Shocked while installing dryer

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  #1  
Old 05-28-10, 04:13 PM
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Shocked while installing dryer

Hi there, another wiring-related question. I was installing my new washer/dryer, and hadn't got the washer lines screwed in completely, so ended up spraying water all along the back of the two appliances (I have them stacked). I shut off the water and was trying to tighten the hose line, and had my head against the dryer (which is on top) when I got a nice shock to the side of my head and my hand.
I have the old 3-prong style plug on the dryer, so I believe this means that the dryer is grounded differently than a 4-prong would be?
So, near as I can figure, I provided a path to ground through my head to my hand to the washer.
My question is: should I get it rewired for 4-prong to prevent this from ever happening again? I would prefer not to be shocked again by this, but really I don't want my wife or daughter getting shocked.
I will probably get an electrician to have a look at rewiring the run, I am just trying to pinpoint the problem, as I have some electrical knowledge, but am by no means knowledgeable. There wasn't a huge amount of water, which is what is also concerning me. Could the dryer cord be shorting to the case, or would this likely be the water that caused this?
 
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Old 05-28-10, 04:26 PM
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Pure water is actually a pretty good insulator not conductor but because of water containing easily ionized impurities has a gotten a bad rep as a good conductor. I would wonder if clean water alone was the culprit. I think your idea of switching to four wires is a good safety move and the electrician can determine if there is any other problem.

Do you have an electric water heater? A bad element and water with high mineral content could also be a source of the shock. Unlikely but it does happen.
 
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Old 05-28-10, 04:37 PM
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Is the washing machine circuit properly grounded. IF there were a short in the washer and that circuit was not properly grounded, your head could have completed the path to ground to the dryer. Your electrician should check both the washer and dryer for problems in addition to both circuits.
 
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Old 05-28-10, 07:59 PM
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You should have not gotten a shock if it is wired correctly. Check the machines and make sure they are correct.
 
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Old 05-29-10, 12:11 AM
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There one thing about the old 3 wire cord set up with dryers make sure you have the bonding strap or green wire hooked up with netrual conductors. {senice you mention the Electrician to come out and check it out for you that is the wisest move }

At the same time the Electrician can able check the bonding on the water pipes as well if you have copper water pipes { I am pretty sure they will check this anyway which I done very often always check the bonding espcally with older homes have issue. }

Merci,Marc
 
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Old 05-29-10, 11:04 AM
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Originally Posted by CasualJoe View Post
Is the washing machine circuit properly grounded. IF there were a short in the washer and that circuit was not properly grounded, your head could have completed the path to ground to the dryer. Your electrician should check both the washer and dryer for problems in addition to both circuits.
I was thinking that also. I have never been shocked by 240V, but I would've thought it would hurt worse than it did, which made me think it might be the 120V from the washer.

Back to the dryer explanation: I talked with an electrician at Home Depot who explained that if the neutral wire in the house wiring was defective, then that could have caused the shock.
Maybe someone who understands voltage a little better can check my understanding:
He says that the 3-prong uses the neutral wire as the "return" wire to complete the circuit (with the two hot wires being the "supply" wires) as well as being hooked to the ground (dryer casing). So, if there was a break in the neutral wire, then instead of returning to my circuit breaker box, the electricity would want to go to ground (through the casing of the dryer and whatever was in contact with the casing) Sound feasible? (excepting my return/supply analog's inconsistency with hole theory).
 
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Old 05-29-10, 07:21 PM
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A bad neutral connection to the house is a possibility, but that could also be causing you problems with all of your lights and receptacles in the house too. Are you having any problems anywhere else?
 
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Old 05-30-10, 09:05 AM
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Originally Posted by idyllhands View Post
(excepting my return/supply analogy's inconsistency with hole theory).
Fixed spelling

If the problem was just in the wire to the dryer receptacle, maybe I wouldn't see it elsewhere though?
 
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Old 05-30-10, 01:49 PM
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Why not take a voltmeter set to ac volts and test from washer chasis (unpainted metal or screw heads) to a good ground source - and also test from dryer chasis to ground source and see what the meter says.

I tested a fridge in such a mannor, that tingled me once, and got 120 volts to show on my meter when I went from fridge chasis to metal sink 3 feet away!
 
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Old 05-30-10, 03:04 PM
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Originally Posted by idyllhands View Post
Fixed spelling

If the problem was just in the wire to the dryer receptacle, maybe I wouldn't see it elsewhere though?
Good point. One of the hot legs to the dryer uses the neutral to power the 120 volt timer and motor. If this should be the case, the dryer won't run because you have no return path for the 120 volts to the timer and motor. Does the dryer run?
 
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Old 06-01-10, 09:37 AM
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Originally Posted by CasualJoe View Post
Good point. One of the hot legs to the dryer uses the neutral to power the 120 volt timer and motor. If this should be the case, the dryer won't run because you have no return path for the 120 volts to the timer and motor. Does the dryer run?
The dryer does run. I have not run it through a full cycle since I have not hooked up the vent yet, but it did start.

So, I think there are three possible options for what the problem is:
1) Ground inside dryer to chassis
2) Ground inside washer to chassis
3) Break in neutral wire between circuit breaker and dryer.

Would you agree, or could it be something else too?
 
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Old 06-01-10, 10:26 AM
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Break in neutral wire between circuit breaker and dryer.
The motor in the dryer and the circuit boards won't work with out a neutral unless it is one of those rare pure 240v dryers. If the name plate says 120/240v chances are it needs a neutral to work.
 
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Old 06-01-10, 11:12 AM
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Originally Posted by ray2047 View Post
Pure water is actually a pretty good insulator not conductor but because of water containing easily ionized impurities has a gotten a bad rep as a good conductor.
Even 100% water will conduct due to +H and -OH ions. If you sprayed deionized water on the appliance, that's a different matter.
 
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Old 06-01-10, 04:35 PM
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Originally Posted by telecom guy View Post
Even 100% water will conduct due to +H and -OH ions. If you sprayed deionized water on the appliance, that's a different matter.
What is interesting though, about that, is that even if an ohm meter is set to the 2 million ohms setting, no reading will occur, even when hot water and soap is added to the water, and stirred up....and the probes only 1/16th inch apart from each other, to boot.
 
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Old 06-01-10, 05:22 PM
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Originally Posted by ecman51` View Post
What is interesting though, about that, is that even if an ohm meter is set to the 2 million ohms setting, no reading will occur, even when hot water and soap is added to the water, and stirred up....and the probes only 1/16th inch apart from each other, to boot.
My high school physics teacher used a regular 120v lamp holder, bulb, beaker of distilled water and wire of the lamp cord split to two probes. The probes went into the beaker and the lamp was turned on. Not even a faint glow then salt (NaCl) was slowly added. As it was added the bulb got brighter and brighter.
 
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Old 06-01-10, 06:57 PM
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Originally Posted by idyllhands View Post
The dryer does run. I have not run it through a full cycle since I have not hooked up the vent yet, but it did start.

So, I think there are three possible options for what the problem is:
1) Ground inside dryer to chassis
2) Ground inside washer to chassis
3) Break in neutral wire between circuit breaker and dryer.

Would you agree, or could it be something else too?
As I recall, this is a 3 wire circuit, two hots and one neutral. If the dryer runs you can rule out your #3 option. I think you need to seriously look at options 1 and 2.
 
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Old 06-01-10, 07:06 PM
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according to wikipedia:

Sea water is about 10 million times worse conductive than copper. Drinking water is about 1000 x worse yet, DI water is another 1000x less conductive. What conductivity there is, is due to ionic transport. All numbers can vary by at least an order of magnitude. I've done the ohmeter probes in the water test and I get various readings, but usually below 1Mohm. I have softened water, likely the reason I get readings.
 
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Old 06-02-10, 02:23 AM
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Is there a way to verify the integrity of the house wiring before going to Sears? Would it be worth having an electrician investigate, or should I go straight to the store where I bought it?
What kind of tests would an electrician do?
And I do not have a DI water system, so no discussion on that is relevant to this thread
 
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Old 06-02-10, 06:48 AM
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Originally Posted by telecom guy View Post
Sea water is about 10 million times worse conductive than copper. Drinking water is about 1000 x worse yet, DI water is another 1000x less conductive. What conductivity there is, is due to ionic transport. All numbers can vary by at least an order of magnitude. I've done the ohmeter probes in the water test and I get various readings, but usually below 1Mohm. I have softened water, likely the reason I get readings.
So then.....what is the verdict then on the conductivity of plain old tap water? We have the ions transfer rationale and we have the ohm readings that do not show up......unless per yourself and Ray, when say salt is added.
 
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Old 06-02-10, 08:48 AM
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Originally Posted by idyllhands View Post
Is there a way to verify the integrity of the house wiring before going to Sears? Would it be worth having an electrician investigate, or should I go straight to the store where I bought it?
What kind of tests would an electrician do?
And I do not have a DI water system, so no discussion on that is relevant to this thread
Sorry about the digression. I would take an incandescent test lamp, with about a 100watt, conventional bulb. Unplug the dryer. Try the test lamp in the washer receptable first, just to get a feel for the normal brightness. Then, move to ONE hot and the neutral of the dryer recept. Try the first hot leg to neutral, then the other hot leg to neutral. DO NOT go from hot to hot, that will blow the bulb and fast. If the two hots to neutral give full brightness, I'd dry the dryer off, plug it in and try it out. If it works, I'd take an AC voltmeter and verify a low AC voltage reading from Dryer frame to a nearby water pipe. Expect a reading from 1 to 5 volts AC, NOT MORE. Wear rubber soled shoes and take appropriate anti-shock precautions. Consider the dryer frame dangerous when plugged in, until you verify with the voltmeter and a RUNNING dryer that the frame voltage is safe.
Yes, a defective neutral is the reason for the 4 wire dryer/oven outlets in new installs. There is no other point in the home where an open wire will cause a severe shock.
 
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Old 06-02-10, 07:22 PM
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Originally Posted by idyllhands View Post
Is there a way to verify the integrity of the house wiring before going to Sears? Would it be worth having an electrician investigate, or should I go straight to the store where I bought it?
What kind of tests would an electrician do?
And I do not have a DI water system, so no discussion on that is relevant to this thread
I think you need more than just an electrican, you need an electrician who is an excellent diagnostician as well. I think if I were you I'd check with some of the major supply houses in your area (after the morning rush, 9 a.m. would be a good time) and ask them who is excellent at diagnosing problems. I'm pretty sure you'll get several names and phone numbers. Once you have your man, explain exactly what happened to you and ask them to check both circuits and each appliance as well. Unless I miss my guess, you'll get an answer quickly.
 
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Old 11-05-10, 06:26 PM
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Just wanted to update this thread with a resolution: Sears sent a guy out (for free...I never realized how awesome Sears is.) and he stuck a Voltmeter on the leads and apparently whoever wired it up stuck a hot wire on the neutral land in the recepticle...Swapped the wires and now it runs like a charm, and no more shocks!
 
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Old 11-05-10, 07:15 PM
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Thank you for letting us know.
 
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