How to Use a UPS

The benefits of a UPS (Uninterrupted Power Supply) are clear. We all need, after all, enough time to save that important report or close that game properly, brownouts or blackouts be damned. Straight from the Tom’s Hardware Forums comes some sound advice.

Courtesy Aspstation.net

• “Never plug any surge suppressor or power strip into the load side of a UPS. [They] can cause the UPS to drain its battery faster than expected, or cause the UPS to shut down or trip a circuit breaker.”
• “Never plug any device into a UPS’s battery-protected outlets that… draws a high amount of power when first turned on. This includes most printers, especially laser printers; the power they draw at start-up exceeds what the UPS can deliver.”
• “[M]ake sure the load doesn’t exceed the UPS’s real or apparent power ratings. Most UPS’s have some type of total load indication or at least an overload indicator light to let you know that the UPS is overloaded.”
• “Different models of UPS may have the same apparent power rating but a different real power rating… UPS designs are different and one can handle more real power than the other. A prime example is the APC Smart-UPS 750 vs. the Smart-UPS 750 XL. Both are rated 750 VA, but the XL model can handle 600W while the non-XL model can only handle 500W.”
• “Different models of UPS may have the same apparent power rating but vastly different run times. The power rating is determined by the size and design of the inverter, while the run time is determined mainly by the battery size. The APC Smart-UPS 750 and Smart-UPS 750XL are both rated at 750VA, but when powering a 300W load, the XL model can run it for over 45 minutes, while the non-XL model has only 10 minutes of run time.”
• “Your computer power supply rating is much greater than the amount of power your system actually draws. Many computers today have a 600W or higher power supply, but actual draw from the line is generally 300W or less, so you don’t need to spend the money on a 1500VA UPS. To find out the actual amount of power your computer is using, use an inexpensive watt meter like the Kill-A-Watt.”