Service drop vibrating/humming

[aftershock]

I went to a service call today where the customer could hear a humming noise in her bedroom. This noise seemed to be coming from the service drop. The attachment point for the service happens to be at the corner of the house where her bedroom is.

The drop is about 100' from the pole with the transformer. I can grab the wires and feel the vibration. You can hear the humming noise from within the bedroom and also if you place your ear to the outside wall near the attachment point.

The customer also tells me she gets interference through her car radio as well as her radio in the house. I did n ot verify that part. She has had the power company out a few times.

Has it ever been known for a transformer to vibrate at the pole thus sending the vibration through the service drop?

 

[Ragin Cajun]

Put your ear to the power pole. That will either rule it out or nail it.

RC

 

[Sierrasparky]

I would not do that on a rainy. I had a customer complain once that every time they touched the power pole when it was raining they go a tingle. The pole was in the side yard and when they put out the trash they would brush against it. I heard that they replaced the trans and the problem went away.

 

[tesi1]

vibrations

vibrations

ive seen on numorous jobs the poco had pulled the triplex service drop
way to tight, the house had vibrations coming in down the mast, when
discussing the matter with the poco they just blew me off, a couple of
weeks later a car bumped the guy wire on the power pole causing the pole to
lean and put excessive force on the drop, which collapsed the wall of the
house at the bottom inward. the poco showed up the next day added a drop
pole between the house and power pole and paid for the wall & service to be repaired. for some reason the vibrating sound went away ???.

 

[Sierrasparky]

Gee .. mysteriously the vibration went away. That's because we live in a time of great dishonesty were we have no problem lying. We have many examples letting one know it's ok!

 

[jaylectricity]

That's because we live in a time of great dishonesty were we have no problem lying.

I know this is off-topic, but last night I watched a movie called, "The Invention of Lying," and it was a pretty good flick. A lot of well-known actors in the movie, just came out on DVD.

 

[TOOL_5150]

Has it ever been known for a transformer to vibrate at the pole thus sending the vibration through the service drop?

Most definately! I have felt it myself a few times. one time it was so much that it felt like i was getting shocked, and i did the quick "pull away" :grin:

~Matt

 

[SG-1]

My POCO transformer was causing intermittent radio interference and the service voltage was slowly rising. Then one day it blew up. POCO then replaced their transformer & my TV set. And we all lived happily ever after.

I think the radio frequency interference was caused by the windings arcing. The voltage increase was the result of the windings slowly shorting together.

I suppose that if arcing is causing the radio interference that a connection could be getting bad, being pulled apart by the bango string style service drop.

Good Hunting !

 

[mivey]

ive seen on numorous jobs the poco had pulled the triplex service drop way to tight, the house had vibrations coming in down the mast...

Sounds reasonable to me.

Aftershock,
What does the drop look like? Does it look like a banjo string? Have you measured the sag?

 

[mxslick]

Put your ear to the power pole. That will either rule it out or nail it.

RC

Sierrasparky already said it, but I'm gonna repeat it:

DO NOT EVER put your ear or any other body parts against a power pole!! A flaky ground, missing ground, insulator leakage or any other factor could result in you getting a nasty shock.

A safer, but not 100% safe, way to do the listen test is to use a piece of PVC conduit or plastic pole to put to your ear then the other end to the pole.

 

[ty]

bees nest in the wall?

 

[aftershock]

Sounds reasonable to me.

Aftershock,
What does the drop look like? Does it look like a banjo string? Have you measured the sag?

I was able to pull it to me enough to install a new wedge clamp. So not too tight.

 

[TobyD]

I had a call a while back concerning a noisey service entance.I got there and the elderly lady told me she'd been hearing a noise in the attic near her bedroom.After checking the eyebolt nut and washer that was still tight I was listening for the noise and I heard it.What I discovered was a phone drop running overhead that attached to her house.And near the street there was a forked tree limb and the phone line was tight to the fork.As the wind blew the tree limb back and forth the vibration sounded like a animal grunting in the attic.So, now I'm a tree trimmer .Hey I got got paid.LOL

 

[mivey]

I was able to pull it to me enough to install a new wedge clamp. So not too tight.

I would think that the loose cable and attachment would have enough damping to keep the vibration from resonating in the house. Some transformers can certainly vibrate excessively. Have IR'd the transformer, scoped it with an ultrasound, checked the loading? How old is the transformer? Is it wind vibration or does it happen on a calm day?

Sounds like the POCO might need to put forth a little more effort. Maybe with you as her advocate, they will be more likely to listen.