American Power Conversion MX28B4800, MX28B2400 Telecom Fuse Installation, GMT Fuse Installation

Telecom Fuse Installation

1)Remove the fuse(s) from the desired location(s) by pulling the fuse holder straight out of the fuse holder base.

2)Install the fuse(s) by bolting the fuses(s) into the fuse holder.

3)Re-install the fuse holder by pushing the holder straight in.

4)Connect the alarm wiring to the alarm terminal at the output of the fuse holder base.

5)Connect the alarm wiring to the Fuse alarm Wago breakout board.

NOTE: Fuse alarm contacts sense the voltage on the output of the fuse. When the fuse is blown the output voltage is zero. Only connect one fuse to each Wago connector in any bay.

GMT Fuse Installation

Fuse holders that accommodate GMT fuses are located on the interface card mounted in the top left side of the unit. Insert the fuse in the holder; observing the tripped indicator is correctly oriented. These fuse holders are only connected to -48VDC if the system has been purchased with the GMT fuse option. This option supplies -48VDC to lugs on the interface card through a 50 Amp circuit breaker located in circuit breaker Position 1. The interface card provides fuse holders for eight fuses, labeled “F1” through “F8”, which can be used for small -48V DC loads. Use the chart shown in Figure 3.7-3 to help determine what size fuses will carry the desired current. Refer to Figure 3.9-1 for Interface board GMT fuse locations.

NOTE: The controller will not report GMT Fuse failures in the MX28B1200 system. Only telecom style fuses can be monitored. Use GMT fuses only in non-essential applications.

		AMBIENT TEMPERATURE
		20° C	50° C	60° C
	10 Amp	7 Amp	6 Amp	5 Amp
FUSE SIZE
	12 Amp	8 Amp	7 Amp	6 Amp
	15 Amp	10 Amp	9 Amp	8 Amp
	Figure 3.7-3 GMT Fuse Temperature De-rating Chart

MX28B1200/2400 MX28B1200/4800 –48 VDC User’s Manual Page 21