mythbusting: surge protection better when off than on?

[BillP]

Hello...I was wondering if anyone could weigh in on this suspected myth. Some folks at my office feel that immediately following a power outage, all UPSes should be turned off to better protect from a surge when power is restored. Is this true? Does that On/Off switch effect the surge protection in anyway? Quieting the beeping is one thing, but this just sounds like a myth to me. Thanks in advance for your input.

[Anonymous user · Accepted solution]

There is no surge protection benefit to turning the UPS off after a power outage, and waiting for power to return before turning it on. Either way, the UPS is going to do the same thing - flip the power path to battery when input power goes out, and flip it back to the online operation when power comes back (or when you manually turn it back on).

However, depending on what UPS models you have, you might want to turn them off so stop the on battery beep alarm if the power is going to be out for a long time, and you don't want to listen to it.

[BillP]

Dirtfoot is correct, in that by turning the unit off prior to utility power returning, there is no benefit to the units surge protection. The solid state components used in surge protection are not controled by the on/off switch and are always protecting the attached equipment, as long as it's plugged into the wall.

If you are concerned that a surge may cause damage to your surge strip once utility power is returned, you may temporarliy unplug the surge arrest from utility, however this is really not necessary.

[BillP]

Thanks for the responses, and for confirming what I suspected. Unplugging makes total sense (if really paranoid), as well as turning them off (if the beeping is annoying).