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I purchased a small freezer and the instructions state to plug it into a three prong outlet. In my garage there is a 2 prong outlet that I use with an adaptor. Is it safe for me to plug the freezer into the 2 prong outlet with an adaptor?

Is it safe if I plugged it into one of those outlet strips? I would be plugging the strip into the two prong outlet with an adaptor.

Thank you in advance! E

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One way to do this, that is National Electrical Code compliant. Would be to replace the two prong receptacle, with a GFCI receptacle. While this does not provide an effective fault current path, it should prevent electrocution in the event of a fault.

Technically to be code compliant, you'll have to stick a "No Equipment Ground" sticker on the GFCI receptacle. There should be one in the box that the GFCI receptacle comes in.

Those three prong adapters that connect to the faceplate screw, do not provide an effective fault current path. And therefore would not allow a fault to be cleared by the breaker.

The "correct" way to do this, would be to install a code compliant grounding conductor and three prong receptacle. Though since the receptacle is in a garage, GFCI protection is required anyway.

NOTES:

  • Even though most modern devices should work with GFCI devices, some manufacturers still produce equipment that may trip the GFCI.
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Either way you are using your appliance without the grounding conductor required (for safety reasons) by the manufacturer.

Will it work? Yes

Is it safe? Homes were not wired with grounding conductors for many decades

Should you look into alternative grounding methods for your appliance? Yes

The "adapter" you reference is likely equipped with a grounding terminal to facilitate an auxiliary, or supplemental, grounding conductor. You should see if you can run a wire from the terminal to a grounding rod or other suitable appurtenance such as a metal cold water pipe that has an uninterrupted path to the earth.

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Some people attach the adapter to the cover plate with the plate screw, assuming this "grounds" the adapter. This is only the case if the receptacle is bonded to a metal box which is grounded, and that is rarely true in a home with 2-prong receptacles.

enter image description here

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    Running the grounding conductor to earth, does not provide an effective fault current path. Without the fault current path, the breaker will not clear the fault. The grounding conductor must provide a low impedance path back to the source, not the earth. – Tester101 Mar 12 '16 at 4:06
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    @Iggy It doesn't care where ground is, it cares about resistance. If your path to ground is high resistance, it can easily have a fault and NOT draw enough current to trip a breaker. – Grant Mar 12 '16 at 4:36
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    @Iggy I was commenting on this statement "that has an uninterrupted path to the earth.". You don't need a path to earth, you need a path to the source. – Tester101 Mar 12 '16 at 4:49
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    @Iggy I think you misunderstand how circuit breakers work, how the grounding system works, and how ground-faults work. – Tester101 Mar 12 '16 at 5:07
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    @Iggy, the earth has NOTHING to do with breakers tripping and clearing faults. The term "ground" is erroneous when it comes to equipment grounding. We call it ground, but it has NOTHING to do with the dirt ground outside. All "grounds" are NOT "direct paths to the earth". Equipment grounds are direct paths back to THE SOURCE, as Tester101 correctly pointed out. – Speedy Petey Mar 12 '16 at 14:14

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