OT....house electric question

A strange one for me....when an appliance with a motor turns on, the lights in the house get bright for a second! Not the usual dimming. Also, my 15 amp radial saw will not get up to speed. Any ideas? Voltage checks out normal. Thanks.

Sounds to me like a grounding problem. I would check the main ground at the breaker box. May have a bad connection there.

Sounds like you could passably have a lose connection in your plug in and its back feeding,,??????

(quoted from post at 14:54:37 01/08/10) A strange one for me....when an appliance with a motor turns on, the lights in the house get bright for a second! Not the usual dimming. Also, my 15 amp radial saw will not get up to speed. Any ideas? Voltage checks out normal. Thanks.

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eutral connection problem. At the extreme of no neutral connection, the 240 volts across the transformer secondary will divide according to load, with the larger part of the 240 appearing across the lesser load (lights instead of motor). Ought to find & fix, because under the particular set of conditions, you could end up with excess voltage on some 120 device & ruin it.

Neutral problem. check the main lugs CAREFULLY as the shock from a neutral is by far the most dangerous in 120/240 volt.

Had wind storm several summers ago. Had a lady with electrical problems. Spent several hours-could not find anything inside-checked her service line at the pole-one of the hot had come undone. Very hard to figure some of this stuff out-BE CAREFUL! Greg

If anybody says a grounding problem, don't listen. The neutral carries current, the ground only carries current during faults.
It could be a simple as just VD on the neutral of say 10 volts will make the loads on the other line where the motor isn't starting.It will see 130V instead of 120V.

V D veneral disease???? Sorry slow day ... I do respect your advice. Not fair that our mutual friend JOHN T is missing all this cold weather

mother-in-law lost their neutral in there house a few years back . the voltage would go from 10 volts to 200 on the same outlet. you may have a bad neutral poll and it doesn't have to be in the box theirs was about 15 feet from the house in the underground wiring.

VD=Voltage Drop.

Way back when I practiced engineering at our Naval facility I saw a loose/corroded/burned Neutral ( a GrounDED conductr NOT the equipment GroundING conductor) cause similar problems. Id check each n every Neutral connection first thing.

Its been on the cool side down here in Florida also, but yesterday and today we were out in the sunshine in long sleeves or a light jacket.

Keep warm yall

John T

Had the same problem this year ended up being loose neutral lug on the trasformer.

Dustin IL

As others said, a neutral problem. Check to see if it does it for the whole house or just for one or more breakers or if it applies just to one side of the buss bar or one of the neutral bars in the main box.

Whole house could be the main lugs or the meter or the transformer for which you would want to call the power company. Ask your neighbors if they have that problem which would point to a transformer.

Take the appliance with a motor and/or the radial arm saw around to plug ins on other circuits to see what result you get. May have to get a lamp to plug in and kick breakers off to determine which plugin goes with a breaker.

Unless you are experienced with electrical panels, you should hire an electrician.

If you can get it down to a particular circuit breaker, then you have to check all the connections. First unplug any lamps to see if that changes it. Could be one of the old receptacles with stab in connections that went bad and then you need to replace all receptacles with ones with screw terminals. Could be a broken or loose wire under a wire nut. My first choice would be a light or lamp with maybe to high a wattage bulb for the lamp holder. They get very hot and begin melting the wiring and a partially melted through neutral would act like that. Walmart carries those replacement lamp holders for a reason cause they go bad all the time. Also make sure someone didn't replace a lampholder or receptacle and switch the neutral and hot wires around(wrong polarity). The next step would be to burn through, cause a fire, and burn your house down and it could happen anytime the frig or heater kicks on and possibly while you are gone or asleep. Have you got smoke detectors and fire escapes and fire drills for the kids?

Another problem is where aluminum and copper wiring is mixed. Those connections loosen up on their own. Do you have any aluminum wiring or receptacles?

Every day the paper has a new house fire. Often by some heating device. A 1500 watt space heater could pull enough current to cause a surge through that bad neutral to burn through and take your house with it.

Look for any wire end that has a black burn spot.

Let us know what you find. And do something soon so I don't read about your family in the paper. Don't mean to scare you here but power surges are serious business.

You have a poor connection in the neutral somewhere ,dont wait to repair it. your 110v circuits can go up to 240 volts and burn up things especially electronic devices.