American Power Conversion MX28B1200, MX28B2400+27V manual Installation of Circuit Breakers

Rev 1 MX28B-1200+27V PRODUCT MANUAL

5.8.2Installation of Circuit Breakers

1)Remove the metal circuit breaker cover panels.

2)Use diagonal cutters to cut the metal web of the breaker panel “knock-outs” at the desired breaker locations.

3)Install the circuit breaker(s) by snapping the top terminal onto the upper bus bar and rotating the unit down until the second terminal snaps onto the breaker termination post as shown in Figure 5-8. The breaker alarm terminals are designed to make contact with the alarm terminal board as the breaker is snapped into place.

NOTE: Circuit breaker alarm contacts close when the circuit breaker is tripped but 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.

4) Reattach the circuit breaker cover panels.

Figure 5-8 Plug-in Circuit Breaker Insertion

5.8.2.124V Circuit Breaker Load Connections

Connections for the +24V DC loads are located directly above the corresponding breaker. A typical load connection would utilize a #6 AWG wire with a two-hole lug on 5/8-inch centers, attached with standard #10-32 mounting screws.

The load return cables for each circuit breaker section connect to the return bus directly above the top row of circuit breakers. These return buses contain patterns for 40 two-hole #10-32 lugs on 5/8-inch centers.

5.8.2.2–48V Circuit Breaker Load Connections

Connections for the –48V DC loads are made directly above the corresponding breaker. A typical load connection would utilize a #6 AWG wire with a two-hole lug on 5/8-inch centers, attached with standard #10-32 mounting screws.

The load return cables for each circuit breaker section connect to the return bus located above the upper circuit breakers.

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