LesCharles73
New member
- Location
- Dallas, Texas, US
Hey guys,
First post on this forum. I have previously worked as an apprentice and now work as a pyrotechnician. Anyway, my question relates to a recently installed lighting circuit where I work.
Basically, what would cause a 120v 20A circuit to make a loud vibrating noise?
We recently deleted an 8' T12 fluorescent strip in our shop and replaced it with a conduit run of 3 receptacles (approx. 25' total). The receptacles are all evenly spaced, in double-gang metal junction boxes (one outlet each), all pigtailed, 12 gauge solid core THHN wiring. All conduit (both old and new work) is flex. All has been working fine until tonight when I went to turn on the lights.
I flip the switch and instead of lights coming on, I hear a noise that sounds like a power tool running. I immediately turn the switch off and back on and the noise does the same. I look up at the old conduit run and the conduit was vibrating. This was the conduit leading to the j-box that the new addition comes from.
Wondering what in the world is going on, I try it again and the lights come on happily, no noise. I checked the main j-boxes at the ceiling and nothing was hot or anything like that. The wiring we added was simple - just a run of receptacles. The lights added were CFL hi-bays (100w fluorescent).
My first thought was "harmonics", but I don't really know anything about that. Any advice? Should I have our Electrician come back and look at everything? No doubt something isn't quite right - I just can't imagine what.
First post on this forum. I have previously worked as an apprentice and now work as a pyrotechnician. Anyway, my question relates to a recently installed lighting circuit where I work.
Basically, what would cause a 120v 20A circuit to make a loud vibrating noise?
We recently deleted an 8' T12 fluorescent strip in our shop and replaced it with a conduit run of 3 receptacles (approx. 25' total). The receptacles are all evenly spaced, in double-gang metal junction boxes (one outlet each), all pigtailed, 12 gauge solid core THHN wiring. All conduit (both old and new work) is flex. All has been working fine until tonight when I went to turn on the lights.
I flip the switch and instead of lights coming on, I hear a noise that sounds like a power tool running. I immediately turn the switch off and back on and the noise does the same. I look up at the old conduit run and the conduit was vibrating. This was the conduit leading to the j-box that the new addition comes from.
Wondering what in the world is going on, I try it again and the lights come on happily, no noise. I checked the main j-boxes at the ceiling and nothing was hot or anything like that. The wiring we added was simple - just a run of receptacles. The lights added were CFL hi-bays (100w fluorescent).
My first thought was "harmonics", but I don't really know anything about that. Any advice? Should I have our Electrician come back and look at everything? No doubt something isn't quite right - I just can't imagine what.
