Originally Posted by
RANDY NICHOLAS
Nearly all 120 receptacles that I check register 113-118 with an ampmeter.
I inspected a house last year, built in 2004, and the buyer didn't occupy for six months, then let her daughter move in.
Her daughter called me to complain about the electrical receptacles (blown tv, stereo, and computer). She just bought her third clothes dryer in six months. The appliance store said "this is the last one we will replace".
She called the electrical provider and the city inspector. They told her the ground wire is too small.??
I checked the
inspection report, all in good order: 225 amp. service, #4 ground wire attached to the ground rod...
I went to the house checked the panel and ground wire/rod.
I then checked the breakers with an ampmeter.
120 amp read 140 amps
240 amp read 280 amps.
I checked the receptacles 140 amp reading. Dryer receptacle 280 amps.
I turned the oven on: Instant HOT!
I turned the cook top on: INSTANT VERY HOT!!!!
My conclusion was that the electrical transformer is not regulated and is overpowering the electrical to the house.
Randy,
First, a minor correction
... you means "volts", not "amps", right?
With the 120 volt circuits you could read all kinds of voltages if there is a neutral problem (not a "ground" problem, but a neutral problem). If you leave turned 'on' whatever is 'on' and check voltages, you should get two different voltages on each phase, but both should add up to 240 volts (give or take a few volts), i.e., if one phase leg reads 60 volts, the other will read 180 volts (60 + 180 = 240).
If, however, you turn 120 volt lights, appliances, etc. on and off, the voltage will change as you do so, with no apparent reasoning behind it.
HOWEVER ... all 240 volt circuits will still read 240 volts, they will be unaffected by a bad neutral/bad neutral connection.
In converting you "amps" readings to "volts", the thing which stands out to me is this one "240 amp read 280 amps.", as that would be 280 volts, or 277 volts ... which would indicated an improperly connected 3-phase transformer somewhere, maybe feeding her house.
If that's the case (and there is no bad neutral), then the 120 volt circuits will be half that 277 volts, or 138.5 volts - which is eerily close to what you read at "120 amp read 140 amps", i.e., 140 volts.
First, DO NOT put that you used your ammeter and read amps, you used your voltmeter and read volts.
Second, DO NOT put "My conclusion was that the electrical transformer is not regulated and is overpowering the electrical to the house." as transformers are not "regulated".
I would even hesitate to state for sure that it was the power company based on your readings as you stated them (although they do work out nicely to 277 volts).
In a case like that, and if the house is not far from yours or not far out of the way, go back tomorrow and measure the voltage at the service equipment, i.e., the main disconnect. *IF* you are indeed measuring 277 volts at the two phase conductors coming in from the service, there is indeed a power company problem and they need to be called ASAP.
But, for the life of me, I can't figure out how they would have mis-wired that transformer to get 277 volts instead of 240 volts, but that would be the logical place to look first. Maybe they have voltage problems feeding into that transformer?