I have a residential house with a 200 amp service. Customer is complaining about lights flickering in the house. No other houses in the neighborhood have this problem. The lights that are flickering are on numerous circuits, of which none of those circuits have any motors, such as fridges or freezers on them. My first step was to check the panel and tighten everything down. When that didn't work I went to each individual light and checked the sockets and tab in the sockets and actural rewired an old hanging kitchen light. Still no fix. My next step is to pull the meter and check connections there and at the weather head, which I did see are bugged and not crimped. Any other suggestions?
Stumped
- Thread starter derease
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hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
use a peak reading DVM, damper-ed meters will not act fast enough to see it, and check the voltage at the meter each leg to neutral, and move in from there till you see it, if you determine it's before the service call the POCO, after keep going till you find it. rent a recorder or ask the POCO to put one on the meter, I have had to do this many of time because of Murphy's law, it just never does it while were there lol.
I had a bad neutral crimp at the transformer once, the voltage fluctuation was so fast the POCO service man couldn't see it with his Fluke set to RMS voltage, my Amp Probe meter which has a peak setting would barely, so it took several calls to get the POCO to fix it, they saw the problem after they used a recording meter in the meter socket.
I had a bad neutral crimp at the transformer once, the voltage fluctuation was so fast the POCO service man couldn't see it with his Fluke set to RMS voltage, my Amp Probe meter which has a peak setting would barely, so it took several calls to get the POCO to fix it, they saw the problem after they used a recording meter in the meter socket.
K8MHZ
Senior Member
- Occupation
- Electrician
Neutral connection from the POCO to the residence?
Connect an analog meter from one leg to neutral and watch the meter when the lights flicker. Do that on both sides. If either side exceeds line to neutral voltage I would suspect a neutral problem.
If the voltage only drops, I would expect a poor line connection coming into the residence.
In order to put the blame on the POCO these readings will have to be re-created on the line side of the meter. That being said, I have seen bad connections in the meter sockets as well.
Be careful taking readings on live systems. Don't use cheap meters. I have a friend that had one go boom on him. Analog meters are tough to come by but the digital meters (except scope meters) aren't fast enough for such testing. Old Triplett and Simplex meters are the cat's meow for check for dithering.
A scope meter is better, though, but very pricey.
Connect an analog meter from one leg to neutral and watch the meter when the lights flicker. Do that on both sides. If either side exceeds line to neutral voltage I would suspect a neutral problem.
If the voltage only drops, I would expect a poor line connection coming into the residence.
In order to put the blame on the POCO these readings will have to be re-created on the line side of the meter. That being said, I have seen bad connections in the meter sockets as well.
Be careful taking readings on live systems. Don't use cheap meters. I have a friend that had one go boom on him. Analog meters are tough to come by but the digital meters (except scope meters) aren't fast enough for such testing. Old Triplett and Simplex meters are the cat's meow for check for dithering.
A scope meter is better, though, but very pricey.
electricalperson
Senior Member
- Location
- massachusetts
you have a loose phase. check the burndys and meter
Cow
Senior Member
- Location
- Eastern Oregon
- Occupation
- Electrician
Is it dimming or flickering?
One's not uncommon, the other is a potential fire hazard.
One's not uncommon, the other is a potential fire hazard.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
090819-2038 EST
At the main panel, preferably thru unloaded breakers, connect a 50 W bulb to one phase, and another 50 W bulb to the other phase.
When the flickering or dimming occurs what do these lights do? If one goes bright and one dim, then a neutral problem. If nothing happens, then the problem is in other breakers or wiring. If both lights dim, then the problem is likely a 240 load in the referenced house or a neighbor's, or it would have to be from the transformer primary side.
Any neighbors on this same transformer should see the problem if it relates to voltage changes at the transformer.
Note: that impulse dimming is not easily seen with CFLs compared to incandescent.
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At the main panel, preferably thru unloaded breakers, connect a 50 W bulb to one phase, and another 50 W bulb to the other phase.
When the flickering or dimming occurs what do these lights do? If one goes bright and one dim, then a neutral problem. If nothing happens, then the problem is in other breakers or wiring. If both lights dim, then the problem is likely a 240 load in the referenced house or a neighbor's, or it would have to be from the transformer primary side.
Any neighbors on this same transformer should see the problem if it relates to voltage changes at the transformer.
Note: that impulse dimming is not easily seen with CFLs compared to incandescent.
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gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
090820-1045 EST
A definition of the customer's use of flickering is needed.
From dictionary.com
A momentary dimming or brightening from the turn on of a high inrush device, or a step function change in intensity from a large continuous load may be describe by some as flickering, but more correctly probably should be called a transient change.
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A definition of the customer's use of flickering is needed.
From dictionary.com
A momentary dimming or brightening from the turn on of a high inrush device, or a step function change in intensity from a large continuous load may be describe by some as flickering, but more correctly probably should be called a transient change.
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wptski
Senior Member
- Location
- Warren, MI
K8MHZ
Senior Member
- Occupation
- Electrician
Is the complainant a woman?
Do the lights flicker when she gets stressed?
Perhaps this is what is happenning:
http://www.dailymail.co.uk/news/art...wers-causes-lights-flicker-gets-stressed.html
But seriously, women tend to notice flickering that men can't see.
[Voice of Experience] Be cautious about attempting to solve a problem you can't duplicate. [/Voice of Experience]
Do the lights flicker when she gets stressed?
Perhaps this is what is happenning:
http://www.dailymail.co.uk/news/art...wers-causes-lights-flicker-gets-stressed.html
But seriously, women tend to notice flickering that men can't see.
[Voice of Experience] Be cautious about attempting to solve a problem you can't duplicate. [/Voice of Experience]
ELA
Senior Member
- Occupation
- Electrical Test Engineer
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Get calls from the big box stores all the time, their UPS units go into overload for regular, short periods of time, 99% of the time somebody plugged a laser printer into "clean power", They draw 10-15 amps for a couple of seconds at regular intervals while idling.
The flickering does sound like an arcing connection somewhere, could be the main going bad, do a FOP test.
The flickering does sound like an arcing connection somewhere, could be the main going bad, do a FOP test.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
090821-0701 EST
My HP 5SI MX has an initial warm up current of about 9 A.
After warm up and not printing about 4.5 A for 5 sec and 0.6 A for 20 sec.
At the point where I measured the current and voltage the change from 4.5 to 0.6 A produced about 3 V change, 0.6 ohms source impedance.
This voltage change produces a side vision detectable intensity change in a 100 W bulb.
0.6 ohms is equivalent to about 180 ft of #12 Romex.
Recently I looked at the cycling of an electric frying pan. Temperature setting 350 deg. This was operated with nothing in the pan. Initial heating time about 130 sec. Initial current 10 A, and at temperature 9.8 A. Steady state period about 10 seconds on and 20 to 25 sec off.
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My HP 5SI MX has an initial warm up current of about 9 A.
After warm up and not printing about 4.5 A for 5 sec and 0.6 A for 20 sec.
At the point where I measured the current and voltage the change from 4.5 to 0.6 A produced about 3 V change, 0.6 ohms source impedance.
This voltage change produces a side vision detectable intensity change in a 100 W bulb.
0.6 ohms is equivalent to about 180 ft of #12 Romex.
Recently I looked at the cycling of an electric frying pan. Temperature setting 350 deg. This was operated with nothing in the pan. Initial heating time about 130 sec. Initial current 10 A, and at temperature 9.8 A. Steady state period about 10 seconds on and 20 to 25 sec off.
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wptski
Senior Member
- Location
- Warren, MI
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
In a galaxy far, far away.
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