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Why might the Overload LED be lit on my APC Back-UPS?


Why might the Overload LED be lit on my APC Back-UPS?

This indicator is lit whenever equipment connected to the battery back-up outlets is drawing more power than the UPS can provide. This symptom is also
accompanied by a shrill constant tone. If the overload is strong enough, the UPS may shut down turning off its output in order to protect its circuitry from damage.

Product Line:

All APC Back-UPS Product Families.


All APC Back-UPS Product Families.


Each model of Back-UPS is capable of handling up to a certain amount of equipment. For example, the BP350U is rated for 350 Volt Amps (or 220 Watts) and the BP500U
is rated for 500 Volt Amps (or 315 Watts). Verify that your equipment plugged into the Battery Backup outlets does not exceed the VA rating (denoted by the number in the
model number of your UPS) by using APC's UPS Sizing Tool at


Try moving one or more pieces of equipment to the Surge Protection outlets. If the Overload Led remains lit at this point, try turning the unit off and
back on again. If you have verified that your connected equipment does not exceed the ratings of the unit, please contact APC's Technical Support.
Please be near the unit to further troubleshoot the problem over the phone.

Note: It is normal for the Overload Led to briefly illuminate when turning the UPS on with the equipment connected. When using the UPS as a ""master on/off""
switch, the Overload Led will illuminate briefly when the connected equipment powers up at the same time that the UPS does.

If the Overload Led is flashing CONTINUOUSLY, this may indicate an internal fault with the UPS. If this is the case, please contact APC's Technical Support.

APC Technical Support can be reached in the United States and Canda at 800-800-4272. For support outside of North America please refer to APC's

worldwide contact page at: to find the nearest APC location.
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