This is the abbreviation for Uninterruptible Power Supply. This means that your power-supply will not be interrupted even if the source of power is cut. Your equipment will continue functioning without an interruption - as if nothing had occurred. The UPS consists of an Inverter, Transformer, Voltage regulator, Charger and Batteries. UPS’s are more robust and therefore used for heavier equipment and machinery, lasting for longer periods of power-cut time.
UPS sizes range from 500VA to 240 KVA. The battery size will depend on:
a) How much power is needed to operate the equipment effectively and
b) How much back up time is required for the equipment to continue operating.
To calculate See: Battery Calculator http://kbc.powerpixels.co.za/Battery-calculator.html
An inverter is the subassembly of a UPS that converts DC power to AC power. The inverter is the device that changes DC (12v, 24v or 32v etc.) from a battery to 220VAC. regulating the output constantly even while the battery is discharging - ensuring a stable 220VAC supply. Also smoothing out any small irregularities that may cause voltage fluctuations. When calculating the battery size for your requirements the inverter allowance is included in the calculation. These units draw very little power from the battery and are generally quite reliable if not overloaded.
The smaller type UPS’s are used for general office and home equipment do not need to convert large quantities of power for extended periods of time and therefore use a different technology in the design. These UPS units are designed to be more cost effective and exclude the use of a large expensive transformer to convert power. High frequency conversion and 'line interactive' technology is used. This type UPS, or power backup, is commonly referred to as an ‘Inverter’ (which includes the inverter, charging circuit and battery). Inverters are used in general office and household equipment that draw less current and need to stay running for a shorter period of time, reducing their costs. Running an Inverter UPS is a very cost effective means to standby power.
In our next article we will discuss Power Surges and your UPS.
ARTICLE SOURCE: http://www.articlesbase.com/technology-articles/how-to-choose-your-ups-or-inverter-for-standby-power-798698.html