neutral
sensor, and terminal LT12 on circuit breaker to terminal X2 on
the neutral sensor.
Trip Unit Connections
Check to see if there are wires routed from terminal block
positions LT1 1 and LT12 to the inside of circuit breaker. If
there are, discard the 2 connection wires supplied with the
transformer. If not, these wires will need to be installed.
Remove breaker front cover and trip unit (see pages 36-37 of
guide). Follow steps 2 and 3 on page 54. With a small
screwdriver, press in tab on right side of 36 pin trip unit
connector and release it from mounting bracket. Connect the
wire marked LT11 from trip unit connector position #8 to
terminal block position LT11. Connect wire marked LT12 from
connector position #15 to terminal block position LT12. Make
sure these connectors are fully seated and locked into con-
nector. Route wires as shown below. Use number 1 8-gauge
copper wire (to be supplied by customer) for lead wires .
Replace trip unit and front cover taking care not to pinch any
wires.
Summary of Contents for SBA 1200
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