220V Outlet Voltage

Question

220V Outlet Voltage

rharr (Mechanical)

(OP)

21 Feb 08 10:55

Let's start by letting you know I'm a mechanical engineer with an electrical question.

My stove recently died. One of the elements in the oven arced. However, nothing on the stove works now.

After checking the fuse panel and not finding a tripped breaker or blown fuse (I also have part of my house on an old style screw in fuse panel) I unplugged the stove and checked the outlet for power. It's a three prong outlet. (Using #1 as the vertical slot at the 6 o'clock position, #2 is at 10 o'clock, and #3 is at 2 0'clock) From #1 to #2 I get 120V. From #1 to #3 I get 40V. From #2 to #3 I get 80V. If I have a blown a fuse on one leg, wouldn't I see 0V on that leg? What could the problem be? Do I have a short somewhere?

IRstuff (Aerospace) · Answer 1 · 2008-02-21 12:21:00

Depends on whether there's anything else on the circuit. If you have another appliance plugged into the same circuit, there there might be some propagation of voltage through the other appliance into the otherwise open circuit.

TTFN

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rharr (Mechanical) · Answer 2 · 2008-02-21 13:24:43

There shouldn't be anything else on the circuit. Aren't stoves supposed to be wired separately back to the breaker/fuse panel? Also, I traced the wires and, with the exception of an additional panel/switch midway, there doesn't seem to be anything else. I have no idea why the additional panel/switch is there. This wiring was done many many years ago and the building has been used for a number of businesses, including a body shop, in its 100+ year history. It could be that this 220 line had other uses during the building's previous life and was dedicated to the stove when the residence portion was built on.

I just checked the fuse box and the same voltages apply to the terminals there. 120 to neutral from one leg, 40 from the other, and 80 between them.

IRstuff (Aerospace) · Answer 3 · 2008-02-21 16:08:34

As a check, you should repeat the test at the breaker with the breaker opened to determine whether it's inside your stuff or coming directly from the utility. There may be an partial or intermittent open in the feed from the utility.

Older buildings are grandfathered as far as code and modern practice are concerned. Usually, unless the appliances were changed out for ones with bigger current draw, the wiring is left unchanged, unless the new appliances start popping the fuses on a routine basis.

My parents' house, built in 1926, is definitely NOT wired adequately for servicing modern appliances.

TTFN

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rharr (Mechanical) · Answer 4 · 2008-02-22 09:56:03

You could have been right about another appliance effecting the voltage. I traced the dryer line and found that it feeds into another side of a junction box in the line from the stove back to the fuse box. The way the box is setting, the dryer line is hidden.

And about an intermittent open. We found a bad fuse on the main block as well as damage to the area around one of the connections for this fuse block. Looks like I need to finally replace the old fuse box.

Thanks for your help.

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220V Outlet Voltage