What the hell is that noise (in my lights)!?

[PCustoms]

Alright here's a weird on for you. Just went down to the shop to kill the lights and radio after dinner.

Light circuit is 15A breaker from my main panel feeding 14/2 to a 3 bank switch box. Back left switch feeds a GFCI and 3 downstream outlets. Back right bank is a mirror image. The front is a gfci and 3 downstream outlets. All lights are loads are as follows:

Back left: 6 LED fixtures, all on
Back right: 2 T12 fixtures, on. Jet air filter plugged in but off
Front: 6 LED fixtures, all on.

Killed the radio (that outlet is of a 60a sub panel), then walked back to the door and flipped the front lights off, then the back left, then heard a horrendous "GRRRRRRRRRR" before I shut the back right off. Went away as soon as I shut it off, didn't come back when I turned it on. If I turn the back left on, then back right on, then back left off "GRRRRRRRRRR”.

WTF. Only time I've ever heard something like that was a short on a 277v light circuit, and only until it melted enough of the wire to cause a dead short.

Only me home and I can't isolate it and flip the switch, so I start unplugging things and trying again, both back banks on, back left off and listen for the noise. After a few rounds in isolate it to the jet air filter, which is nothing more then a small control board and a squirrel cage fan. And it hasn't been on in a week.

WTF.

Now I think it is a locked rotor sound. But the damn thing is OFF, and it only does in when as I turn the other bank off. What sort of weird issue or stray voltage could I have going on?

EDIT: see down below, over a year later and it happened again. I have isolated it to the Jet air filter and the blower is running about 1/2 speed with all indicators and the control OFF.

 

[Captain Spaulding]

Maybe a neutral problem. Are both light banks on the same breaker or same side of panel?

 

[PCustoms]

Maybe a neutral problem. Are both light banks on the same breaker or same side of panel?

Yes, all 3 banks are on the same breaker.

 

[PCustoms]

Any ideas?

Going to pull the switches this morn and confirm the neutral, but haven't wrapped my head around how that could be the issue with this this is wired.

Also going to get a meter on the outlet. The air cleaner is likely just a symptom of the issue, as it's been off.

 

[Terry D]

So the switches work receptacles that the lights and the air filter are plugged into?

Is there a way you can unplug the LED's and see if it still happens

Has this been working normally and now just started doing this.

Is this wiring a new install?

So you are saying that the air filter is making a noise or hum when it is turned off.

 

[PCustoms]

So the switches work receptacles that the lights and the air filter are plugged into?

Yes, it was a handy outlet for the hanging unit.

there a way you can unplug the LED's and see if it still happens

I did not unplug them all, but I did have the 2 T12 fixtures unplugged from that bank, the front bank was off.

I have a separate circuit with a couple screw in LED bulbs, I can use that and unplug everything to try again.

Has this been working normally and now just started doing this.

Is this wiring a new install?

Not new, probably been installed for 3 years now. Never had this happen before, but this is the least used light bank, as it's in a corner.

So you are saying that the air filter is making a noise or hum when it is turned off.

Correct. Haven't run it since last weekend. When I killed the lights in sequence (front bank, back left, then back right where the air filter is plugged in) it was immediately evident some was wrong. Only thing plugged in is the filter, boise. Unplug the filter, no noise. But it's OFF.....

 

[PCustoms]

Ok, so I just failed troubleshooting 101. ALWAYS restore a test to the original conditions and confirm the defect before testing a new idea. I did not, so I'm not sure if the problem was still there this morning.

What I did do: plugged my GFCI tester into the outlet in question, yep, wired correctly. For the hell of it I pushed the test button on the tester, and the GFCI upstream tripped. I reset it, plugged everything in and repeated my sequence from last night, all is quiet.

:

 

[PCustoms]

Well didn't find anything yesterday.

Possibly adding to to puzzle, I noticed last week I had a cheap fixture (one of those 2 for $10 home depot LED kits) flickering. Figured it was just a bad light given how cheap they were and no other lights in that circuit were doing it. This is only a totally different breaker (will need to see if it's on the same leg as the shop overhead).

Took the dog out this morning and that light was working fine.

 

[PCustoms]

Alright it's back....

Kicked up some dust in the shop and I had the air cleaner set to a 2hr cycle (it has a timer). I shut the other 2 light banks off and left the shop.

About 3hrs later I went to check things and noticed the cleaner was making noise, squirrel cage was turning about 1/4 speed but the unit was off.

Turning the unit on makes it start fine and spin full speed. As soon as I turn it off it barely spins and makes noise.

If I turn the other light bank on, it stops.

 

[kylefitz]

Alright it's back....

Kicked up some dust in the shop and I had the air cleaner set to a 2hr cycle (it has a timer). I shut the other 2 light banks off and left the shop.

About 3hrs later I went to check things and noticed the cleaner was making noise, squirrel cage was turning about 1/4 speed but the unit was off.

Turning the unit on makes it start fine and spin full speed. As soon as I turn it off it barely spins and makes noise.

If I turn the other light bank on, it stops.

Sounds like something is failing on the filter control board. I would try to plug it into a different circuit, possibly using an extension cord. That would more or less eliminate the lighting circuit.

 

[BillK]

Maybe a neutral problem. Are both light banks on the same breaker or same side of panel?

I was going to say the same thing. Either that or a switch failing and doing something stupid. Unplug the filter and see what voltage you have at the socket with the lights off.

 

[PCustoms]

I was going to say the same thing. Either that or a switch failing and doing something stupid. Unplug the filter and see what voltage you have at the socket with the lights off.

Well with the lights off (switch off) it was zero....

Checks across all combinations and didn't see any odd readings. Voltage was 121.#, at the outlet off the panel it was 122.#.

But it wasn't buzzing (running half speed with the control off) today.

Super odd that the filter was trying to run, at half speed, but would stop as soon as I turned the other bank on.

 

[Fly YX]

Check for loose or corroded connections on the lugs. Is this an older install on the panel are the ground and neutral tied together?

 

[PCustoms]

Check for loose or corroded connections on the lugs. Is this an older install on the panel are the ground and neutral tied together?

Entire house has been rewired in the past 5 years. Neutral and ground are bonded at the main panel that this feeds from. Nothing loose so far, no odd voltages at the outlet.

 

[WillyBoy]

I have something similar to this

Jet 1000CFM Air Filtration System with Remote

This powerful unit is perfect for the smaller home shop!

www.rockler.com

hanging from my basement shop ceiling. Operating with the remote makes it really handy but I've had the same thing happen with the fan.

I read somewhere that the IR receiver in the fan housing is/can be sensitive to fluorescent or LED lights in the area.
One solution is to replace all the shop lights with incandescent bulbs. Since my entire basement is 6500 K LEDs I don't want to do this.
The receptacle next to the filter has nothing else plugged into it so switching the receptacle doesn't affect anything else in the shop.
I wired a switch into the wire going to the fan receptacle and leave it flipped off most of the time. When I need the fan, I reach up, flip the switch, and then use the remote to start the fan and set the timer for the run time I want. Later on when the fan has shut off, I go back downstairs and flip the switch off if the fan is growling.
Yeah, it's an extra step (two, actually) but it saves getting the step stool out and unplugging the fan each time. This problem didn't start immediately, it was 6 months + -, before it started.

I haven't heard about any solution that corrects the problem other than changing out the receiver circuitry and hoping for a new board that only sees the remote, not the ambient lighting.

 

[PCustoms]

^^^^i wonder if it is related to the remote.

The only time I use the remote is to activate the timer, otherwise I just reach up and turn the filter on. The remote is Velcro'd to the table saw switch with the IR emitter pointed up.