What explains a sudden voltage drop to laundry room?

Question

We have a 20 amp circuit running from the service panel to our laundry room, where we have a gas washer and dryer on 120v.

We've not had any problems with the electrical system in our house since we bought it (7 years ago), at which point we upgraded the service panel and had some new circuits runs.

Today, when using the washing machine, it suddenly turned off, and would not turn back on. I went to the service panel - none of breakers had tripped. I manually turned the garage breaker off, then back on, but the washer still would not turn on. Back in the garage I used a multi-meter and found the voltage to be at ~60v (whereas other receptacle in the house correctly report 120v). If I plug in a lamp in that receptacle and turn it on, the light shines, but dimly.

What's going on here? What would explain the sudden voltage drop? It's been years since we've had any electrical work done and it's worked flawlessly until just today. Does this indicate a short somewhere in the wiring? An issue at the service panel?

Thanks

Answer 1

This sounds like a “back stab” problem to me except you said 20 amp and backstabs are only approved for 15 amp circuIt. Current code requires a dedicated circuit. I would expect to find a loose connection or broken wire at the receptacle or in the main panel. If an older home with multiple receptacles on this circuit work backwards to the panel it will be the first not functioning receptacle or the last working one.

What are you looking for? A loose or broken wire at a wire nut or screw since a 20 amp circuit. I usually find them in the receptacle boxes as the wire fill is tight there compared to the main panel, but it can be in the main at the breaker or the neutral buss.

Answer 2

How many outlets do you have on the 20A circuit? And/or what else is running off that circuit?

Assuming the problem is isolated to this circuit, weird voltage drops can indicate that you have a break somewhere in the loop, and you're actually getting "phantom" voltage. Check all your connections and terminations, both Active (Hot) and Neutral, at all outlets, unctions, and terminals on the circuit.

Answer 3

Does it stay at 60v or change as the washer starts? I was at a house and everytime the washer started the voltage would drop to 98volts and the washer would not start then it would go back to 120v. Pg&e changed the meter and it works fine now..