APC 990-1587 Power Supply User Manual


 
9
PROBLEM AND/OR POSSIBLE
C
AUSE
S
OLUTION
THE OVERLOAD LED IS ILLUMINATED AND THE UPS EMITS A SUSTAINED ALARM TONE
The UPS is overloaded. The
connected equipment is draw-
ing more VA than the UPS can
sustain.
The connected equipment exceeds the specified “maximum load.”
The alarm remains on until the overload is removed. Disconnect nonessen-
tial equipment from the UPS to eliminate the overload.
The UPS continues to supply power as long as it is online and the circuit
breaker does not trip; the UPS will not provide power from batteries in the
event of a utility voltage interruption.
If a continuous overload occurs while the UPS is on battery, the unit turns
off output in order to protect the UPS from possible damage.
THE REPLACE BATTERY/BATTERY DISCONNECTED LED IS ILLUMINATED
This LED flashes and a short
beep is emitted every two sec-
onds to indicate the battery is
disconnected.
Check that the battery connector on the rear panel is fully engaged.
Weak battery. Allow the battery to recharge for 24 hours. Then, perform a self-test. If the
problem persists after recharging, replace the battery.
Failure of a battery self-test. The UPS emits short beeps for one minute and the replace battery LED
illuminates. The UPS repeats the alarm every five hours. Perform the self-
test procedure after the battery has charged for 24 hours to confirm the
replace battery condition. The alarm stops and the LED clears if the battery
passes the self-test.
THE SITE WIRING FAULT LED ON THE REAR PANEL IS ILLUMINATED (120V MODEL ONLY)
The UPS is plugged into an
improperly wired utility power
outlet.
Wiring faults detected include missing ground, hot-neutral polarity reversal,
and overloaded neutral circuit.
Contact a qualified electrician to correct the building wiring.
THE INPUT CIRCUIT BREAKER HAS TRIPPED
The UPS is overloaded. The
plunger on the circuit breaker
has popped out.
Reduce the load on the UPS by unplugging equipment. Press in the plunger
on the circuit breaker.
THE AVR BOOST OR AVR TRIM LEDS ARE ILLUMINATED
The system is experiencing
excessive periods of low or
high voltage.
Seek qualified service personnel to check your facility for electrical prob-
lems. If the problem continues, contact the utility company for further as-
sistance.
UPS OPERATES ON BATTERY ALTHOUGH UTILITY VOLTAGE EXISTS
The UPS input circuit breaker
has tripped.
To reduce the load on the UPS, unplug equipment and press in the plunger
on the circuit breaker.
The line voltage is very high,
low or distorted.
Move the UPS to a different outlet on a different circuit, as inexpensive fuel
powered generators may distort the voltage. Test the input voltage with the
utility voltage display (see Operation). If acceptable to the connected
equipment, reduce the UPS sensitivity (see User Configurable Items).