we are having a problem when they pug in a comm. vac. the computers need to boot like they have lost power the computers are on seperate cir from the recepts they are using for the vac. neutrals are not shared on the same cir in question either but they are multiwire cir . they also are share the same panelboard. the ups on the computer doesnt seem to sense the problem which makes us belive there is a noise issue . we are thinking iso xfrmr but would like other sugest. thanks kevin.
There's a couple of things I'm curious about. Are you saying there's a problem with more than 1 computer? If so, are they on the same ups? At the same time? Always? Does the UPS sound an alarm or beep? How many times has this happened? You said they are not on the same multiwire circuit? on I'm just asking these things to get as clear a picture as I can.
Is is a long run from the panel? Never hurts to check tightness of connections.
Any power fluctuation that would affect the computer should be sensed by the UPS first. There could be something wrong with it (ups). If you're talking about 1 computer there could be some problem with it not related to the Vac. Or, you could have a voltage drop problem (for various reasons) and a ups problem.
I would also take a hard look at the equipment grounds from the computer receptacles and the vac receptacles all the way back to the service. A surprising number of computer problems crop up due to grounding problems. Computers reference the equipment ground but the UPS might not.
Please let us know what you find out.
Few things are harder to put up with than the annoyance of a good example.