11
Alarm Contact Closures
The DC-UPS Alarm Contact Closures provide relay contacts to remotely monitor the status
of the unit. The AC Fail relay indicates whether the unit is operating on AC power or on
battery power. The function of the Battery Test Fail relay changes based on the status of the
AC Fail relay. If the DC-UPS is operating on AC power, The Battery Test Fail Relay
indicates the status of the last battery test. If the DC-UPS is operating on Battery power, the
Battery Test Fail Relay indicates whether the battery voltage is greater than or less than
44Vdc.
AC Fail
Relay State
Battery Test
Fail Relay
State
DC-UPS Operating Status
NO
NC
On AC Power, Battery Test Pass
NO
NO
On AC Power, Battery Test Fail
NC
NC
On Battery Power, Battery Voltage > 44.0Vdc
Or
DC-UPS shutdown
NC
NO
On Battery Power, Battery Voltage < 44.0Vdc
The alarm contacts are accessible via an RJ45 connector on the rear panel of the DC-UPS.
The Alarm Contact connector pinouts are shown below.
Both normally open and normally closed contacts are provided to suite the user’s external
monitoring circuitry. The alarm contacts have a 2 Amp rating. The NO and NC contacts will
change state when an alarm condition occurs.
Pin #
Function
Comment
1
Battery Test Fail NC
Battery OK/Battery Voltage > 44 Vdc
2
Battery Test Fail Common
3
Battery Test NO
Battery Test failed /Battery Voltage < 44 Vdc
4
No connection
5
No connection
6
AC Fail NC
AC Failure has occurred
7
AC Fail Common
8
AC FAIL NO
Operating Normally
Alarm Contact pinouts