Line fault at the outlet -- do I need an electrician?

Yesterday, I got a Panamax, Max 1500 surge protector and line conditioner. (I got a very good deal on it, and am just trying it out.)

I plugged it into an outlet I've been using for a while and one of the red lights on the front lit up saying "line fault." (I'm not sure how this is different from a "ground fault." Maybe it's the same.) The Panamax does not do this with other outlets in the room. They seem ok.

So, I know this means that the outlet is improperly wired. My question is, might this be a simple thing to check and/or fix? Any suggestions most appreciated. It's the only outlet I can use to have my audio set up where I usually have it. Now is not an optimal time to call an electrician. If this is a big problem, I'll try out my gear somewhere else in the room, but if I can fix this without too much expertise, that would be ideal.
8700e65e 845e 4b1b 91cc df27687f9454hilde45
hilde45 OP303 posts


The 4v issue is weird, because the multimeter does not read 4v on a properly wired outlet on a different circuit.
Apple to oranges, imo.
What is the wire gauge size of the other branch circuit? What is the total length of the branch circuit? What is the total connected load on the circuit? What is the type of devices that are connected to the circuit? How many CFL and or LED lights are connected to the branch circuit? What is the voltage drop on the circuit that you didn’t measured the 4V neutral to ground voltage?

You have all kinds of things going on with the branch circuit where the wall outlets have reversed polarity issues. You now know the branch circuit feeds outlets on the first floor and the basement. You now know it feeds ceiling lighting. How many CFL and or LED lights? They spew all kinds of harmonic noise back on the AC mains. Who knows what that does to your cheap multimeter.

There is still a very good chance the 4V is caused by voltage drop. Now that you know the branch circuit feeds outlets and ceiling lighting on the first floor, not just the basement, turn off all the connected loads that are connected to the branch circuit. Check for the neutral to ground voltage again. No load, no voltage drop.

As for the power conditioner showing an AC mains ’Line Fault’ condition. Correcting the AC polarity reversal problem, will solve the power conditioner 'Line Fault' problem.

Got it. All those are good questions, but I think the ultimate solution is to delegate this whole thing. But now I know what to ask the professionals. This amateur is sticking with writing and teaching. Thanks again.
"I remeasured the outlet. Here are the readings that I got:
Ground to neutral slot equals 121.6ground to hot slot equals 3.6
neutral to hot equals 124.6Hot to neutral equals 124.6"
- Hot to Neutral 124.6   (let's call Hot - Line .. more typical term)
- Ground to Neutral Slot 121.6- Ground to Line Slot 3.6
I assume this measurement was made with almost everything turned off?
Hot-Neutral is 124.6 ... or about the same as Ground-Neutral + Ground-Line.  With a noise-free reading, (G/N) + (G/L) should approximately equal the source voltage at your electrical panel AND and should be higher than what you measure L-N at the outlet.

(G/N) + (G/L) = 125.2 - Or perhaps the voltage at the panel(L-N) = 124.6 - Or the voltage after all the drop(G/N) + (G/L) - (L-N) = 0.6

However, as stated G-N should be close to 0, but often is not due to drops in the wires (and noisy measurements). Given you have 3.6 with what appears a very small drop on L-N, that suggests either a noisy measurement (possible), OR, it could be a faulty ground connection on that line. Given the wiring issue already noted (and DIY nature), I would be investigating the ground integrity. Fortunately, you can do this yourself.

1) Turn the breaker off!!2) Wait 30 seconds (any leakage from capacitors in power supplies)3) Ensure the L-N, G-L and G-N voltage is 0.  I am expecting G-N is 0, but if it is not really close with power disconnected, that is an interesting result. If it is no 0 or really close, DO NOT CONTINUE!
4) Repeat step 3! ... you really need to be sure.5) Put your multi-meter on the ohms setting.6) Measure the resistance between the Ground and the Neutral (the ones that was measuring 3.6 volts). It should be <1 ohm with a good contact between the probes and the socket.
Thanks for that process. It sounds like this test does not require me taking the outlet out --just testing the ohms with the multimeter. That doesn't seem very unsafe, but I'll follow instructions carefully if I do it.

Your circuit is fed from a sub panel, correct?  Is the circuit fed from an independent breaker, or is it a duplex?

Also, have you seen any boxes in  between the sub panel and the outlet?