Unusual service call

[chattahoochee electrical]

I was called to a house today for a humming sound in a single room on the main floor. The homeowner told me that the noise started 2 days ago. The noise starts and stops about every 15 minutes. I opened the 20 amp. breaker feeding the room and the noise stopped. To me it sounds like a noisy light ballast but there are no florescent fixtures in the house. The noise is strongest in one wall. I also checked in the attic and basement, you could hear the noise but it is very faint. Info on the house : built in the forty's, plaster walls and ceilings and armored cable wiring with the old cloth insulation. Has anyone ran across this before?

 

[shepelec]

I had a similar call once also, "humming in the walls".

Found a 15amp breaker with a 14.6A load but nothing was plugged in on the circuit.
Old BX feeding up into ceiling and changing over to K+T some where.

Turns out the K+T went to a kitchen ceiling fixture that had a BX sw leg down to a 3 gang box. Two other sw legs left that box and went to the attached barn.

The K+T shorted to the BX sw leg, followed the armor down to the 3 gang box then followed the other BX out into the barn where it crossed over a totaly seperate BX that was hot to the touch.

Talk about a high resistance short. Took me about 2 hrs to figure that one out.

 

[chattahoochee electrical]

unusual service call

unusual service call

Thanks for the info, The armored cable shorting was what I thought might be happening, I will be returning to the home to try to isolate the circuit.

 

[LarryFine]

First thought: a noisy hidden transformer.

Arcing connection, probably at a receptacle.

Check for HVAC equipment in attic and/or crawl.

 

[220/221]

I had a similar call a few years ago but my post got deleted for inappropriate content. The homeowner had simply left one of her appliances running.

 

[ceb58]

Use a drinking glass on the Wall to try and pin point the noise, a stethoscope would be nice. If you can pin point it in the wall look around the area for switches or recpt.. Also put ans amp meter on the circ. and see what it is pulling. If its pulling high and you have the noise then chances are there is a short in that area.

 

[brantmacga]

I had a similar call a few years ago but my post got deleted for inappropriate content. The homeowner had simply left one of her appliances running.

sweet baby Jesus. I remember a service call when I was a wee apprentice where a young lady had me check something in her bedroom. She forgot about the 400 or so prophylactic's on the floor and tried to hurredly kick them under the bed as i walked in. she struck me as the type of chick that knows how to get down.





and also, you may want to check . . . .

 

[wirenuter]

Leave it off until you figure it out. remove devices startying at the end of the circuit until you find it. Bet its a buried box.

 

[480sparky]

I've done a similar service call and it was a pager set to vibrate.

 

[masterinbama]

Resistive heat buried in the plaster will make a buzzing noise.

 

[Benton]

I had a similar call a few years ago but my post got deleted for inappropriate content. The homeowner had simply left one of her appliances running.

That's funny and not surprising.

 

[Speedskater]

Last Fall, I had a buzzing in a interior wall at home. It seemed late in the year for bees and it was an interior wall. Turns out that the 3 year old Grand-kid was pushing the doorbell that morning and the button was stuck half-on, so it was the chime (doorbell) solenoid that was buzzing.

 

[bullheimer]

BBBZZZZZZZZZZZZZZZZZZZZZZZ!
or not.
Not THIS house, but.... me and two home owners narrowed the noise to a point in the middle of a downstairs bathroom wall. i cut many holes and never even found any electric wires in the bays anywhere!!! good thing i had those two witnesses saying it 'had to be there' or i would have had to pay to fix the holes. there was loose wires upstairs in the bottom of a wall about 7 feet away from the place we thought the noise was strongest!!! three or four bays over too. there had been a fire in an outlet box up there by the time i found it. anyway DONT TRUST YOUR EARS! sorry, i dont have any other suggestions.

 

[fireryan]

Ive worked in houses where a switch runs a contactor for the room lighting. I guess this was a big thing back in the day to have this setup. Ive seen the contactors mounted in the attic and on top of the switch box in these older homes

 

[220/221]

I've done a similar service call and it was a pager set to vibrate.

I found a pocket mini cassette voice recoder that was left in the record position. When it reached the end of the tape it sounded a high pitched warning signal. It was buried in a cardboard box under some clothes which muffled it.

Homeowner couldn't pinpoint it. I couldn't pinpoint it at first. I unpluged everything in the area (home office). I even climbed into the attic because it kind of sounded like it was coming from there.

I ended up on my hands and knees crawling around the room where I found the box with a bunch of crap in it.

 

[Chamuit]

Found a 1000w transformer in a flat top house once doing demo. Moved it into a nearby cabinet when we re-installed. The heat must have been incredible in the summer.

 

[shepelec]

Sure would be nice...

Sure would be nice...

Sure would be nice if the OP let us know what the final outcome was.