Strange APC-650 UPS reaction

[JG]

Hello !

My computer is connected to a brand new APC 650-CA Battery Backup/Surge
Protect unit.

Upon installation, I tested the unit by "pulling the plug" and got a
message saying I had 15 mins left before automatic shutdown. Fine.

Today, I plugged my vacuum cleaner in an outlet located in the same
circuit than my APC.

Upon starting my VC, the computer immediately felt into sleep mode.

When I pressed a key to awake it, I had a message saying something like
"You must immediately plug your computer on DC or you'll loose data"
(translated from french).

It happened at least three times - and I verified that each time the
computer felt into sleep mode as soon as I powered my vacuum cleaner.

Besides saying its because the VC is 13 years old and maybe needing be
replaced.. can someone explain why the PC felt into sleep mode instead
of the APC just taking over ?

Thanks..

PS: I'm on Win XP Pro - SP2.

 

[CBFalconer]

.... snip ...

Besides saying its because the VC is 13 years old and maybe needing
be replaced.. can someone explain why the PC felt into sleep mode
instead of the APC just taking over ?

When vacuum cleaners (or other motors) start they draw heavy surge
currents. Normally after startup some sort of centrifugal switch
disconnects the start up windings, and the result is a large
inductive noise surge. This is apparently both inadequately
suppressed at the VC, and the PC supply has inadequate input power
noise suppression.

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