Instruction manual

ATLAS 800 Series System Manual ATLAS 890 Rear Panel

Engineering Guidelines

Alarm Relay Connection

This connection alerts the user when a pre-selected alarm condition exists. The four-pin, removable

terminal block connects with external wiring (see Pinout 9). Refer to DLP-12, Connecting to the

ATLAS 890 External Input, for detailed instructions. Clear the alarm condition by pressing the ACO switch

located on the front panel of the ATLAS 890.

External Input Connection

This connection alerts the user when a pre-selected external alarm condition exists and could be used, for

example, to monitor a UPS with dry contacts or another ATLAS 890. The three-pin, removable terminal

block connects with external wiring (see Pinout 10). Refer to DLP-12, Connecting to the ATLAS 890

External Input, for detailed instructions. Clear the alarm condition by pressing the ACO switch located on

the ATLAS 890 front panel.

Pinout 9. ATLAS 890 Alarm Relay Connector

Pin Name Description

1 NC Normally closed, but opens when a preselected alarm condition is present.

2 NO Normally open, but closes when a preselected alarm condition is present.

3 COM Common connection between external circuitry and NC or NO terminal.

4 GND Chassis Ground

Pinout 10. ATLAS 890 External Relay Monitor Connector

Pin Name Description

1 Input Monitors for the presence or absence of -48 VDC

2 Vout -48 VDC @ 1 mA

3 GND Chassis Ground