Loosing my mind

[derease]

I have a customer who told me his lights in his house were flickering. Since then I have been their about 4 times. I did see the lights flicker last time, like a candle in the wind. Anyway, the lights are on about 4 different circuits in a Cutler Hammer CH 200 amp panel. What I have done so far:
switch breakers around to determine it wasn't a breaker problem. Check reading out of meter each line to neutral (124 on each leg). No motor load on any of the circuits in question. Load in panel is balanced, tightened all connections in panel. I am going to go through everything on one of the circuits to see if it will clear up the circuit, I'm starting to think maybe the main could be bad. It doesn't make any sound and I don't want to put a new main in if it is not the problem, I'm just running out of ideas. It's copper romex through out the house. Could a motor load on other circuit (not lights) effect the lights (such as fridge). Help!

 

[mivey]

A motor might but I would not think it would look like a candle in the wind. Sounds like arcing or fault. With a PQ scope you could compare the voltage and current waveform to determine if it was up stream or downstream.

Without a PQ scope, I would IR the main, meter, and svc.

Are other customers on the same transformer having the same problem?

Are the flickering lights resticted to one side of the supply or the other? If the four circuits are all of the lighting circuits they would be the only ones showing the evidence. When swapping the breakers, did you make sure the four were on different poles?

You could check the vdrop across the main and pull it to look for hot spots. I would also pull the meter to check the connection there.

Speaking of candle in the wind, the service conductor could have bad spots as well as a bad connection at the transformer and wind would move the conductors and could cause a flicker.

 

[shepelec]

If it happens at a particular time of day. it could be POCO tap changers on the power banks. Around here it is usually 6am, 12pm and 6pm.

 

[kwired]

If you suspect weak connection someplace (main breaker as you mentioned or meter, POCO connection, etc. connect a fairly heavy load or turn on several loads to load the service to a point that is fairly high compared to what it normally sees and watch the voltage. If there is a connection issue it will show itself under load - the higher the load the faster you will notice it.

ADD:

If the bad connection is in the neutral you will need to make sure you do not have balanced loads or the neutral will not be loaded enough to cause the problem.

 

[charlietuna]

I had a similar problem at a friend's house -- turned out to be an overloaded Power Company transformer. At peak periods is when his lights would flicker due to voltage drop. We put a data logger on his service and showed the Power Company and they came and upsized the transformer--ended problem ?

 

[pnelspec]

If you notice severe flickering it is most probably coming from some significant and fast changing load in the area.
If it was a weak connection, it would most likely be burned in flames already.
If your client doesn't have anything significant which can make severe flicker, such as welding, crashing, lifting, punching etc? so it is most likely coming from some neighbor.
To pin point the problem's source scientifically, you'll need a PQ device which can show/record flicker, voltage and current simultaneously. And then, you check if the current (your client) is changes significantly with the voltage changes while the flicker is high. BTW, visible flicker should show above 1 PST in value.
If you don?t have a proper meter, you can just check with neighbors if they're suffering from the same, and if they're ? complain to local utility and they will do the investigation job.
Good Luck.

Pol

 

[LawnGuyLandSparky]

My home is fed from a pole pig 2 poles away. It's fed from a 3-phase primary that unfortunately, also feeds the LIRR MTA and a school designated as as emergency evacuation center and the VA hospital. Not really "unfortunately" because whenever the lines go down, they're the first to get fixed.

Even after hurricane Gloria and Bell, was only w/o power for no more than 25 minutes. That said, the MTA is now employing electric track switch heater and no longer uses gas... I can see this in my lighting when the temps drop to the 30's...

Maybe nothing wrong here...

 

[derease]

Thanks for the advise. The neighbors do not have this problem. I did notice that his service drop is not crimped by power company, but I did check the lugs. I have PPL here and it is difficult to get them out if you can't show a problem (eg. different reads to neutral). The lights flickering are one both phases and do have receptacles mixed in, but no motor loads on those circuits.

 

[mikkel1]

Flickering Lights

Flickering Lights

Derease, I had a friend that was having problems with flickering, dimming, very bright lights and his well pump not working at times, I used a recording meter for both voltage and amperage after checking all connections from the meter thru to the load side of the breakers, really could not not find a significant voltage problem. I then used a Agema 570 infrared camera on all connections from the meter thru the to load side of breakers, still no problem. As I was following the service back to the utility transformer (overhead service), I found that the utility butt splice to the weatherhead was warmer that the two phases. Called the utility, they came out and agreed that what looked like a good joint was actually not and weather/wind was effecting the service. They cut it out and installed a different connector, problem solved. A lineman friend also points out that the utilities commonly have smaller wire on their transmission lines and services then you'd size by code, due to "open air", and that a large load coming on down the road can cause dimming due to voltage drop.

 

[gar]

100319-1729 EST

derease:

Apparently this is a consistent flickering. Meaning at nearly any time of day you see the flickering.

Also when you say flicker like a candle this implies a loose connection somewhere.

Get two 15 W incandescent bulbs, a pair of sockets, and appropriate test leads. At the main panel connect these to two breakers such that one light is on one phase and the second light on the other phase. Does the flickering occur here. If so put your meter probes on the incoming wires, not the lugs. Look at L1 to N, L2 to N, and L1 to L2. Does the meter show any movement correlating with the flicker. For reference I can detect between 1 and 2 V changes to an incandescent bulb. The reason for 15 W bulbs is to make it easier on your eyes.

If flickering and corresponding meter changes occur at the main panel and if in particular the voltage is changing on the actual supply lines, then much of the problem is probably from the power company.

.

 

[mcclary's electrical]

Do you do a fall of potential test accross main?