ADC HMS-318 Power and Frame Ground Procedure, Input Power Terminal Block TB1 Alarms Procedure

December 20, 2004 Chapter 2: Installation

Power and Frame Ground Procedure

IMPORTANT To avoid voltage differences from building up between the shelf ground (GND) bus and the

!ground pins of the management terminal that connects to the RS-232 ports, connect the shelf ground pins and the terminal ground bus to the TB1 FGND (frame ground) pin.

Step Action

1Use locally approved practices to connect #12 AWG (minimum) power wiring from -48Vdc Office Battery to -48VA and -48VB terminals on TB1-1 and TB1-2 (see <Cross-Ref>Figure 2).

2Connect #12 AWG (minimum) power wiring from the Battery Returns to BAT RTN terminals on TB1-3 and TB1-4 (see <Cross-Ref>Figure 2).

Note: Slots 1 through 11 on the HMS-318 List 3 shelf are powered by the -48VA bus. Slots 12 through 22 are powered by the -48VB bus.

In the HMU/HLU configuration, the HMU-319 is diode-OR’ed to both power busses to guard against power failure in the event that one power supply is lost. This feature requires the two ground (GND) terminals to be connected on the HMU card.

1 2 3 4 5

3/16-1261R1

-48VA -48VB

FUSE FUSE

15A MAX 15A MAX

TB1

BAT RTN

FGND

Figure 2-2. Input Power Terminal Block (TB1)

Alarms Procedure

Note: As described in “Power and Alarm Connections” on page 7, the HMS-318 List 3 shelf provides alarm outputs in the form of an Alarms wire-wrap field. This field consists of a three-pin wire-wrap header for alarm management. Before connecting the alarm inputs, you must first determine whether the external alarm equipment requires either an NO or an NC circuit to pass an alarm.

Step Action

1Use locally approved practices to connect the alarm inputs to the Alarms wire-wrap field (see Figure 2-3 on page 2-12).

Note: The HMU-319 is required for NO and NC alarm operation.

LTPH-UM-1261-01 2-11