I went to do a service call for a local restaurant that complained about their lights dimming when periodically throughout the day. I started at the panel and found that the feeder wires were supplying very close to 120 volts on every phase to ground and nuetral and 205-206 volts between phases.

Further more, all lighting branch circuits are on their own breaker so overloading the circuit is not the issue. Their receiving a 400 amp service which should be sufficient for the equipment they are running.

I am scratching my head as to why their lights are dimming, especially when the dishwasher kicks on, because correct wire gauges were used, correctly sized breakers are used and the voltage coming into the building is pretty much spot on.

Any information to help me with this would be greatly appreciated. This problem really opens up a can of worms because of the potential of so many factors involved.

Hi, imajohnhead!

I moved your question out of the Small Business forum area into this one in the hopes that it will be more likely to get noticed and answered to your satisfaction.

With over 300 subject specific forum areas on Ask Me Help Desk, there are certain forums where certain experts tend to most always answer, and I thought that your question would be better served by placing it in this one.

Thanks!

Most likely there is a loose or bad connection in the feeder system, which can be at the utility pole, utility connections of the aerial or underground feeder, inside the utility meter, or the panel or main breaker.

An electrician and the utility company needs to be on site to check the entire feeder and distribution system.