What is a UPS?
UPS stands for Uninterruptible Power Supply. It is a device that sits between an A/C socket or main AC supply panel and any electrical load (such as a computer, server, phone equipment, audio-, TV, lighting, air-conditioner and etc.) to prevent power problems (outages, sags, surges, spikes, noise, etc.) from affecting
- the performance
- life of the electronic device
- vital data
These units contain batteries which generate DC voltage converter by UPS to AC voltage to supply power to the connected load during a power failure or extreme fluctuations of voltage/frequency of incoming power.
Which UPS types available?
Standby (Off-line, Passive Stand-By) UPSs
Allow IT equipment to run off utility power until the UPS detects a problem, at which point it switches to battery power. Some standby UPS designs incorporate transformers or other devices to provide limited power conditioning as well.
Line-interactive UPSs regulate input utility voltage up or down as necessary before allowing it to pass through to protected equipment. However, like standby UPSs, they use their battery to guard against frequency abnormalities.
Double-conversion (Online) UPS
As the name suggests, these devices convert power twice. First, an input rectifier converts AC power into DC and feeds it to an output inverter. The output inverter then processes the power back to AC before sending it on to IT equipment. This double-conversion process isolates critical loads from raw utility power completely, ensuring that IT equipment receives only clean, reliable electricity.
In normal operation, a double-conversion UPS continually processes power twice. If the AC input supply falls out of predefined limits, however, the input rectifier shuts off and the output inverter begins drawing power from the battery instead. The UPS continues to utilize battery power until the AC input returns to normal tolerances or the battery runs out of power, whichever occurs sooner. In case of a severe overload of the inverter, or a failure of the rectifier or inverter, the static switch bypass path is turned on quickly, to support the output loads.
What is a Generator?
A generator is a device that converts motive power (mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines and even hand cranks.
Generators have engine, which is motioned by fuel (diesel, petrol and etc), i.e. generators use different types of fuel to operate and generate electricity.
What is an Inverter?
A power inverter, or inverter, is an electronic device or circuitry that converts direct current (DC) to alternating current (AC). The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. Generally small inverters are 12V to 48VDC input, bigger industrial inverters can convert from up to 960VDC and higher.
The inverter does not produce any power; the power is provided by the DC source – usually batteries.
Some inverters have also a charger, which charges connected batteries.
What is a Voltage Regulator?
A voltage regulator (or voltage satbiliser) is an electronic circuit that provides a stable DC voltage independent of the load current, temperature and AC line voltage variations. A voltage regulator may use a simple feed-forward design or may include negative feedback. It may use an electromechanical mechanism, or electronic components
Power Conditioner (or Line Conditioner) is a device intended to improve the quality of the power that is delivered to electrical load equipment. Besides of Voltage Regulation commonly provides surge protection as well as noise filtering. Power Conditioners usually are used for home or office applications and has up to 10 or more receptacles or outlets.
What is a Surge Suppressor (Surge Protector)?
A surge suppressor (or surge protector or surge diverter) is an appliance or device designed to protect electrical devices from voltage spikes and surges. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or shorting to ground any unwanted voltages above a safe threshold.
Generally it also has built-in noise filter, which blocks unwanted noise, RFI and EMI fluctuations from getting to a connected load. Please note that Surge Suppressors do not regulate or stabilize voltage!
What is a PDU?
A power distribution unit (PDU) is a type of electrical component that distributes and manages electricity supply to computers, servers and networking devices within a data center environment. It provides a central unit to control and distribute electricity across the data center components.
Power distribution units are also known as main distribution units (MDU).
What is the difference between W and VA (or kW and kVA)?
The primary difference between W (watt) and VA (volt-ampere) is the power factor (PF). W is the unit of real power and VA is a unit of apparent power (or real power plus re-active power). The power factor, unless it is defined and known, is therefore an approximate value (typically 0.8), and the VA value will always be higher than the value for W.
For example in 1000VA device (UPS, inverter or voltage regulator) and Power Factor 0.8, W value will be 1000VA x 0.8 = 800W. However on low-end UPSs PF can be as low as 0.5, so you have to read UPS specifications carefully.
Same applied to kVA and kW relation, as “k” stands for “kilo”, which means 1000 times bigger value. i.e. 1kVA = 1000VA, and 1kW = 1000W
How do define power capacity of your equipment?
You will need to find out the power requirement of the equipment to be supplied by the UPS/inverter/Voltage Regulator.
The power requirements could be listed on your equipment in Volt-Amps (VA), Watts (W) or Amps (A). If it listed in Ampers (A) you will need to multiply Amper value by 220 (AC voltage). For example, When you have these, you can call us on 012 409 3313, and we can help you decide which size and what type device you need.
How to define required back-up time (when choose UPS, inverter, generator)?
Back-up time is a time which UPS can provide output power to connected load after main electricity supply goes off. You have to define how much time you need your equipment to run during blackout. Depending on back-up time required batteries capacity and quantity will be chosen.
Please note that back-up time DOES NOT DEPEND on UPS or inverter/generator POWER RATING, it depends ON NUMBER AND CAPACITY OF BATTERIES which this UPS uses.
However, it is obvious that higher power VA UPS devices uses more and stronger batteries.
In case of generator back-up time will depend on generator fuel tank capacity, as it will produce electricity as long as there’s a fuel available.