3.6. DC Power Output Over-Current Protection

DC Circuit Breakers

A standard 24-position plug-in circuit breaker tier provides -48V distribution. Various circuit breaker sizes from 1 to 100 amps are available, with 60-100 amp breakers requiring two positions and a circuit breaker adapter kit. The breaker tier is connected at its center to the -48V DC bus, and each side has an ampacity of 300A. It is therefore necessary to balance the load on the MX28B-400 plant to avoid overloading the output bus. Also when planning the output installation, take into consideration the configuration of the plant and the number of rectifiers installed.

Any combination of up to 24 single (1-50 Amp) or up to 12 double (60-100 Amp) breakers may be installed. Figure 3.6-1shows the power plant’s DC distribution section with the front cover removed.

Figure 3.6-1 DC Distribution (Front Cover Removed)

Available plug-in circuit breakers are shown below. These are only breakers and do not include any hardware.

MX28B200/400 –48 VDC User’s Manual (990-9133)

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American Power Conversion MX28B200 user manual DC Power Output Over-Current Protection, DC Circuit Breakers