kmp567
DIY
So this is a long one..
The other night my dehumidifier turned on and suddenly everything in 2/3rds of the house began cycling on/off and the lights that were on started strobing as well (led bulbs btw). I unplugged everything and reset the breakers, even though none were tripped. At this point, I was able to turn the lights on but they were dim and got dimmer with each new one switched on. The outlets would only power a night light.
After a lot of searching, I came to realize I had a MWBC. Nothing in the panel was labeled when I bought the house, so I figured all the circuits out. When it was all said and done, I had two 15's (one black wire to one leg, one red to the other), and two 20's (same config.). Everything else could be accounted for. The two 20's do nothing with the cb switched on or off but they do all have 120 coming from the breaker. One of the 15's will turn the utility and kitchen lights on and the other powers the bath, hall, beds, and porch lights. Also, noteworthy is the fact that the utility and kitchen lights are perfectly fine and they supply some voltage to the other lights as well, when both breakers are switched on.
The multimeter shows about .4 volts hot and .2 volts neutral starting from the first outlet and moving around the house until I get to the 3rd bedroom (these are the last 2 outlets) ..I say that because the last one only has one hot and one neutral. These 2 have about .8 volts hot and .4 at neutral.
I should add that there are some weird things that affect the lights being able to turn on. If I plug a night light into the first 3 outlets, I can switch all the beds and hall on.. but when I turn the bath light on, the other rooms go dark. If I don't use a nightlight in the outlet and instead turn on the back porch light.. the beds, hall, and bath can all be turned on at the same time. And if I turn on the carport light, it even gets a little brighter, but not so bright that it would blow the bulbs. Btw, the back porch light is controlled by the 15a that controls the beds and bath but it's in the same box as the kitchen lightswitch.. and both those switches show 1.4 volts.
I read that it could be an open neutral but I've been in every switch, outlet, and ceiling light and there's nothing that looks or smells burnt or broken. I also checked the neutrals at the panel. The other strange thing is that the outlet where the dehumidifier was plugged in doesn't let me switch the lights on when I plug a night light into it.. all the subsequent outlets don't as well. That made me think that was the most likely outlet where the damage would be.
I used a wire tracer from that outlet to the next and it doesn't seem like there's a break. Plus there's a little voltage going to all the outlets.. none are dead. But that voltage is definitely coming from the 15's and not the 20's, as it should be. I can cut into the wall if I have to but obviously I'd prefer to have some idea of where the damaged wire is first. Does any of my rambling description help to pinpoint the area I should be focusing on.. or is there a better tool to help find it?
The other night my dehumidifier turned on and suddenly everything in 2/3rds of the house began cycling on/off and the lights that were on started strobing as well (led bulbs btw). I unplugged everything and reset the breakers, even though none were tripped. At this point, I was able to turn the lights on but they were dim and got dimmer with each new one switched on. The outlets would only power a night light.
After a lot of searching, I came to realize I had a MWBC. Nothing in the panel was labeled when I bought the house, so I figured all the circuits out. When it was all said and done, I had two 15's (one black wire to one leg, one red to the other), and two 20's (same config.). Everything else could be accounted for. The two 20's do nothing with the cb switched on or off but they do all have 120 coming from the breaker. One of the 15's will turn the utility and kitchen lights on and the other powers the bath, hall, beds, and porch lights. Also, noteworthy is the fact that the utility and kitchen lights are perfectly fine and they supply some voltage to the other lights as well, when both breakers are switched on.
The multimeter shows about .4 volts hot and .2 volts neutral starting from the first outlet and moving around the house until I get to the 3rd bedroom (these are the last 2 outlets) ..I say that because the last one only has one hot and one neutral. These 2 have about .8 volts hot and .4 at neutral.
I should add that there are some weird things that affect the lights being able to turn on. If I plug a night light into the first 3 outlets, I can switch all the beds and hall on.. but when I turn the bath light on, the other rooms go dark. If I don't use a nightlight in the outlet and instead turn on the back porch light.. the beds, hall, and bath can all be turned on at the same time. And if I turn on the carport light, it even gets a little brighter, but not so bright that it would blow the bulbs. Btw, the back porch light is controlled by the 15a that controls the beds and bath but it's in the same box as the kitchen lightswitch.. and both those switches show 1.4 volts.
I read that it could be an open neutral but I've been in every switch, outlet, and ceiling light and there's nothing that looks or smells burnt or broken. I also checked the neutrals at the panel. The other strange thing is that the outlet where the dehumidifier was plugged in doesn't let me switch the lights on when I plug a night light into it.. all the subsequent outlets don't as well. That made me think that was the most likely outlet where the damage would be.
I used a wire tracer from that outlet to the next and it doesn't seem like there's a break. Plus there's a little voltage going to all the outlets.. none are dead. But that voltage is definitely coming from the 15's and not the 20's, as it should be. I can cut into the wall if I have to but obviously I'd prefer to have some idea of where the damaged wire is first. Does any of my rambling description help to pinpoint the area I should be focusing on.. or is there a better tool to help find it?
