Q: When I buy a 15Amp power strip, why does it say it only provides 12Amps?

A: I understand your confusion and will try to clear it up for you.

The standard power combination in use in the US is 15Amp/120VAC. We like to say the power strips are compatible with 15Amp/110-125VAC because the voltage can vary a little bit without affecting performance.

All power strips are “de-rated” by 80% to ensure you (or any user) does not try to get more out of it than it can supply. The remaining 20% is for things like “in-rush current” that can temporarily cause the power strip to exceed the maximum power available and trip the circuit breaker. For this reason, the maximum steady state power output you should expect to get from a 15Amp power strip is 12Amps (15 x 0.80).

Therefore, the most you should expect to actually use safely is 12Amps.

Until next time, Rackmount Ranger.

This entry was posted on Tuesday, October 21st, 2008 at 4:08 pm and is filed under Ask Rackmount Ranger. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.