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View Full Version : 120/208? Confused on wall outlet voltage


dwarrenku
Aug 16, 2010, 07:48 AM
I just moved into a new apartment building. When I plugged in my subwoofer, it started to pop every 10 seconds, something that it hadn't ever done before.

I took out the multimeter and measured the voltage coming from the outlet, assuming that this may be what was causing the pop, and the voltage was ~200. I went all around the apartment, and measured each outlet the same way, one probe in each slot, and everything is reading ~200 volts.

I'm assuming that this is because we're on a 120/208 3 phase system, but is the voltage supposed to be this high :confused:?? I thought it was only supposed to be 208 when you wanted it to be, not on every outlet. I'm beginning to be worried about the electrical equipment in the apartment now, and I'd like to have more information before going to the landlord.

dwarrenku
Aug 16, 2010, 11:46 AM
I take back my previous assumption that I'm on a 120/208 phase 3 system. All outlets are the standard 110 volt receptacle, but 200 volts are coming out of them. Anyone have advice or help?

KISS
Aug 16, 2010, 11:49 AM
Either your meter is bad or something else is wrong, A standard light bulb should be extremely bright and possibly blow.

dwarrenku
Aug 16, 2010, 11:59 AM
Either your meter is bad or something else is wrong, A standard light bulb should be extremely bright and possibly blow.

I suppose I'll go and get another meter just to be sure, but I know that I've used this multimeter in my last apartment and found the voltage to be normal (around 120). But really, if things are setup correctly, there's no reason the meter should be reading 200, right?

KISS
Aug 16, 2010, 01:00 PM
Correct.

Check all voltages:

L to N = 120
L to Gnd = 120
Gnd to N ~ 0

Remember, it's sometimes difficult to put probes in the outlets.

Also, there are new outlets which are designed with safety in mind where both sides of the outlets must have a plug in them.