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3.
Set the ground fault mode switch.
On trip units with ground fault protection, the ground fault
selection switch on the side of the trip unit must be set to the
appropriate sensing scheme—Residual or Ground Return—
prior to installing the trip unit. The ground fault sensing
schemes are discussed in Section 5.7, Ground Fault Sens-
ing Scheme.
Residual is the factory pre-setting and is the setting most com-
monly used.
4.
Check the label on the side of the trip unit.
Trip Device
Cat. No:
For use with Types SB Circuit Breakers Frame Rating
Listed Circuit Breaker Trip Unit Issue No. G-1126
Siemens Energy & Automation, Inc. Bellefountaine, OH 43311
Before attempting to install the trip unit, check the label on the
side of the device to make sure that it is the proper device for
the SB circuit breaker.
Ground Fault Mode Switch
Ground
Residual
Return
5.
Check alignment of pins and holes.
If there is any doubt about a trip unit being the proper device
for an SB circuit breaker, check the alignment of the pins and
holes. A built-in rejection scheme will prevent the installation of
a trip unit into a breaker for which it is not intended.
This scheme consists of two pins on the support plate on which
the trip unit will set into two matching holes in the bottom of the
trip unit. If the holes in the bottom of the trip unit cannot be
aligned with the pins, the trip unit cannot be installed in the SB
circuit breaker.
6.
Mate the pin connectors.
Mate the connector half on the back of the trip unit with its cor-
responding connector half in the circuit breaker.
Installation
11
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