Charles U Farley wrote:

Wes wrote in
:


The dsl modem in the house was being powered by 121 volts at the time
I checked and is pluggged into a Isobar 6 that is suppled by an off
line ups.

I have read some cautions to having a quality surge suppressor connected to
the output of a UPS. Good suppressors have noise filtering circuits that
could be severely taxed by the spikes and DC components of a non "pure or
true" sine wave UPS output.
I checked the manual for the Isobar and it doesn't have any UPS related
warning but for the simple swapping of pulgs it seems pretty simple to
change and be safer than sorry. A $5 power bar will suffice downstream of
the UPS if you need the extra outlets.

Most UPSes do not want to have surge suppressers downstream from them,
when MOVs downstream clamp on a bit of spike that got through before the
UPS switched to inverter, they blow the inverter.