APC MX28B-2400, MX28B-1200 manual AC Input Power, Battery connections, DC Distribution

MX28B-1200 PRODUCT MANUAL

4.5AC Input Power

Each rectifier requires 208/220/240V ac, single- phase, 50/60 Hz, supplied through an external 20- amp two-pole breaker. A vertical wire channel at the rear of the box frame provides terminal strips for ac input power connection of each shelf. Separate “Earth Ground” terminal bars are provided for the connection of the safety ground wires. A power entry box is provided at the top and rear of the box frame where AC wiring conduit can be attached. Refer to Figure 4-3.

4.6Battery connections

Battery connections are made at the top rear of the unit. The -48V and Battery Return buses each provide four sets of threaded 3/8”-16 holes on 1 inch or 1 ¾ inch centers for connecting two-hole battery cable lugs. Refer to Figure 4-3.

A battery disconnect breaker is required external to this equipment. The power plant can monitor auxiliary contacts from this breaker. Battery temperature compensation is available. APC’s master control unit, in conjunction with the optional temperature monitor sensor cable, is used to implement this function.

Revision B

+

-

Battery

Connections

AC entry and vertical wiring channel

4.7DC Distribution

A standard power distribution module within the power box frame contains two 24-position plug-in circuit breaker columns, providing -48V power for customer loads. Each breaker column is connected at its center to the -48V dc bus, with each side having an ampacity of 300A. Connections for the -48V dc loads are located directly to the side of 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 a return bus directly opposite the circuit breakers. These return buses contain patterns for 28 two-hole #10-32 lugs on 5/8-inch centers, and 14 two- hole ¼”-20 lugs on a double-pattern of either 5/8-inch or 1-inch centers. Figure 4-4 shows the power plant’s dc

Figure 4-3 Power Entry Box and Battery

Connections

Circuit Breaker Positions (-)

Load Returns (+) and

Facility Main Ground Bus

Figure 4-4 DC Distribution

10 MX28B-1200/2400