My wife and I have been bouncing around getting an upright freezer for the garage to store bulk buy meats and things of that nature. It is an older house that mostly has two pronged plugs in the walls. The service panel was updated prior to my getting into the house to breakers from the old screw in fuses, and I have gone thru and upgraded some of the plugs to three prong, but most of the ones in the garage are still the old two prong. Is it safe to plug a three pronged plug from, lets say, an upright freezer, into a two prong outlet using a three to two prong adapter? My dad had a ton of them in use way back when, but I was never sure if it was ok to do or not. I am thinking, if needed, I can swap out the old two prong plugs for threes and run a ground either into the gang box or nail it onto the stud of the house. Thoughts? Rock On!!!!!!!!!!
For any electricians out there
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You can replace the two-prong outlet with a three-prong GFCI outlet. It takes 15 minutes and costs $15. No adapter needed and it's safer.
P.S. I'm not an electrician.
P.S. I'm not an electrician.
VikeMan
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I'm no electrician either. But I do know that a GFCI outlet (or any 3-prong outlet) needs to be grounded for the ground to work. OP's gang box apparently does not have a ground, so he can't simply replace the existing outlet with a GFCI outlet.
shoengine
Whale Noun Member
You'll notice that on those three to two prong adapters there is a lug. That is for a ground wire. We've all done it but you are supposed to actually ground that three prong adapter.
That said it is never "safe" to bypass the earth ground on anything with a conductive outer shell, like a fridge or freezer. Is the garage attached? Can you just run a copper ground wire back to the panel?
That said it is never "safe" to bypass the earth ground on anything with a conductive outer shell, like a fridge or freezer. Is the garage attached? Can you just run a copper ground wire back to the panel?
InspectorJon
Well-Known Member
I'll preface this by saying this pertains to 120 volt systems like in the USA, Canada and Mexico.
It is not permitted to install a three prong outlet in an ungrounded system unless it is a GFCI receptacle. The primary reason is that someone else is likely to come along later and assume the receptacle is grounded. It is permitted to install a GFCI receptacle in an ungrounded system. The GFCI protection operates by sensing an imbalance between the grounded and ungrounded conductors (neutral and hot). GFCI protection does not require a ground to work. The GFCI is effective in preventing someone from getting a shock or electrocuted. It does not replace a ground. The grounding conductor (ground wire) is there primarily to trip a circuit breaker if there is a direct short to a grounded component of the system.
VikeMan
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Yes, but this doesn't mean that an appliance that is supposed to be plugged into a grounded receptacle should be plugged into that ungrounded GFCI receptacle. I know you know that, but I'm not sure if the OP would.
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InspectorJon
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The building codes in the US stipulate that any product is to be installed according to the manufacturer's installation instructions. If a product's instructions state it should be plugged into a grounded outlet then plugging it into an ungrounded GFCI receptacle would be an incorrect installation.
Installing GFCI protection is all locations where it is currently required in new installations is a good safety upgrade and is highly recommended, even on old ungrounded systems. That would include garages, kitchen countertops, bathrooms, laundry rooms, exterior receptacles and crawl spaces. I think that is it but there may be others.
If the OP were to install a GFCI in his garage and plug the freezer into that, it would be safer than just plugging it into the ungrounded receptacle with an adapter. It would not be code complaint but might be a reasonable compromise financially. One thing I have learned is that people have widely varying tolerances for risk and imperfection. A perfect code compliant installation would require installing a new three wire conductor from the circuit breaker to the receptacle that the freezer is plugged into. A third grounding wire run separately from the cable supplying power to the receptacle would largely provide an effective ground but is no longer a permitted installation for reasons that eliminate some remote possibilities for system failure.
Installing GFCI protection is all locations where it is currently required in new installations is a good safety upgrade and is highly recommended, even on old ungrounded systems. That would include garages, kitchen countertops, bathrooms, laundry rooms, exterior receptacles and crawl spaces. I think that is it but there may be others.
If the OP were to install a GFCI in his garage and plug the freezer into that, it would be safer than just plugging it into the ungrounded receptacle with an adapter. It would not be code complaint but might be a reasonable compromise financially. One thing I have learned is that people have widely varying tolerances for risk and imperfection. A perfect code compliant installation would require installing a new three wire conductor from the circuit breaker to the receptacle that the freezer is plugged into. A third grounding wire run separately from the cable supplying power to the receptacle would largely provide an effective ground but is no longer a permitted installation for reasons that eliminate some remote possibilities for system failure.
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Shocking! ...A garage without proper grounded outlets? Are you sure it's not a bedroom that someone installed a garage-door on? I'm probably biased though; I only have a one-car detached garage which I'm unlikely to ever park my vehicle in again, as it would get in the way of using all my grounded tools that take up most of the space. 
Have you thought about just buying a roll of Romex and rewiring?
Have you thought about just buying a roll of Romex and rewiring?
How long ago did they replace those fuse boxes with breakers? Anything grade level (i.e., garages) requires 3-prong grounded outlets and GFCI, and that has been code for a couple decades.
If the service panel has a bay left in it for another breaker, you could add a 15 or 20 amp GFCI breaker and run a branch circuit with some 2 wire w/ground Romex to a few outlets to run your freezer, etc.
madscientist451
Well-Known Member
I'm guessing that your "plugs" you have replaced are the 3-prong receptacle? Did the receptacle box have the hot, neutral and the ground wire available? Did all those wires get properly attached to the receptacle? First, get a cheap receptacle tester at Home Depot or Lowe's (if you don't already have one) and see if your receptacles are wired correctly. If none of this makes any sense, go watch some you tube videos on the subject and/or pay an licensed electrician to come in and look things over for you.
I am not an electrician either. I have lived in houses with old panels with screw in fuses. The neutral was grounded at the panel with a ground bond in the panel. If your house has metal conduit and metal boxes then the conduit and boxes will be grounded. The three prong outlets connect the ground prong through the mounting screws to the box. While this does not meet current codes it will provide a ground that is separate from the neutral prong/wire.
shoengine
Whale Noun Member
@madscientist451 is on the spot. A receptacle tester will do the yeoman's work to determine if the plug is grounded correctly.
It'll work, but it's not safe at all. Exposed metal on appliances are connected to that missing ground.
If you have a ground wire:
- If a live (120V) wire becomes loose, touches the metal cabinet of the appliance, the breaker trips. Your wife lives.
If no ground wire:
- If a live (120V) wire becomes loose, touches the metal cabinet of the appliance, nobody notices. Your wife touches the appliance. She potentially becomes the path to ground, she dies.
I'm sure living in your area is expensive. Still, you should consider bringing your wiring up to modern standards.
Wow, first of all, thanks to all who replied. I am going to try and answer and expand on some of the posts. First off, I have no idea when the panel was updated. I have been in the house for about 25 years and it was done before I got there. So, with that said, some of the house has been switched to Romex style (the kitchen for sure, and probably parts of the living room). While, I believe the other parts of the house, are still on the old knob and tube. I only say that because the wiring when i changed the plugs still had the old black and white covering on them. I have a ground rod in the corner of the garage under the panel that has a thick wire attached to it, so I assumed that was the ground for the system. I have also seen in the attic a white wire that seems to run thru most of the house, and I thought that might be the system ground. I replaced some of the plugs in the rooms, but that was so long ago, I don't remember exactly what was there and what wasn't, but for some reason I think I ran a ground wire from the new plug onto the ground screw on the box I was replacing the plug in. I am not an electrician, so this is all very greek to me. I do know the 3 to 2 plug adapters have a ground tab on them, I was thinking that must go into the screw that the cover is screwed in on. I just put 20k into my roof, so money is a bit tight right now. If need be, I am ok with waiting. I think the plugs I have in the garage, at least the ones I can see, were 3 prong, but I have no idea if that means the garage has been updated. My initial thought was, replace the plug in the box and run a small ground wire from the ground screw on the plug to the ground screw on the box in the wall. I am guessing by what I am reading that isn't going to work. So, with what I have read, it is probably not a great idea to do anything right now and keep stuffing my freezer in the kitchen LOL.
I wish I could afford it. I just paid about 20k for a new roof and gutters. So, money unfortunately is a bit on the lean side right now.
I have a tester as well as a tool that, if you pass it by the plug it makes a beeping noise. No idea what that is called. LOL. I also have another tester with two leads that you put into the plug itself and it will light if the plug is hot. Do any of these sound like what you are talking about?
I am pretty sure the boxes were metal. I guess I can open one of the plugs in the rooms and see what is there.
Well, after reading all the posts, I am guessing my decision is going to be to hold off. I don't know that much about all this crap and you guys have me pretty scared to do anything. LOL. The plugs I replaced were done years ago, so I am pretty good there. But to mess with not grounding the appliance and having issues just isn't worth it. I probably should save some cash I guess and get an electrician to go thru the house, but that will be in the tens of thousands and I just don't have that kinda cash right now.
Thanks to all who replied. It made little sense to me, but was enough for me to scrap the whole idea.
Thanks to all who replied. It made little sense to me, but was enough for me to scrap the whole idea.
VikeMan
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You mentioned that your garage receptacles are 3-prong type, but don't know how to check them. There are a few choices of tools to check for grounding...
1) Neon Circuit Tester
2) Plug In Circuit Analyzer (aka 3-wire tester)
3) Multimeter
All are easy to use. Plug In Circuit Analyzers are pretty cheap (typically less than $10), and are particularly foolproof. You literally just plug it in and see which lights light up, and compare to the diagram printed on the plug.
Just how old is your house? Are the wires in your garage exposed? What do they look like? As beermanpete said, it is not always necessary to have a separate ground wire for something to be grounded. With older metal clad wiring the cladding IS the ground wire.
Test the receptacles with one of the tools that VikeMan suggested. They're either grounded or not. If not, getting an electrician to install a new grounded circuit for a freezer shouldn't set you back too much, assuming that your panel isn't already full.
Test the receptacles with one of the tools that VikeMan suggested. They're either grounded or not. If not, getting an electrician to install a new grounded circuit for a freezer shouldn't set you back too much, assuming that your panel isn't already full.
Cool. I was doing a bit of looking on Youtube and saw how to check them, so I might just for the heck of it see what I have and report back. I have two of the three, so I think I can figure it out. Or check the local Home Depot or Lowes and see if they have the plug in one. I'm guessing that if my plugs are only two prong, the plug in tool won't work though. Darn, oh well, I will go with what I have.You mentioned that your garage receptacles are 3-prong type, but don't know how to check them. There are a few choices of tools to check for grounding...
1) Neon Circuit Tester
2) Plug In Circuit Analyzer (aka 3-wire tester)
3) Multimeter
All are easy to use. Plug In Circuit Analyzers are pretty cheap (typically less than $10), and are particularly foolproof. You literally just plug it in and see which lights light up, and compare to the diagram printed on the plug.
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House is about 50 years old, but the panel is newer, but at least 25 years old. The wires in the garage are mostly in the wall, but there is a box near the door that is metal and has 4 plugs in it. I believe that was there when I moved in. I am 99% sure the wires in the wall are not what you have pictured. I have seen those and don't remember seeing anything like that in any of the walls I opened to do misc work. But, I am going to check the plugs in the house that I know I have not touched and see what happens. Probably see what I can find at the big box home improvement stores and see if I can find one of the plug in tools that was suggested.
OK, so I got home and it was going to bug me so I checked an easy to get to plug. It is a 3 prong plug, but I know all I did was change out the old 2 prong for the 3 prong. I did not add any wires that I can remember. I set my meter to VAC and used the 200 setting. I put the black tester into the left side with the longer slot, the red in the right side with the shorter slot. Measured 120, but it bounced around a bit. More than likely because I was not holding the probes super still (shaky hands, lol). Then I moved the black probe to the ground hole in the plug and left the red one where it was. Read again in the 115 to 120 range. I then moved the black back to the left elongated plug and put the red in the ground hole. No reading at all. As I understand it, that means that circuit is grounded. I checked both plugs on the box and they were both the same. So, with that being said, and knowing I have not done anything to the wiring other than change the plugs themselves, it would seem I am grounded. My big question now is, how to I check the only two prong plug in the house, which of course is the one she wants to use for the freezer? Or do I change it to a GFCI three prong and then check it like I did the others? Sorry for the stupid questions, but once I get a hold of something I don't let it go until I have an answer. Even if it is not what I want to hear. LOL. Anyway, I am off to bed, and will check a few of the other plugs in the house in the next few days, but just wanted to post what I found on a plug I am sure I did not touch the wiring, just the plug itself. Thanks to all who replied. Rock on!!!!!!!
I don't know anything at all about how residential construction was done 50 years ago on the west coast, but if we were talking about a house built east of the Mississippi in the 1970s I'd happily make a small wager that the wiring is the metal clad stuff I posted the picture of.
Might help if you post a picture of your panel.
I hesitate to post this since will probably start a big argument about what the NEC does and doesn't require in kitchens, basements, garages etc, but there is one major (and obvious) potential problem with plugging a freezer into a GFCI receptacle. If it trips while you're away for more than a few hours, you will return to find a defrosted freezer and a big mess with a lot of spoiled food.
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Given how you've described your electrical experience, I thought I'd look this up quickly and add my own recommendation to @VikeMan 's #2:
https://www.homedepot.com/p/Power-Gear-3-Wire-Receptacle-Tester-50542/206212329That one is probably the most useful for an amateur... I always kept one in my gear-bag when I had to use mains-power on locations..You'd be suprised at just how common it is to find outlets installed by supposed professionals who seem to think the hot and neutral wires are interchangable. If you decide to change out any outlets and simply add a ground wire, you'll want that to test it when you've finished.
Given what I've seen in your posts, you're a competant DIY'er, with good safety-sense... pick up a book;
https://duckduckgo.com/?t=ffab&q=residential+wiring+DIY+book&ia=webor find an online forum or some such and take a few days to read over. You'd probably be surpised at how simple residential wiring actually is.
https://www.homedepot.com/p/Power-Gear-3-Wire-Receptacle-Tester-50542/206212329That one is probably the most useful for an amateur... I always kept one in my gear-bag when I had to use mains-power on locations..You'd be suprised at just how common it is to find outlets installed by supposed professionals who seem to think the hot and neutral wires are interchangable. If you decide to change out any outlets and simply add a ground wire, you'll want that to test it when you've finished.
Given what I've seen in your posts, you're a competant DIY'er, with good safety-sense... pick up a book;
https://duckduckgo.com/?t=ffab&q=residential+wiring+DIY+book&ia=webor find an online forum or some such and take a few days to read over. You'd probably be surpised at how simple residential wiring actually is.
shoengine
Whale Noun Member
If you are in an attached structure, the neutral (wide blade) and ground should be bonded in the main panel. I haven't tried this myself, but you should get continuity on your meter between the neutral and ground.
Those three light testers are awesome, cheap and make it dead simple to check common wiring faults. In fact the several times I've done rough-in inspections on my house wiring the inspector always uses one of those to check outlets.
FYI, code these days require GFI in all potentially wet locations, including the kitchen, bathroom, garage, outdoors and detached structures. AFI are required in all common areas such as dining and living areas. GFI on branch circuits can either be provided by a dedicated GFI breaker (what I do) or GFCI outlet (cheaper). To extend protection to downstream outlets the outlet needs to be the first on the circuit. There is a limit to how many downstream outlets can be protected by I forgot how many.
Those three light testers are awesome, cheap and make it dead simple to check common wiring faults. In fact the several times I've done rough-in inspections on my house wiring the inspector always uses one of those to check outlets.
FYI, code these days require GFI in all potentially wet locations, including the kitchen, bathroom, garage, outdoors and detached structures. AFI are required in all common areas such as dining and living areas. GFI on branch circuits can either be provided by a dedicated GFI breaker (what I do) or GFCI outlet (cheaper). To extend protection to downstream outlets the outlet needs to be the first on the circuit. There is a limit to how many downstream outlets can be protected by I forgot how many.
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I'm pretty sure that only receptacles on kitchen countertops or within 6 week of the edge of a sink need GFCI protection. My fridge and stove are not GFCI-protected, but they are on dedicated single-outlet circuits and are more than six feet from the sink. I don't think there is any such exception for basements or garages, which is problematic for refrigerators and freezers in these locations (to me anyway).
edit - I just checked and it looks like the latest version of the NEC does in fact require all kitchen receptacles to be protected; I expect people to be really pissed off when they find their refrigerator GFCI tripped when they get get back from vacation.
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Code here requires a dedicated AFGF branch for kitchen fridge installation just to help avoid inadvertently tripping a circuit with the fridge on it while using a vacuum in another area, for example.
Cheers!
Cheers!
If the wiring is metallic shielded (commonly called BX), and the box is metal, it's likely that changing out the outlet to a grounded type would work just fine. You can test this just by using an ohm meter and test for continuity between the metal receptacle box and the white neutral wire.
You can use a GFCI outlet just in case and that would trip if you have a situation that an equipment ground would have saved you from. In other words, in a true grounded situation, a hot wire shorting to the cabinet of an appliance would immediately cause a dead short and trip your normal breaker. If that happens in an ungrounded connection, the GFCI senses the missing current and trips it locally.
You can use a GFCI outlet just in case and that would trip if you have a situation that an equipment ground would have saved you from. In other words, in a true grounded situation, a hot wire shorting to the cabinet of an appliance would immediately cause a dead short and trip your normal breaker. If that happens in an ungrounded connection, the GFCI senses the missing current and trips it locally.
