The house came with a washing machine already hooked up. Now, this is a strange house. It was originally built in 1934, and it’s had additions. One of those is a travel trailer. The trailer has a structure built around it on three sides (the side that’s right on the property line is exposed), a roof, and a passageway between it and the house (which also has an alternate entry door). It was a year before I went into it. Turns out there’s a washer and a dryer sitting in there. Since I’m ‘cleaning house’ – moving storage stuff from the biggest bedroom into the trailer temporarily (until I get a garage built) – I thought it would be nice to have a dryer. For the past two years I’ve been doing the wash here and driving to the laundromat a mile away to dry it.
The problem is that the dryer had a 4-prong plug on it. I called an electrician to come over and replace the three-prong 220v outlet with a modern 4-prong outlet, and to bring it up to modern code. I also wanted to have my fuse box replaced with a circuit breaker box. Turns out that the way this place was put together so many decades ago, this would be a major job of work. He said it would be better if I wait until the garage is being built before I upgrade the electrical system. For the time being, I may as well just put a 3-prong plug on the dryer. I asked him to test the outlet, just to make sure it was powered.
Uh-oh. 298 volts. Way too high. He called the power company to come out to check their transformer. They tested the lines coming into the house, and they are 220v. Somehow I’m getting extra voltage. This could ‘burn out’ electrical items. On the other hand, my friend used the higher voltage (140v from the 110v outlets) for the two years he owned the place, and I’ve done as well. Zero problems with the lights, the stove, the computer, the TV, the various electronics, the fridge… Everything works fine.
So I’m taking a chance. I bought a new lead with a 3-prong plug at the hardware store and I’ve installed it on the dryer. I plugged it in, and the dryer works. Now I’m doing a bit of washing. I’ll try the dryer when it’s done. I have a fire extinguisher standing by.
What do you get if you cross a rotorcraft with a rhinoceros? ‘Helifino’!
I don’t really know. The power guy said something about grounding, but I still don’t get how I could have more voltage in the outlet than is going into the box.
Open neutral-ground bond at the breaker box. The lines from the transformer to your your house are normally comprised of two hot lines with 240 VAC between them, and a neutral center tap, which is supposed to be grounded to hold it at zero volts. The 120 V outlets use one hot line and the neutral, while 220 V outlets use both hot lines, and appliances which use it may or may not make use of the neutral. If this bonding becomes corroded, dirty or loose, the neutral can float up to any value from zero to the line voltage of the transformer primary, which is typically 7,200 volts for a residential installation. The line-to-line voltage will remain at 240 V, but the line-ground voltage will read high. Since your reading is only about 58 volts high, give or take, your ground-neutral bonding is probably just a little corroded or dirty and needs cleaning and/or tightening.
That sounds like what they guy was saying. I didn’t catch that both lines are 220v. The problem is that, as I said, the house is very old. The meter box doesn’t have a ground. The ground apparently goes somewhere else. I was going to get a modern ‘square’ meter box so that I could do the circuit breaker conversion and replace the 200v outlet, but the electrician says the original box is in a poor place. I’d be better off (i.e., it’s cheaper) to wait until I do the garage.
As long as none of the cicuitry in the dryer is ground-referenced, you’ll be probably fine, if a tad unsafe. The chassis of the dryer will be 58 V above ground, which is high enough to give you a bit of a nasty buzz, if you happen to touch it when you’re well grounded. That rarely happens. Even 120 V shocks are not often fatal, since it takes a fairly unusual circumstance to be in contanct with a low-impedance ground, but I wouldn’t go looking for excuses to experience them! I’d be more careful than usual when using it, if you must.
Its like a feed back loop. Hubby and I has some experience with this sort. We re-wired our 1942 built house ourselves.
The wiring for the dryer, or any 220 appliance is 10-3 instead of 12-2, like the rest of the house. 12-2 has three wires, and 10-3 has 4. Your antique fuse box doesn’t accommodate a proper ground, so the neutral is hot when it isn’t supposed to be.
If you have a three way switch anywhere in the house, it could be part of the problem, it too uses a wiring pattern that the fuses aren’t designed to handle.
Make sure your fuses are the correct size, and remove each of them and make sure no one has disabled them with a bit of metal or a penny.
Be very careful while checking, the inside is hot.
Remember, don’t use your electric range while the dryer is going. Don’t put bigger fuses in when they blow when you overload the system. Buy more fuses.
Fuses were fine when houses had a 40 watt light bulb in each room, and one outlet to plug in a radio or phonograph. Most houses now need 200-400 amp panels to light up our lives.
Just be careful, 'k?
Huh? Fuses aren’t any different fundamentally, than circuit breakers are today–the interrupt current through a hot line when the current exceeds a given value. Current-handling capacity isn’t really an issue, either. Circuit breakers replaced fuses mainly due to convenience, not so much safety. I’ve personally seen fuses rated at 200 amps, and I have no doubt that higher values are available. The problem is as I outlined above. Good grounding practice wasn’t common in ye olde days, so problems like this arise frequently in older construction.
Yes, you’re right, and if I didn’t make myself clear I apologize. I thought I was pointing out that fuse boxes don’t accommodate a grounding wire, and that the system isn’t designed for multiple modern appliances. And finally, that fuses are fairly easy to by-pass, setting up a very dangerous situation.
If the house was wired in 1934 and has not been updated, it probably has a 40 amp service.
I know I don’t always make myself clear, but maybe you could cut me a little slack for a while, huh?
