Hubbell GFCI’s humming after Service upgrade

Went out to a client’s house today to troubleshoot some bathroom GFCI’s that she said were humming intermittently. She said it had only started in the last few weeks, which unfortunately coincides with a 600amp service (pedestal about 10ft from the house) upgrade we just did to the house.

The service upgrade is its own culmination of a nightmare: separate old service feeding a pool equipment shed turned out to be minus a neutral (thanks to a direct bury service entrance conductor having failed), which I only realized after my guys hooked up the owner’s new $20k hot tub with every bell and whistle you could imagine. We quoted a price to run the pool equipment panel back to the main house service, which I understood from my 2nd failed inspection on this project (the first missing the open neutral on the old 200amp service for the pool), to be pedestal CT service which I assumed had the rings actually installed in the pad mount underground fed transformer. Unfortunately the rings were in the 400amp pedestal (which didn’t look big enough in my opinion to be a 400amp CT). So the project turned into another unexpected change order of combing the house and pool feeds into a 600amp rack mounted free standing CT service. Long story short we were done, hoping to get paid when she can afford, having already giving a full discount for the $1500 project for the hot tub hookup that originally brought us to this project.

Back to my problem now... couldn’t find any issues with the GFCI’s and they never hummed while I was there. The 200amp Seimens panels were part of a full home rewire that done when she purchased a 1960’s architect designed “mid-century modern” single level ranch of sorts. One bathroom was a kids bath on one end of the house and the other was in the master. Both had a 12-2 nm feed supplying only the bath receptacle circuit for that bathroom. The master bath had a single 20amp Hubbell GFCI that was somehow non-tamper (not sure how that passed inspection). The other bath had (2) outlets, one load sided from another 20amp Hubbell GFCI that was again non-TR, my only consternation on this one was that there were two 12-2’s off the load side of the GFCI but I could only find one load side receptacle. Voltages were 122v at the outlets and I believe 122/241 or so at both panels. Replaced both GFCI’s with Leviton 15amp tamper with self test (realized later I screwed up on the Master Bath, should have been a 20amp). Most of the GFCI required circuits were protected in the panels with breakers and she didn’t mention any issues with them. The one other bath (a powder bath had a Leviton 20amp GFCI outlet with non-tamper once again) she said she hadn’t heard any humming from. Hoping I solved the problem by replacing the outlets, but curious as to whether others have run into similar conundrums with GFCI’s that I am told were working fine until the service upgrade?
 

retirede

Senior Member
Location
Illinois
I’ve never heard (or heard of ) GFCI receptacles humming. I’d suspect another source (especially since you weren’t able to observe it) - older fluorescent light nearby, by any chance?

Just a question: Why do you feel the Bathroom receptacle needs to 20 A?
 

hillbilly1

Senior Member
Location
Atlanta,Ga
I suppose the trip solenoid could hum. Long read, so I don’t know if it has been replaced, or swapped to another location. Maybe failed circuitry sending ac to a dc coil.
 

growler

Senior Member
Location
Atlanta,GA
I suppose the trip solenoid could hum. Long read, so I don’t know if it has been replaced, or swapped to another location. Maybe failed circuitry sending ac to a dc coil.
The way I look at something like this is it's cheaper just to replace 2 or 3 GFCI receptacles while you are there than it is to make another trip. Even if there was nothing wrong this will probably make the customer happy. That way you can move on to bigger and better things.
 

Fred B

Senior Member
Location
Richfield Springs, NY
Occupation
Electrician
The way I look at something like this is it's cheaper just to replace 2 or 3 GFCI receptacles while you are there than it is to make another trip. Even if there was nothing wrong this will probably make the customer happy. That way you can move on to bigger and better things.
That's fine as long as humming doesn't come back, if it does, you have a customer that feels cheated. OP indicated he didn't observe the humming, thus any throwing parts at it without clearly identifying the cause, could create a customer getting angry over feeling cheated. Perhaps changing the item identified by the customer as the offending device would be warranted with the caveat that confirmation of problem at that time not possible as event not replicable. And that future visit may be needed and if problem does not reoccur, great it's fixed.
It would be interesting to know if the device was the cause, take it with you and set it up on a test bench and operate over time to see if you can replicate the humming. If so you might be able to get warranty replacement device.
 
I’ve never heard (or heard of ) GFCI receptacles humming. I’d suspect another source (especially since you weren’t able to observe it) - older fluorescent light nearby, by any chance?

Just a question: Why do you feel the Bathroom receptacle needs to 20 A?
The house was completely remodeled in 2008, so everything is generally up to date. I wondered if it was some other noise but she said it happened in both bathrooms, and they had different layouts with different vanity lights. However I did no further investigation of other possible sources of noise, if she calls me back out, I will take a closer look around.

I figured only one outlet on a circuit requires it to match the ampacity of the breaker.
 
Sorry for the long post, most of it was just off loading my grievances as to how a project can rapidly snowball into a money pit/disaster.

I changed the outlets, and hope that solved the problem. Definitely ready to be done with this project.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Just a question: Why do you feel the Bathroom receptacle needs to 20 A?
I would say that’s smart work.
I wouldn’t do a bathroom less than 20 amps.
new hairdryer and a curling iron at the same time is over 15 amps
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I would say that’s smart work.
I wouldn’t do a bathroom less than 20 amps.
new hairdryer and a curling iron at the same time is over 15 amps
15a and 20a receptacles of a given grade have the same internal parts.
 

rambojoe

Senior Member
Location
phoenix az
"Same" is a broad stroke...bust one of each open and make sure, because they are not.
One dead give away is one feels like pushing a prong into butter, and one feels like plugging into a block of cheese....
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
"Same" is a broad stroke...bust one of each open and make sure, because they are not.
One dead give away is one feels like pushing a prong into butter, and one feels like plugging into a block of cheese....
They are the same and the 15A is rated for 20A pass through. Only difference is the slots on the 20A. What you might be referring to is the difference between contractor and spec grade.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I would say that’s smart work.
I wouldn’t do a bathroom less than 20 amps.
new hairdryer and a curling iron at the same time is over 15 amps
Have you ever seen a hair dryer or curling iron with a 20A plug?

Yes, I like to provide baths with a 20A dedicated circuit too but there is no reason you can't or shouldn't use 15A duplex receptacles.

-Hal
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Have you ever seen a hair dryer or curling iron with a 20A plug?

Yes, I like to provide baths with a 20A dedicated circuit too but there is no reason you can't or shouldn't use 15A duplex receptacles.

-Hal
Whoops...:oops:
I was on a 20 amp circuit...
Not a 20 amp plug.
 
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