Single phase uninterruptible power supplies (UPSs) are installed between an alternating current (AC) outlet (i.e., a wall outlet or power strip) and an electronic device (such as a computer, server, or phone equipment) to provide power conditioning, redundancy, and distribution for electronic equipment loads. Additionally, single phase UPSs protect electronic devices and essential data from power disturbances (outages, sags, surges, spikes, noise, etc.).
Volt-amp rating, wattage rating, and input voltage range are all specifications for single phase UPSs.
The volt-amp (VA) rating of a unit is equal to the maximum number of volts multiplied by the maximum number of amperes (amps). Take note that the VA rating does not correspond to the equipment's power consumption, which is expressed in watts (W).
Only when the number of volt-amps is uncertain, a watt rating less than or equal to the VA rating is stated.
The input voltage range, or the precise identification of the electrical system, is crucial for selecting single phase UPSs correctly.
With an online UPS, the load is supplied by a continuous-operation power converter that receives its input from a DC power supply. This direct current supply is comprised of a battery and a huge battery charger connected in parallel. The inverter operates in parallel with the load to supply AC power and is only capable of handling full load power if the AC input fails. A hybrid UPS regulates electricity by the use of a ferroresonant transformer. This transformer maintains a consistent output voltage regardless of the input voltage variation and offers excellent protection against line noise. UPSs that operate in the off-line or standby mode are also available.