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Mike G.
Mike G., Master Electrician
Category: Electrical
Satisfied Customers: 7291
Experience:  Proven Professional 48 years Experience
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I just moved into a rental with brand new seemingly not

Customer Question

I just moved into a rental with brand new seemingly not professionally installed wiring. Beyond a few items of concern, my main question is about the wiring to the washer/dryer. After being ran for about 25min for the very first time the washing machine displayed an error that the repairperson said indicated a faulty or possibly burned out motor. The washing machine plugs into the dryer in a stacked setup. The dryer is wired to a 4 prong outlet on a 30amp breaker that has only the dryer receptacle & a single 1 bulb light on it (as far as I can tell). The wire to the metal box is 12 gauge armored flexible conduit with no ground wire (just black/red hots and a white neutral). The ground wire from the receptaple is a pigtail screwed into the metal box. I tested the receptacle with a multimeter the wires are on the correct places. The hot to hot reads 208v. The hots to neutral each read 122v. The neutral to ground reads .004v. I've noticed other outlets/non transformer plugs seeming warm to the touch and I noticed one that looks to have been burned.
1. Is it likely that the wiring caused the damage to washing machine motor? Or is it just a fluke or manufacturer defect? In other words will the new one meet the same fate?
2. If the wiring is the issue how do I determine the cause? Is the cause undersized wire? If its undersized why didnt the breaker trip? Is something else wrong besides no ground, 12g wire?
3. Would installing GF protection help this issue?
Thank you
Submitted: 7 months ago.
Category: Electrical
Expert:  Mike G. replied 7 months ago.

Hi, I'm Mike G and I'll be assisting you. The issues as I see from your description are as follows.

  1. The circuit should be #10 wire on a 30A 2 pole breaker
  2. The neutral and ground connect together by code exception for a pre-existing laundry circuit.
  3. Failure of a receptacle and plug is caused by loose jaws on the receptacle. Over time it arcs and the condition gets worst until you can see the burned connection.

Replace the receptacle, connect the ground to the box and the white wire. Installing a GFCI would be a good idea, but not required on a 240V circuit.

Customer: replied 7 months ago.
I agree on point 1 and it IS on a 2 pole 30A breaker but undersized at 12g wire. My question is 1- could this be the reason the motor on the washing machine burned out and 2- will it happen again 3- whats the solution.
Customer: replied 7 months ago.
On points 2&3 seems like you missed the part when I said this is all brand new wiring & receptacle and appliance. Brand New. Never used. Not worn out.
Customer: replied 7 months ago.
Also wiring all over the house which again is BRAND NEW is warm to to the touch. Is this related to the other problem? How do I troubleshoot this problem when you can for sure rule out old worn out receptacles or miswired receptacles at least in terms of showing up correctly on a tester (hot neutral ground in correct places).
Expert:  Mike G. replied 7 months ago.

I suggest opening the panel and testing each breaker to the neutral bar for 120V per breaker. Then turn off all the branch circuit breakers and test phase to phase on the incoming wire and then each phase to the neutral connection. While doing the tests look for any signs of arcing or discoloration by heat. Test the bus's phase to phase and each phase to neutral. Let me know the readings.

Customer: replied 7 months ago.
Ok I can try that tomorrow. But still curious could undersized wire cause a washing motor to burn up?
Customer: replied 7 months ago.
washing machine
Expert:  Mike G. replied 7 months ago.

Loose connection arcing will produce low voltage which will fail a motor. The burnt outlet is the evidence.

Customer: replied 7 months ago.
possibly a loose connection at the breaker? The burnt outlet I saw was 2 floors up on a different circuit.
Expert:  Mike G. replied 7 months ago.

Very possible. Even new wiring can fail due to failure to tighten connections. Bad connection cause low voltage. Voltage drops, amperage increases. A 30A breaker would hold and not trip on a stackable washer dryer.

Customer: replied 7 months ago.
Would a bad connection show up in meter readings at the receptacle?
Expert:  Mike G. replied 7 months ago.

It would if on the circuit ahead of the outlet. If it is the device having loose jaws, the burnt outlet is self evident. Just test the panel as instructed to eliminate a service connection or failing breaker or breaker connection. Come back with the results. You need to test not guess.

Customer: replied 7 months ago.
Ok. I'll write them to you tomorrow.
Customer: replied 7 months ago.
Thanks
Expert:  Mike G. replied 7 months ago.

You're welcome.

Customer: replied 7 months ago.
Each breaker to neutral bar: 123v. Phase to phase off breakers: all were 123v with the exception of 1 half of the double pole 30A breaker in question which read 121. Also got 121 from adjacent 20A breakers. No signs of discoloration, burning, or loose connections. Bus to bus: 210v, Bus to neutral: 123v
Expert:  Mike G. replied 7 months ago.

You gave me buss to buss 210V, what is lug to lug on the main breaker?

Customer: replied 7 months ago.
With further exploration I discovered the 30A dryer breaker is wired from the panel to a light switch junction box with 10g wire (no ground) then is spliced to 12g wire where it runs to a light fixture. There are 2 groups of 12g leaving the box but I cant be sure the line runs directly to the dryer outlet box without opening up the fixture.
Customer: replied 7 months ago.
Also 210v
Expert:  Mike G. replied 7 months ago.

Somewhat lower than expected but having 123V phase to neutral is good. Everything considered the failure must have been at the device. To burn it was either a loose wire connection or a loose jaw on the device. Both would cause a low voltage that would affect the washer/dryer motor.

Customer: replied 7 months ago.
Well it was the device (and not the washing machine itself) is there a way to definitively isolate the receptacle device as the problem?
Customer: replied 7 months ago.
IF it was...
Expert:  Mike G. replied 7 months ago.

The burnt device is the evidence of the cause.

Expert:  Mike G. replied 7 months ago.

A short circuit in the appliance would have tripped the breaker before it burnt the device.

Customer: replied 7 months ago.
The burnt outlet I mentioned before is not the dryer receptacle its just a random outlet on another floor that has nothing to do with this except that it gave me pause as to the quality of work done in the house.
Customer: replied 7 months ago.
The receptacle connected to the washer/dryer is brand new and at least from my eye undamaged and working properly.
Expert:  Mike G. replied 7 months ago.

Sorry I forgot about that. No matter. The appliance may have had an issue that failed the motor. The readings at the panel were acceptable though low phase to phase. It should have been closer to 240V. Not explainable having g 123V at phase to neutral. If you look at the nameplate rating on the appliance you'll see it's operating voltage which I'm sure is more than 210V. Low voltage results in high amperage. High amperage will heat and fail electrical items.

Customer: replied 7 months ago.
Is there anything I can do to isolate the problem further?
Customer: replied 7 months ago.
If it was a fluke with the washing machine itself then fine I guess. But I dont want another $1000 wiring mistake in the form of another burned out machine.
Expert:  Mike G. replied 7 months ago.

Retest at the panel. Phase to phase down in the lugs not on the lugs to see if there is a difference.

Expert:  Mike G. replied 7 months ago.

Also test phase to phase on the 2 pole 30A breaker.

Customer: replied 7 months ago.
Still reading about 210 (it'll jump to 211 or 212 at first) for both phase to phase readings regardless of whether it tested on lugs or in them/on wire.
Expert:  Mike G. replied 7 months ago.

I suggest calling the utility and having them test their distribution voltages. Having 210V is low. Did you look at the name plate on the appliance. I'm sure it requires a higher voltage. By code a combined voltage drop of 5℅ is the maximum.

Customer: replied 7 months ago.
Noticed signs of long term water and wetness around the pull box opened it see below:
Customer: replied 7 months ago.
pull box
Customer: replied 7 months ago.
Heres the panel
Customer: replied 7 months ago.
Ok good to know. This is Brooklyn and everything is a million years old.
Expert:  Mike G. replied 7 months ago.

The bug connection on the right looks to have possible issue from the picture. Is the tape melted?

Customer: replied 7 months ago.
Washing machine says 208-240V ~60hz 12A
Expert:  Mike G. replied 7 months ago.

Listed at a minimum of 208V, you're OK.

Customer: replied 7 months ago.
Ok.
Customer: replied 7 months ago.
Tape is not melted. Everything is cool/not warm.
Expert:  Mike G. replied 7 months ago.

The only thing I can say is the burned outlet and the appliance motor failure were coincidental and not related. The voltage reading are OK within acceptable readings. The 210V is what an electrician would expect on a 3 phase phase to phase service. Single phase usually reads over 220V phase to phase.

There isn't any more I can add.

Customer: replied 7 months ago.
Should the washer/dryer be rewired with a 10g dedicated line before the new one goes in or is the current setup acceptable?
Customer: replied 7 months ago.
Is it possible that under load the voltage is dropping under 208?
Expert:  Mike G. replied 7 months ago.

Fluctuation on the utility distribution may drop the voltage at certain times of day depending on area demands.