Some things to consider are:
What is your UPS application? Many things can be plugged into UPS so they are protected from a range of power problems. One thing to be avoided is lazer printers. There are printers that exist that are compatible, but most home printers are not.
What level of protection does your ups offer?The level of protection is where the various UPS technologies differ. There are three UPS technologies available and selection of the most appropriate technology for your application is of vital importance.
Off-line (Standby) UPS's
When mains supply fails, the offline UPS will switch the load across to a battery fed inverter supply (normally with a delay of 4 to 10 milliseconds). When operating from battery power many offline UPS models produce a square wave voltage (also called pseudo sine) which is acceptable for most computer switchmode supplies, but may not be suitable for some loads. These UPS's are designed to protect a single PC or workstation and only offer back up in the event of a total power interruption. They do not incorporate any significant power conditioning.
Line Interactive UPS's
These UPS's are similar in topology to off-line except a voltage regulating circuit is incorporated which boosts the mains power supply when it fails. These UPS's regulate power without the use of a battery during brownouts or surges in the supply voltage and have a sinewave output, enhanced software and connectivity options. They provide a high level of protection at a very affordable price.
Double Conversion (On Line) UPS's
For critical power applications Chase Power recommend true On-Line Double Conversion technology UPS's. These UPS's provide the highest level of protection, usually only required by businesses operating from a server or in industrial applications. For more technical information about the role of the On-Line Double Conversion UPS, contact Chase Power.
How can I be sure what technology the UPS I am considering purchasing is?Chase Power recommend care be taken to check this information to ensure you get what you are shopping for. Don't just read the box it comes in - ask for a technical data sheet. Your supplier can and should be able to provide this.
Caution: Some manufacturers will claim their UPS is Line Interactive UPS, but if you review the technical data sheet you will be able to see for yourself whether the UPS is pseudo sinewave (not a real Line Interactive UPS), sinewave (this is the terminology you would expect to associate with a real Line Interactive UPS) or some other.
UPS SizingTo size your UPS you need to know the VA rating of the connected load.
For sizing phase, VA = Volts x Amps
Example:
Single phase Monitor 240V 1Amp
240 x 1 = 240VA
For 3 phase, kVA = Amps x voltage x 1.73 / 1000
To calculate what size UPS best suits your needs, make a list of the voltage and amperage of all the items you will protect with your UPS. (Monitors, external hard drives, modems, printers etc)
For each item calculate the total using the formula given above, then add up the totals.
Remember to allow for growth. Undoubtedly you have invested a lot of money in your computer system. But somewhere in the future it is likely that you will add additional equipment - a new telephone, external hard drive etc. By over sizing your UPS a little you can add new equipment without having to buy another UPS.
What if I have more questions?Your supplier should be able to answer all of your questions, but if you have any concerns please don't hesitate to contact us on 07 3822 8000 or via email at sales@chasepower.com.au for technical advice.
Chase Power Pty Ltd can offer a huge range of UPS that we supply and support throughout Australia and New Zealand.