Plugging a surge protector into a UPS battery backup

jrichrds

Platinum Member
Oct 9, 1999
2,537
3
81
The manuals that come with my UPS battery backups say not to plug a surge protector into the UPS. Does anyone know the technical reason for why they say not to do this?

I currently have a few low power devices plugged into a surge protector strip, which is then plugged into a UPS battery backup. And it seems to work fine on battery mode. I'm basically using the surge protector strip as an extension cord with additional outlets, and like the ability to switch off those devices separately from the other devices plugged directly into the UPS.

Moved to appropriate forum - Moderator Rubycon
 

Blain

Lifer
Oct 9, 1999
23,643
3
81

A Tripp-Lite tech explained it to me many months ago. If I remember correctly...
The surge strip can send some kind of signal back down the line and kill the UPS.
 

pcgeek11

Lifer
Jun 12, 2005
22,100
4,886
136
A UPS provides the surge protection on the input side of the circuit so plugging a UPS into a surge protector is the same as daisy chaining surge protectors. Due to the potential for harmonics and feed back into each others surge protection circuits one or both could blow up causing a fireworks show and or a fire.

The output of a UPS is usually a square wave and not a sine wave. Surge protector circuits are designed for a sine wave input. Unless the surge protector is designed for a square wave and even then I would take it with a grain of salt.

best bet = don't ever do it.

pcgeek11