Alpha Technologies
71
5
Maintenance
5.1
Measuring the Battery Backup Time
This test measures how long the batteries can provide backup battery power. Because it is load
dependant, the time needed to carry it out varies. Refer to Figure 3.10.1, “Battery Discharge
States” to see the various states the unit and the batteries go through as the battery discharges.
This test should be done once a year when the batteries are new. When the
batteries are 3 years or older, do it once every 3 months.
The unit should have been in line mode for at least 24 hours before doing this
test so that the batteries are fully charged.
Procedure
1
Turn off the upstream circuit breaker.
The UPS goes into Battery mode (the
output LED is flashing and the LCD dis-
plays “BATT”. Record this start time
2
Record when the low battery warning (the
output and alarm LEDs are flashing and
the LCD displays “INVOFF”) appears.
This is the battery reserve time. Add 10%
to the reserve time. This is the total battery
run time
3
Turn on the upstream circuit breaker to
provide line power to the unit. The unit
returns to line mode and starts charging
the batteries.
Backup Time Test Finished
Example
1) Start time is 1pm. The low battery warning appears at 2pm.
2) The battery reserve time is 1 hour. 10% of 1 hour is 6 minutes.
3) The total battery run time is
1 hour and 6 minutes
.
Alpha
5M 120/60N
Novus 1800
BATT
Alpha
5M 120/60N
Novus 1800
LINE
Alpha
5M 120/60N
Novus 1800
INVOFF