Purpose of the UPS
The Absolute Limits – VA & W
Sine Wave, Square Wave and Co.
Your UPS will have a Surge protected side and a Battery backed side. Your computer and monitor goes in the battery side so they’ll have power when there’s a black out. Your laser printer must NEVER go into the battery side since it draws too much power and will drain the battery flat
For that matter, anything that drains a lot of power should never go on the battery side. This includes space heaters, photocopiers, hair driers, appliances, etc.
Even if the devices you use are reasonable, fight the temptation to plug in everything into the battery side. Plug in only what is absolutely necessary (i.e., the computer, the screen and the switch if there’s one).
UPS Best Practices
You don’t have to test every week but it would be worth checking up on the UPS every other month or three to make sure nothing has gone wrong in the meantime. Someone may have plugged in a space heater unbeknownst to you and drained the battery sufficiently that it no longer hold much of a charge.
You will need to connect the provided USB cable as well. The software will automatically shutdown/hibernate your computer when the power goes out. This is invaluable for if you’re not at your desk when the power goes out.
Even if you’re lucky, the battery in your UPS will need to be replace at around 3 years. If your battery gets triggered often, whether because of brownouts or blackouts, the battery life-expectancy will plummet (down to almost no battery time after a year in some cases!). Some UPS software packages will warn when to replace the battery but regular testing is the best way to be sure.
You can calculate the minimum VA requirement by multiplying the current rating by the voltage (typically 120V). So a 5A device would need at least 600VA. It won’t need it continuously but only at its absolute peak.
It is probably better to aim for the Power (W) rating instead (the VA rating generally is much higher) because power factors are rarely as bad as 0.6. If your electronics draw up to 300W, then look for a 600W UPS.