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jparrie
11-19-2008, 09:50 AM
I just finished wiring my new home from the ground up. I am having issues with lamps flickering at times very minor, other times more severe. I define minor as a half a second or less in duration, severe as one to two seconds of dimming. I had a licensed electrician come and check my work before the rough electrical inspection, which passed without violations.

I suspect that the problem may be with the new overhead drop from the street that PG&E put in. I have come to this conclusion for the following reasons.

1. The lamps that are affected are all on odd numbered breakers. Lamps on even numbered breakers seem rock solid.

2. This holds true for circuits that are connected to the main breaker panel, and circuits that are connected to the upstairs subpanel.

3. I have checked all connections at both panels for proper torque, all are good.

4. I used the can lights that are now flickering for general lighting during construction, and cannot recall ever noticing any flickering. At that time, the structure was being fed from a temp service pole. After inspection, PG&E ran a new drop of larger service wire to the structure.

I suspect that there is a flakey connection on one phase of the hot either at the weatherhead or at the pole. Is there something I can do to confirm this, or should I just call PG&E out to have a look?

All suggestions appreciated.

Thatguy
11-19-2008, 11:02 AM
having issues with lamps flickering at times very minor, other times more severe.
Bad connection or heavy current draw or both
as a half a second or less in duration, severe as one to two seconds of dimming.
A motor starting with very high starting current; maybe it's about to fail.
passed without violations.
Something must have slipped past this inspection. . .?
I suspect that the problem may be with the new overhead drop from the street that PG&E put in. I have come to this conclusion for the following reasons.

1. The lamps that are affected are all on odd numbered breakers. Lamps on even numbered breakers seem rock solid.
Bad connection or heavy current draw or both
Rock solid may mean the incoming line is good, or you don't have high startup currents on these lines.
2. This holds true for circuits that are connected to the main breaker panel, and circuits that are connected to the upstairs subpanel.
Problem is upstream of these two.
3. I have checked all connections at both panels for proper torque, all are good.
You can also check with a voltmeter across the connection while current is being drawn. The drop should be much less than 30 millivolts.

4. I used the can lights that are now flickering for general lighting during construction, and cannot recall ever noticing any flickering. At that time, the structure was being fed from a temp service pole. After inspection, PG&E ran a new drop of larger service wire to the structure.

I suspect that there is a flakey connection on one phase of the hot either at the weatherhead or at the pole. Is there something I can do to confirm this, or should I just call PG&E out to have a look?

All suggestions appreciated.

Watch for arc-flash if you mess with conductors that have no upstream fuses/breakers.
Incand. lamp brightness is very sensitive to applied voltage. You might check some outlets with a voltmeter. A normal outlet should drop 2 or 3 volts when you switch on a 10A load (a hair dryer or toaster).

Johnny C
11-19-2008, 11:40 AM
Turn the lights on and off in different room and notice if there is any change in brilliance either dimming or getting brighter, if this happens, it could be a faulty connection to the neutral conductor either at the panelboard, service drop at the house, or at service pole or transformer. What your describe appears to be a faulty connection by the utility, since you have checked your connections. How about checking the connections in the meter enclosure. Good luck. It took a burned up TV for me to convince the power co.that they had a neutral splice that wasn't crimped at the house service drop.

220/221
11-19-2008, 12:22 PM
just call PG&E out to have a look.

Tell the field guy what you have observed and have him do a load test.