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This is the time that the battery must support the load and is also often called back-up or discharge time

A total loss of electrical power.

A low voltage condition over an extended period of time.

An ac power path around a UPS.

An automatic bypass is controlled by a UPS and operated under fault or overload conditions to maintain power to the protected load.

A manual bypass is a user switch on a UPS allowing a complete electrical bypass of the unit, used when there is a total UPS failure or when carrying out maintenance or repair without shutting down the load. Some parts of the UPS – the input and output terminations for example – may remain live.

A service or maintenance bypass is a manual bypass allowing complete isolation, maintenance, or removal of the UPS without shutting down the load.

Common Mode Noise
Disturbances between the neutral and earth or grounding conductors. Noise may result from injection into the neutral or grounding wires, wiring faults, or overloaded power circuits.

Crest Factor
Expressed as the ratio between the crest (peak or maximum) value of a current to the root-mean-square (rms) value. A square wave of current has a crest factor of one. A sine wave has a crest factor of 1.414. Typical computer power supplies draw current with a crest factor of between two and three.

Current Limit
The function of a circuit or system that maintains a current within its prescribed limits. UPS systems have an electrical current limit that regulates the output current to a value within the UPS limits.

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