NoWire - Your value added partner in the ICT sector

Product Overview :

a) Why should you use an UPS?

An UPS not only provides you with power for your electronic equipment while the Eskom power is down it also protects you against surges when the Eskom grid is switched off and when the Eskom grid is switched back on. These surges can and very often results in permanent damage or corruption of data files. The level of protection provided and the time for which the UPS can provide you with power depends on the UPS you choose. If you only need time to close down the computer a smaller unit can be used.

b) VA Rating

The VA Rating you require will depend on the load of the equipment you want to connect to the UPS.
The VA Rating required is the current required by the equipment or PC use from mains power (230V AC) divided by the Power Factor (PF) of the equipment.

Example:

A basic computer requires about 1.5 to 2 Amps (current)
Mains voltage used : 230VAC (AC voltage)
Power factor of PC: 0.6 -0.7 (typical for computer equipment)
2A x 230V = 460W / 0.65 PF = 708 VA

c) Backup Time

The backup time is proportional to the load that is connected to the UPS. The higher he load the less the backup time.

d) UPS Topologies & Protection Offered:

Off-Line

The UPS provides the mains via a small limited Filter under normal circumstances. When the mains power fails the UPS switches, via a relay, over to inverter of the UPS to provide power for long enough to save open files and shutdown your computer.

Line Interactive

Your computer is running at standard mains via a small AC Filter under normal circumstances. After a power failure this type of UPS system switches, via a small relay, over to a simple inverter to provide power to allow you to save your open files and shutdown your computer. The system also normally includes a limited AVR (Automatic voltage regulator) which limits incoming mains fluctuations.

The backup time is normally short and will depend on the VA rating of the UPS and the amount of power your equipment draws from it. This type of UPS will give you limited protection against power surges, spikes and sags.

Single Conversion

This type of UPS system will provide protection and backup on power failure for some applications. Your computer system is always running via a constant voltage transformer which basically regulates the output voltage and also filters, to a large degree, spikes, sags, etc.

The single conversion provides a adequate protection for computers and any some other load. It is often less efficient but provides better protection then the older technology.

Double Conversion

This type of UPS system will provide total protection and backup on power failure for critical applications. Your computer system is always running on electronically produced power and it is not directly connected to the utility supply. The double conversion, double isolation and to ensure the cleanest, most compatible AC output for computers and any other critical load. Although this unit is the more expensive it provides by far the best protection for critical devices. This type of UPS is recommended for all critical applications like servers etc.