Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

Recently (or, perhaps, I recently noticed) my garage fridge started shocking me if I touch it in the wrong place. (A sampling of "wrong" places: the door hinge, a spot on the other corner where the paint is worn off)

The shock is quite severe, definitely not a static discharge.

I bought an outlet tester, which tells me that the outlet that the refrigerator is plugged into has an open ground. Is this enough to make the fridge shock me? I have checked for frayed or damaged wires inside the fridge and didn't find anything.

EDIT: More info: The fridge is currently plugged in to a surge protector, which is plugged in to a plug-in type GFCI, which is plugged into the ungrounded outlet.

EDIT 2: I have since fixed this problem by grounding the outlet in question. I don't know whether this masks a legitimate problem with the refrigerator, or if this was the actual solution, but the bottom line is that it not longer shocks me when I touch it. Thank you everyone for all of your help!

share|improve this question
3  
Use a multimeter to do a continuity test between the ungrounded (hot) conductor and the equipment ground conductor, this will confirm a ground fault. Unplug the fridge, set the multimeter to test continuity, touch one probe to the "hot" blade on the plug, and the other to the ground pin. If you hear a beep or get a reading, you have a fault. Repeat the test for the "neutral" and ground, in a modern fridge with a 3 wire cord neutral and ground should not be bonded in the fridge. Have the fridge serviced to repair the fault, before plugging the fridge back in. –  Tester101 Jul 21 '12 at 13:46
1  
Keep in mind, if the equipment ground was not faulty you may not get shocked, but there is still a fault in the fridge that must be fixed. –  Tester101 Jul 21 '12 at 13:48
    
@Tester101 this and your comment below are well worth being posted as an answer. –  BMitch Jul 22 '12 at 0:56
    
@Tester101 Agree with BMitch. Thank you for providing some actual diagnostics that I can perform. –  Dustin Rasener Jul 22 '12 at 12:44
    
@Tester101 I performed this test. Neither Neutral-Ground nor Hot-Ground were bonded. Hot-Neutral was. (as you would expect, right?) –  Dustin Rasener Jul 22 '12 at 13:28
show 16 more comments

4 Answers 4

An open ground is not in and of itself a problem. Grounds are there to dump excess voltage in case something goes wrong. If all our appliances worked properly all the time, there'd be no need for ground.

So what you have is two problems:

  1. Your fridge has a bare wire rubbing against the frame or other electrical short,
  2. And, the safety device meant to mitigate such a fault (ground) is broken.

If I were you, I'd replace the outlet, preferably with a GFI, and make sure the ground is attached. Then I'd have someone in to look at the fridge.

share|improve this answer
    
I have inspected the fridge in all the places I have easy access to (which includes a panel inside the unit itself), and all of the wires and insulation look pristine. Is there a failure besides "bare wire touching frame" that could cause the frame to become electrified? –  Dustin Rasener Jul 20 '12 at 20:16
1  
The leak to ground can occur anywhere a power conductor is in close proximity to a grounding conductor. Could simply be too much solder on a printed circuit board, or insulation failure inside an electric motor, or anywhere else there is insulation isolating power from a supporting bracket or such, where the insulation has broken down. Can be very hard to isolate. You do need to fix the outlet as well, but if you install a GFI with the current fridge configuration, the GFI will always trip and the fridge will never run. If you fix the outlet grounding, the shock you experience will be reduced. –  bcworkz Jul 20 '12 at 20:49
2  
Reducing the shock is not enough. It needs to be eliminated. Per Cudmore, you need to have someone fix the fridge! –  bib Jul 20 '12 at 23:05
1  
I was once told by an appliance repairman that modern refrigerators have small, low-voltage heaters inside the outside shell that warm the outside in order to prevent condensation. These heaters frequently short circuit. When it happened to me, the fridge didn't shock me, but it tripped the GFCI. –  Vebjorn Ljosa Jul 21 '12 at 9:00
    
@ bib. Thx for clarifying. I ran out of chars to say what I should have said. I handled that poorly. –  bcworkz Jul 22 '12 at 0:29
add comment

I'm not a certified electrician, but I have rich experience dealing with appliances that had similar issues, even two brand new washing machines of a well know European brand would do so. Every time it was solved by grounding the device - if there was wiring with ground wire then it would be connected to that wire and if there was not a ground wire it would be connected to improvised grounding that was likely not up to any code, but anyway each time the problem was just solved.

share|improve this answer
3  
+1, other comments have mentioned that the outlet grounding screw is not wired, and this appliance is designed to be plugged into to a grounded outlet. My guess is that the compressor motor is throwing off a good bit of static electricity, not unlike a Van de Graaff generator. –  BMitch Jul 23 '12 at 12:07
    
This is my current theory. The problem was solved by grounding the device. –  Dustin Rasener Sep 13 '12 at 20:32
add comment

How old is the refrigerator?

If the ref. is really old you might think about replacing it with a more energy efficient one or just get rid of it if it's not used much. Some utilities have rebates for old working refrigerators. An old ref. can cost a lot to operate.

share|improve this answer
    
It's 2004. I actually just bought it used. Also, technically it's an upright freezer. I've turned the coarse-adjustment screw on the thermostat to operate it at fridge temps. Can you guess what I'm using it for? This is my kegerator, and it gets used plenty. :) –  Dustin Rasener Jul 21 '12 at 12:58
    
By the way, it's funny you should mention the rebate. When we discovered that my previous kegerator was shocking me (yes, there is more to the story -- do you suppose it's relevant?), we replaced it, thinking that something had gone wrong. Our electric company gave us $30 to haul it off. –  Dustin Rasener Jul 21 '12 at 12:59
3  
@DustinRasener if this is the second fridge that has shocked you, open up the receptacle box and make sure the neutral and ground are not bonded in the box. –  Tester101 Jul 21 '12 at 13:50
    
I'm with @tester101. It sounds like there's stray voltage on the ground. –  Chris Cudmore Jul 21 '12 at 15:09
    
@Tester101: Thanks. I did just that, and the ground receptacle is not wired at all. –  Dustin Rasener Jul 22 '12 at 14:00
add comment

You say the fridge is plugged into a power strip and the power strip is then plugged in through a portable GFCI receptacle. If you are getting shocked by the fridge, but the GFCI is not tripping, then the GFCI is faulty and not providing you with any protection.

A plug-in GFCI receptacle tester has a button to trip the GFCI. I hope the tester you got is this kind; if so, you can use this to confirm your GFCI is busted, but I would just replace it rather than go without protection.

Now, on to the fridge. The tool you want to use here is a multimeter.

(Aside: If you're doing anything with electricity, you should have a multimeter. In a pinch, you can get by with a so-called "neon circuit tester": this has two leads and a light on the body. The light lights up when it detects a high enough voltage traveling across the leads. Be careful; many of these are intended for automobile use and will not survive mains power. I've used a couple, and I like the Gardner Bender GET-213HV, because the leads clip to the body at the right width for a US receptacle and the light is good and bright.)

Plug a 3-prong extension cord into a grounded outlet. Run the cord over by the fridge. Take your multimeter/neon tester and stick the black COM lead into the grounded U-slot on the extension cord. Touch the other lead to one of the places you felt a shock on the fridge. If it reads a voltage difference, congratulations: Your fridge is live and ready to shock the daylights out of you. Unplug the fridge and move your chilled goods elsewhere.

I don't know whether an electrified fridge could be salvaged, or whether you'll have to get a new one. Good luck.

P.S. Those receptacle testers are apparently considered somewhat unreliable. You can follow up by testing everything they test using your multimeter/neon circuit tester. Reversed polarity: one probe in the long slot, one in the ground slot, if you have power, oops. Ground: one probe in the hot slot, one in the ground slot, no power, no ground. (No ground, and you can't really test for reversed polarity, either; use the extension cord trick to get a known good ground.)

There's also always the open up the outlet, pull everything out, and see how it's wired together trick. It takes far more time, but it lets you see directly whether there's a ground screw, whether anything's attached to the ground screw, whether the polarity's reversed, etc. But don't open things up unless you're comfortable putting them back together.

share|improve this answer
    
A GFCI doesn't detect current on the ground, it detects a difference in current between the ground and neutral. You can get shocked via a static charge or an improper ground and have a perfectly functioning GFCI. –  BMitch Jul 23 '12 at 11:57
1  
@BMitch GFCI detects a difference in current between hot and neutral, not ground and neutral (current in = current out). –  Tester101 Jul 23 '12 at 12:14
    
@Tester101, doh, before my morning caffeine, that's what I meant to say. Thanks for the correction. –  BMitch Jul 23 '12 at 12:42
    
@BMitch Doesn't getting shocked via an improper ground mean current is flowing from hot and returning via you, not via neutral? I'd expect the difference in current out via hot and that returning via neutral should be enough to trigger the GFCI if OP is getting shocked. –  Jeremy W. Sherman Jul 23 '12 at 14:45
    
@BMitch Ah, just saw your guess about static electricity. If that's so, then yes, the GFCI is not at fault. But testing with a multimeter should reveal that: you'd see voltage on contact that dissipates right afterwards, rather than the steady voltage you'd see with a ground fault. –  Jeremy W. Sherman Jul 23 '12 at 14:47
show 5 more comments

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.