House woes

R

RoyB

Member
Location
Chicago
Occupation
Electrical Contractor
Hey all, looking for some input on some weird things going on at my house. I am an electrical contractor/owner by trade, and was in the field for 15 years prior. I think I am pretty good at troubleshooting but some of the stuff going on at my house have me stumped.

Basics:
  • House built in 1979
  • House has 200A Service
  • Whole house generator (20kw), service feeds through transfer switch. All connections are tight.
  • Service Feeder is approx 325' ( I need to confirm wire size)
  • Most of the house is on Lutron Radio Ra3 and LED lamps. If LED lamps are used, I set to reverse phase.
  • We moved in a little over a year ago and I have rewired 80% of the house.
  • Wiring is in conduit system.
Troubles:
  • Some lights flicker/dim when the Washing machine runs. They dim with every rotation of the tub/agitator. The can lights seem OK for the most part (Soraa lamps), but the Chandelier and Island pendants are affect (screw in lamps). The entire kitchen lighting is on a dedicated circuit.
  • All lights dim when the well pump kicks on. Not sure if this is normal, I've never had a well pump before. 15/2 circuit.
  • Get a slight flicker in kitchen cans when they are dimmed low and dryer is running (240v).
  • Lights would dim when AC's would go on. I put on Soft Starts and that pretty much eliminated that issue. Haven't ran AC since Octoberish so I am not positive now since it's been 4 months and some of the flickering was cause by other issues.
  • Some areas I haven't rewired yet, the lights flicker or dim down/up.
  • I noticed most of the issues in the kitchen when we are there for dinner. Sometimes oven is on (electric) but I don't think that's the problem since it also happens when the oven is off. I have the whole kitchen on a 70a or 80a subpanel since I ran out of space in main panel.
  • Undercabinet lights would dim if there were loads on the same phase elsewhere in the house. This was pretty much fixed by running a dedicated lighting circuit. It seemed to dim on 1 phase more than another, so I moved to another phase. The house is pretty balanced this so makes no sense to me.

I need to confirm feeder size, but would an undersized feeder be causing all these issues? For the distance, I think it should be around 250-300mcm. In real world, I don't think I am ever drawing over 100a when these issues arise (dryer, oven, etc).

There's no water ground because there's no water service. Not sure if there's a ground at the meter, I need to confirm. There's no ground next to the meter (it's now in a mud room), but there may be one in the meter. I thought there was a ground wire in the panel , but now that I am thinking about it, it could have been for one of the other sub panels.

MOST of these issues presented themselves after changing to LED lamps. This makes me think maybe there's a polarity issue somewhere. 98% of the fixtures have been changed in the house. Some of them were wired backwards. After re-wiring, it fixed most of the issues, but some still persist.

Tonight I'll check incoming conductor size and see if I can figure out the grounding. In the mean time, is there something obvious I am missing?
 
Are you using less expensive dimmer switches? I have had those cause flickering before.

I don't think the feeder size has anything to do with it.
 
Have you tried to screw in a incandescent bulb into the screw shell lights that are experiencing flickering?
 
Probably just how LEDs are interacting with newer appliances. I see this more and more as variable frequency drives are added to more equipment in the home. This was so bad at a commercial place with chandeliers that I installed a double conversion online UPS on the lighting circuits just to keep them from rapidly flickering when the heat pumps were running.

We are in a new frontier where brand new technologies are coming online simultaneously and no one foresaw how they would interact.
 
LEDs are more sensitive to changes in AC waveform. The cheaper LEDs utilize cheap materials or skip out on some of the smoothing and extra electronics to make it more resilient to fluctuations.

Motors create disturbances on the waveforms. If the appliance is newer and manufactured out of the country (like Samsung or LG) then you could have a VFD motor which more notably disturb voltage waveforms.

My suggestion are

1) increase wire sizes on branch circuits or feeders affected. The less voltage drop you have, the lower the likelihood a small disturbance or dip due the the washer running will effect the LED.
2) buy more expensive LEDs and see if the issue persists. A type that is WIFI controlled might also help since their internals aren't as sloppily thrown together.
 
Cursitti said:
Have you tried to screw in a incandescent bulb into the screw shell lights that are experiencing flickering?
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Not recently, I don't have left.

CoolWill said:
Probably just how LEDs are interacting with newer appliances. I see this more and more as variable frequency drives are added to more equipment in the home. This was so bad at a commercial place with chandeliers that I installed a double conversion online UPS on the lighting circuits just to keep them from rapidly flickering when the heat pumps were running.

We are in a new frontier where brand new technologies are coming online simultaneously and no one foresaw how they would interact.
Click to expand...
We had a restaurant that would flicker a bunch of chandeliers. Only one area in the whole place. We couldn't figure it out, ended up going back to incandescents to fix it.

ptonsparky said:
What are you voltage readings at the panel? Line to line, line to neutral. Simultaneously if you can. No load then with washer, well.
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I didn't check yesterday, but when troubleshooting other stuff voltage was always in normal ranges.

Elect117 said:
LEDs are more sensitive to changes in AC waveform. The cheaper LEDs utilize cheap materials or skip out on some of the smoothing and extra electronics to make it more resilient to fluctuations.

Motors create disturbances on the waveforms. If the appliance is newer and manufactured out of the country (like Samsung or LG) then you could have a VFD motor which more notably disturb voltage waveforms.

My suggestion are

1) increase wire sizes on branch circuits or feeders affected. The less voltage drop you have, the lower the likelihood a small disturbance or dip due the the washer running will effect the LED.
2) buy more expensive LEDs and see if the issue persists. A type that is WIFI controlled might also help since their internals aren't as sloppily thrown together.
Click to expand...

The Soraas are generally ok ($$$). The screw ins are mostly Satco which are still a good lamp. I might try a different brand to compare. The Washer/dryer are LG, we purchased them when we moved in last year.
 
Did a little looking around last night.
  • Wiring in the panel is 2/0 cu
  • Wiring on load side of meter is 3/0 cu
    • I know they butt-spliced when they extended into ATS but I didn't follow that closely to see if they changed wiring in the spice
  • Line side of meter is 3/0 or 4/0 aluminum. 4/0 lugs but wire size looks the same as the 3/0.
  • There is no earth ground
  • There is no water ground
  • There is a wire on the Neutral that looks like it goes back to the transformer. Would the power company bond at my meter and run back to their transformer? I've never seen this before.
  • The panel Neutral/ground bond is removed and laying in the bottom of the panel.
    • They bonded the neutral to the ground in the ATS (first point so this make sense), but there is no earth/water ground as noted above.
I think the Line side should probably be 300-400 aluminum because of the distance. However, I don't think I am ever drawing over 110A at any given time. Even with the dryer, both ACs, and oven going. I don't think the size of the wiring is the issue, possibly no ground or/and issue in poco transformer?


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You may not be drawing over 110A steady-state, but when things like the well pump and AC start up, you will momentarily exceed that, perhaps by quite a bit, which will cause a momentary voltage drop that will definitely affect the LEDs.
 
retirede said:
You may not be drawing over 110A steady-state, but when things like the well pump and AC start up, you will momentarily exceed that, perhaps by quite a bit, which will cause a momentary voltage drop that will definitely affect the LEDs.
Click to expand...

The soft starts on the ACs reduced inrush from 75A to 29A. That made a pretty significant difference on the lights dimming on startup. I should check the well pump inrush to see what it draws. OCP at 15 amps, it's likely 3/4 or 1hp. Inrush probably around 40-50 amps I bet. Maybe I can run it through a UPS? Maybe capacitors getting tired?
 
ptonsparky said:
Normal range isn’t good enough for LED. Sudden changes in the voltage will be noticeable by the flicker.
Click to expand...

Some lights flicker (randomly or when washer is going). This is different than lights dimming under startup load. I have both issues. The startup dim makes sense and working to resolve. The flicker I can't figure out.
 
RoyB said:
Some lights flicker (randomly or when washer is going). This is different than lights dimming under startup load. I have both issues. The startup dim makes sense and working to resolve. The flicker I can't figure out.
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Fix the one and you will be closer to the second.

Your set up isn't that much different than mine other than I have a VFD on the well and No dimming on the LEDs. All electric and only load on the POCO transformer.
 
RoyB said:
Some lights flicker (randomly or when washer is going). This is different than lights dimming under startup load. I have both issues. The startup dim makes sense and working to resolve. The flicker I can't figure out.
Click to expand...

LEDs flicker on sags when old incandescent would dim.

LEDs utilize electronics to modulate the AC waveform to a DC current driver with rectifiers. As the waveform gets distorted, the field in the nonlinear components won't stay in the correct bias and cut out. Frequencies within the normal 60Hz (referred to as harmonic distortions) and voltage sags are the normal culprits.

It is not a simple issue to correct since the effects can be reduced based on larger branch circuit wire sizes. The lower the impedance of the circuit, the lower the effects other loads have on creating sags (current rises momentarily, voltage drop increases as a V = IR loss on the wire). It isn't always measurable on normal measurement tools since it happens quickly.

Sometimes installing a metering device that can capture waveforms can help narrow down the culprit creating the disturbances but won't always provide a clear or simple fix.
 
RoyB said:
Some lights flicker (randomly or when washer is going). This is different than lights dimming under startup load. I have both issues. The startup dim makes sense and working to resolve. The flicker I can't figure out.
Click to expand...
Just curious, "some lights" your washer is 120v, so the lights that flicker, are they on the same phase or the other phase, or both?
 
RoyB said:
I know they butt-spliced when they extended into ATS but I didn't follow that closely to see if they changed wiring in the spice
Click to expand...
Based on the quality of the neutral lug job I would be suspicious of those 'butt-splices' in the service entrance conductors.
I would replace the meter base and pull new service entrance conductors from the ATS to the meter.
 
A little dimming when a load kicks on is normal and has always existed. Some of it can be mitigated by increasing the conductor size at the service, but it is often due to voltage drop across the utility transformer itself.

But LED flicker is caused by appliances that rapidly switch on and off, like new direct drive washers and inverter heat pumps. PWM heating in new ovens is also something I noticed causing flicker. We're in a perfect storm of brand new technologies that don't play well with each other and no one is sure who is to blame.
 
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