When I run the microwave oven in my rented apartment, the incandescent lights nearby glow much brighter.
What sort of mis-wiring could cause this?
EDIT: Suspecting a bad neutral connection, I measured the voltage between hot and neutral at a nearby electrical outlet. The voltage was 113 VAC. When running the microwave, that same voltage goes up to 129 VAC.
The voltage at that outlet measured between hot and ground is the same as between hot and neutral (i.e. it also increases when the microwave is running).
On the same circuit as the microwave, the voltage is 126 VAC without the microwave and 108 with it running.
I assume this means that the neutral and/or ground connections to the house may be faulty?
Best Answer
The problem was a bad neutral connection from the transformer on a pole.
I called the power company--they had trucks out to replace the power line within 30 minutes.
Now the power variation is very small. Without the microwave running, I measure 117.5 volts on the lamp circuit and 118.2 volts on the microwave circuit. With the microwave running, the voltages go to 118.2 and 114.0 VAC.