I went on a service call where the neutral was lost going to a house which sent 240 volt through the 120 volt branch circuit wiring. Well the homeower is out 2 TV's, a VCR, a stereo, and a microwave.They all seem to be damaged by the 240 volt surge.
Does anybody know how much damage may have been caused to the TV's and other appliances from the 240 volt surge?I'm thinking that maybe just a power supply transformer fried.
I wanted to tell the customer if the appliances were worth getting repaired.
It will depend very much on the design of the equipment. Some TV power supplies have an overvoltage "crowbar" circuit to protect the rest of the circuitry, in which case some work on the power supply components should restore operation, but it's not universal.
You could expect to find damaged filter capacitors and quite possibly burned out transistors and integrated circuits in bothe the TV and the audio equipment. If the microwave oven is a modern type with digital control, then the main board may well be shot due to the overvoltage.
Unfortunately it's impossible to be any more precise without actually testing the equipment to see what's been fried.
Re: 240 volt blasts appliances#43978 10/26/0407:48 AM10/26/0407:48 AM
Electure is right about the voltage. What you normally get is more like 145 on one leg and 95 on the other. Together they will both always add up to 240. The more load put on 1 leg(voltage drops), the other leg goes up the same amount the other drops.
It's actually quite interesting to witness how the lights get brighter when a load is appied to a circuit on the opposite leg.
Re: 240 volt blasts appliances#43980 10/26/0411:13 PM10/26/0411:13 PM