18 MX28B
NOTE: Circuit breaker alarm contacts close when the circuit breaker is trippedbut not when it is turned OFF.***** CAUTION *****
During circuit breaker installation, carefully align the breaker alarm terminals with the alarm
terminal board to avoid breaker terminal damage.
3) Reattach the circuit breaker cover panel.
Figure 5.7-1. Installation of Circuit Breakers
5.7.2.2 GMT Fuses
Fuseholders that accommodate GMT fuses are located on the interface card mounted in the
top left side of the unit. These fuseholders are only connected to -48V dc if the system has
been purchased with the GMT fuse option. This option supplies -48V dc to the fuseholders
through a 50 A. circuit breaker located in circuit breaker Position 1. The interface card
provides fuseholders for eight fuses, labeled “F1” through “F8”, which can be used for small
-48V dc loads. The maximum fuse size that should be used is 10A.
5.7.3 Load Connections
5.7.3.1 Circuit Breakers
Connections for -48V dc loads require standard two-hole lugs for #10 screws on 5/8”
centers and are located directly above the corresponding circuit breaker. The load returns
connect to the return bus located just above and rearward of the breaker connection points