Transfer Time

Transfer Time

The amount of time it takes a stand-by or off-line type UPS to sense a power interruption and switch from utility output to inverter output. Normally expressed in millisecond.

Cold start function

Cold start function

The UPS can be started from battery directly without AC utility. Some people also name it as DC start.

Backup Time/Runtime

Backup Time/Runtime

The duration that UPS supplies backup power to the electrical appliances while power failure. The unit of backup time is minute and calculates backup time from black out happening to battery used up.

Crest factor

Crest factor

The ratio between the crest (peak or maximum) value and the root-mean-square (RMS) value of an alternating current. Some computer power supplies draw current with a crest factor of between two and three.

Radio Frequency Interference (RFI)

Radio Frequency Interference (RFI)

It is undesirable noise produced by a power supply or other electrical or electronic device during its operation. In power supply technology, RFI is usually taken to mean the same thing as EMI.