MX28B 19
as seen in Figure 5.7-1. The return bus provides 24 sets of threaded #10-32 holes on 5/8”
centers and four sets of threaded ¼”-20 holes on ¾” centers for connection of two-hole lugs
on load return wires.
5.7.3.2 GMT Fuses
Connections to the GMT fuses are made at terminal block connectors labeled “F1” through
“F8” that are located on the interface card mounted in the top left side of the unit. Each
connector has two positions, labeled “-48V” and “RTN”, for connection of the -48V dc load
and load return wires.
5.8 Battery Temperature Probe Installation
The optional temperature probe is used to monitor the battery string temperature. To get
the most representative temperature measurement, the probe should be placed in contact
with a battery cell that is centrally located. The probe should be placed directly in contact
with the cell (not the frame surrounding the cell). Generally, the cell cover can be used; be
careful not to allow the probe body to touch the terminals.
1) Plug the connector end of the temperature probe into J5 the control unit backplane
card.
2) Route the cable as required to position the probe on the selected battery cell
3) Remove the adhesive protection strip from the probe body and press the adhesive
side of the probe on the battery cell cover.
5.9 Power-Up and Checkout
Before initiating power-up and checkout, ensure that the following conditions exist:
1) Make sure that the external circuit breaker protecting the cables from the battery to
the power plant is turned OFF (the battery cables should be connected to the
power plant, but the battery should not be connected).
2) Make sure that all load circuit breakers are turned OFF (including the one feeding
the GMT fuses if the unit has the GMT fuse option).
3) Verify that all rectifiers have been installed.
5.9.1 Apply AC Power
Turn on the circuit breakers that supply ac power to the rectifiers in the MX28B dc power
plant. The main screen should appear on the control unit display (see Figure 5.9-1). The
display on the control unit is a 2-lines by 16-characters display. The cursor cycles below
the characters of the active selection on the display. Information shown in the second line
of Figure 5.9-1 that extends beyond 16 characters (to the right of the “S” in “ALARMS”) can
viewed on the control unit display by using the scrolling controls (refer to Section 6 for
operation of the control unit).
NOTE: When ac power is initially applied, there is a 60-second period during which no
alarms are reported.