09/20/2022
I have experienced this situation myself and it is very dangerous and somewhat mysterious to people with little electrical knowledge. I have much experience with electrical circuits but I had never seen this situation before. I had a service call for a furnace where the furnace electrical disconnect was glowing red. The customer experienced damage to several electrical appliances. I actually got shocked when I touched the electrical oven and the kitchen sink at the same time.
An Open Neutral in the Electrical Panel
When a break occurs in the main neutral between the panel and the line transformer, both hot wires are still energized. Electricity flowing in one hot leg can't find a return path through the neutral wire, so some flows to ground and some flows through the other hot leg.
The result is that all circuits in the house essentially become 240-volt circuits, and because the two hot legs are connected, the load on one leg affects the load on the other. Lights on the leg with the smaller load get more power, and they get brighter, while those on the leg with the larger load get dimmer.
This is a dangerous situation because devices can overheat and start a fire. There is also the possibility that a person could suffer an electrical shock from an appliance! You should call an electrician as soon as possible.
