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View Full Version : Lost half my zones, no breakers tripped, can turn back on zones by turning on my oven


will6000
Nov 24, 2015, 10:51 PM
I was attempting to fix a wall sconse. It worked when I bought the house but stopped shortly later. I fixed what appeared to be an old loose wire, and upon hitting the switch power went off in about a third of the zones in the house.


Now I've tried to figure out the cause of this because no breakers were tripped when it happened. I used a volt meter and tested the legs to the house and the one reads 120v when I test it with the ground wire.


Now here's where it gets weird. My 220v oven when set to broil will cause the lights to come back on in parts of the house though the volt meter reads that they're only getting about 94v. I can control several lights by using my oven dials.

hkstroud
Nov 25, 2015, 04:43 AM
You have lost one of the two hot leads coming into the house. What is happening is really not weird. When you turn on the oven, which is connected to both hots, power passes through the element from one hot to the other.

First try resetting the main breaker. That's not likely to be the problem but try anyway.

If you feel competent, remove the panel cover and do a voltage check between the lugs of the service entrance cable. Should read 240V between lugs and 120V between each lug and the ground or neutral.

Then call power company.

Missouri Bound
Nov 26, 2015, 07:02 AM
"and tested the legs to the house and one reads 120v"
What about the other one? You need two 120v legs for a complete service (at least).
You found your problem... now you need to find out what caused it.
Call the power company.

hfcarson
Nov 27, 2015, 08:27 AM
This is a symptom of what happens when you lose the neutral, either in a circuit or the main service. Immediately call a licensed electrician to investigate. This condition can cause significant damage if it has not already....
Please write back and let us know what you found out!

Stratmando
Dec 4, 2015, 11:05 AM
Tempted to believe 1 Hot was lost as well. A Breaker may have been tripped, but not thrown. A Bad breaker, Burnt or corroded buss could do as well.
You need to test for not just 120 volts to Ground/Neutral, but for 240 volts between the 2 hots. This is probably fixed by now.

Ran into a strange one one time, Owner said they heard a loud POW, everything went off, then Back on except 240 Volt stuff. I had 120 volts off each hotleg at the Panel, But Zero volts between the 2 hots(should have been 240 volts), Went to outside Disconnect and had 240 volts between both legs, I told owner somehow it appears that the 2 hots between the Disconnect and the panel have fused together and blew open 1 leg coming from the disconnect, but were joined together in the underground aluminum conduit. Had an LB at ground level, And had to use a Heavy Duty Utility Truck to pull the Conductors out which had also melted to the Conduit. That was strange.
If a hot leg is lost, you may still see 120 volts one each leg, but zero between the 2.
Curious what was the result. Take Care