UPS Failure – Common Causes

UPS failure most common causes are:

Power Outage lasted LONGER than the battery autonomy of the UPS,
hence the UPS died as it had run out of battery stored power
The UPS has never been serviced or only randomly serviced.
NO maintenance contract in place – Been living on hope not serviced.
UPS Placed in correctly into bypass and fuses have been blown
The UPS is overloaded. When the GRID power failed the amount of
power required was MORE then the UPS could provide, so the UPS
went into internal bypass. As there was NO GRID power the UPS died.
Old batteries had not been replaced when the power outage occurred
so the UPS had no stored power to rely on- The UPS died
immediately that it switched to the batteries for power
UPS has frequency issues-
These occur when the UPS is grossly under loaded. For example a
100kVA UPS has only a 10kVA load.
UPS battery charger has failed and has not been re-charging the
batteries- No one noticed.
AC capacitors have failed –AC capacitors require replacement
regularly. Refer to manufacturers specifications. Every 5 -7 years as a
rule of thumb
DC capacitors have failed –DC capacitors require replacement
regularly. Refer to manufacturers specifications. Every 5 -7 years as a
rule of thumb
IGBT’s failed. Electrical components fail over years of use. Without
regular replacement they will fail
The UPS is old ; beyond it’s sell by date. Electrical components fail
over years of use. Without regular replacement they will fail
Dust built up inside the UPS has causing components to overheat and
fail
Fans have failed and caused the UPS to shut down
Water damage – Internal components have shorted out
NO air conditioning and the UPS has overheated and shut down
UPS has the load all on a single phase leaving the other two phases
without load. Over time this causes internal issues within the UPS
Rectifier failure or rectifier fuses have blown
Inverter failure or inverter fuses have blown