Only 2-prong outlets in 100-yr old house

I just rented a studio apartment in a 100 year old house and belatedly noticed that the electrical outlets each have two 2-prong sockets. I’ve read some of the posts about checking if an outlet is grounded/ungrounded.

For each outlet, I plan to:

  1. Unscrew the face plate,
  2. Plug in a 3-prong to 2-prong adapter, (,
  3. Re-fasten the face plate screw through the metal ring on the adapter,
  4. Test with a circuit analyzer (

**Is it alright to plug in a 3–>2 prong adapter into each socket so that the outlet has two sockets, each with an adapter that is fastened to the face plate?

There’s only ONE outlet in the small kitchen (2-prong). If I recall correctly, the prior tenant had this set up:

I. One kitchen electrical outlet with two 2-prong sockets

1. Top 2-prong socket
      A. 3-->2-prong adapter plugged into top 2-prong socket but metal ring not fastened by screw to face plate.
           a. 3 outlet adapter (the kind that gives you three 3-prong outlets from one outlet) plugged into the 3-->2-prong adapter
                i. Gas range plugged into the 3 outlet adapter.

 2. Bottom 2-prong socket
      A. 2-prong 5 ft. household extension cord plugged into bottom 2-prong socket.
           a. 3 outlet adapter plugged into extension cord.
                i. Refrigerator plugged into the 3 outlet adapter
                ii. Microwave plugged into the 3 outlet adapter 

This whole set-up caused red flags to go off in my head. It seems like a BAD idea to have both the refrigerator and gas range on the same outlet, not to mention all the various connections. **Pls comment.

There is another two socket (2-prong) outlet in the dining room immediately adjacent to the kitchen. I was thinking I’d plug a 3–>2-prong adapter with a 15-ft heavy duty extension cord to it. Then, I’d run the extension cord into the kitchen, with a 5-outlet surge protector attached. I’d use the 5-outlet surge protector for the refrigerator, a small microwave and a coffee machine. **Is this a bad idea?

Any advice would be appreciated!

Well, you don’t really have much of an option if you’re renting the place.

  1. Make sure outlets are all grounded.
  2. Make sure the ground screws for the adapters are all connected.
  3. A circuit analyzer is a great idea.
  4. Extension cords as permanent solutions are frowned upon, but again, you really have no choice.

If fuses aren’t blowing or breakers tripping then you’ve done all you can do.

You’ll only be able to plug in and connect one adapter per outlet. If you plug in two with both adapters’ tab facing the center, one of the adapters will have a hot-neutral reversal.

The previous people had nothing grounded in the kitchen. You’d be better off installing one ground adapter, then plug in a three from one adapter or even a regular power strip. Better yet, use a GFCI adapter,so you’ll be safe even if the ground is iffy or missing entirely, which is a distinct possibility with really old wiring.


Because the bottom one would be upside down.

Most people ignore it, but that little green ring is supposed to be screwed to the faceplate screw. Back in the days of two prong outlets, people wired the house with conduit which came in really handy because it created a mostly unbroken electrical pathway from the outlet back to earth so when it was time to update to a ground the system extra wires didn’t need to be pulled. A few adjustments may have been needed to be made, but that was it.

Anyways, if you turn the bottom adapter upside down, hot and neutral are reversed. The only way to fix that is to either break the tab connecting the two outlets and wire one backwards. But at that point you might as well replace it with a grounded outlet and ground it to the metal box properly.

OP, if you happen to have a multimeter (or just pick up a $5 voltmeter at home depot). Make sure it reads 120 from the hot side (the one on the right) to the faceplate screw before starting. If it doesn’t, it’s not worth going further since it’s not grounded. I mean, you’ll physically be able to plug things in, but they won’t be actually grounded.

Ah! Good point.

That’s where the GFCI comes in - it doesn’t require a ground in order to protect you from shocks.

Thanks for your reply, Leaffan! I picked up a GFCI Receptacle Tester (it’s the only one the store had).

I only turned the gas stove off and on to see that it worked; haven’t tried cooking or baking yet. I’m really hoping it won’t be a problem.

Thanks for your input, gotpasswords. I understand now why there should only be one adapter per outlet. I didn’t know products like the Coleman Cable Extension GFCI Extension Cord existed; I’ll order one–maybe I should get one for each room.

I didn’t know that either, thanks!

I visited the studio today to take move-in condition pictures and notes. I was surprised to see that the “regular” outlets were comprised of two sockets each. However, instead of 2 prongs in each socket, there were 2 x 2 prongs in each socket. I’ve never seen these before and couldn’t find a picture on Google either. It looks similar to a 2-prong socket, but there’s one set of 2 vertical prongs on top and another identical set of 2 vertical prongs right below it.

Don’t know if this will display properly, but kind of like this:


I had to charge my camera battery (2 prongs on the charger) and plugged it into the top set of 2 prongs in one of the sockets. It seemed to work okay.

It actually looks like you could plug in four 2-prong plugs right below one another in the outlet.

I also found the Owner’s Manual for the Gas Range which emphatically states that it should only be operated using a properly grounded outlet. Uh oh…

Any comments on whether both the refrigerator and gas range can be plugged into the same outlet if I use the GFCI adapter as suggested?

I really appreciate the helpful responses already given!

Gas ranges use very little juice – just enough to run the clock and the electric ignition, supposing the range doesn’t have standing gas pilots.

And it’s not so much about whether the stove and fridge use the same outlet as it is about what else is on that circuit. If it’s only the fridge and stove, you should be fine, all things considered. You might investigate the fuse panel, and take out the fuses one at a time to see what outlets and lights go off for each fuse you take out. Mark the fuses accordingly to save yourself trouble the next time out.

Not necessarily, or even usually the case. Around here (Eastern Massachusetts) most houses with two-prong outlets have armored cable, or knob-and-tube. While the armor on armored cable theoretically can provide a ground, I don’t think in actual practice it’s much to be relied on.

The point is that just putting an adaptor on the outlet, even if you fasten the screw to the faceplate, is not guaranteed to create a ground. In many cases all you’re doing is making the outlet physically able to accommodate a modern three-pronged plug. Is this unsafe? It’s a matter of statistics, I suppose, but suffice it to say that the number of people killed every year by ungrounded wiring alone is tiny.

having the fridge on a GFI receptacle may trip it frequently when it starts. it is not needed for a fridge anyway. you don’t want to loose power to the fridge. no GFI needed for microwave.

you want to check your number of circuits and fuse/breaker amps. i was in an old place with one 15A circuit for the kitchen. if the microwave was going it would often blow the fuse when the fridge kicked on at the same time.

running fridge on an extension cord is not good. microwave not good either unless it is a short appliance extension cord (very beefy and short like 6 feet). if a different circuit in dining room (if have) then maybe have microwave in there.

Hi Sal Ammoniac,
Thanks for your input! I’d forgotten to look into the fuse panel.

Hi Johnpost,
Thanks for the advice. I think this kitchen also only has one 15A circuit, but it looks like its not grounded.

Thanks to all for the helpful suggestions and advice!

There is only one dual receptacle in the kitchen; it is located behind the refrigerator and gas range.

  1. Plug a 3–>2 prong adapter into the top outlet; fasten metal ring to the face plate with the metal screw; plug refrigerator into 3–>2 prong adapter.

  2. Plug a 3–>2 prong adapter (not attached by metal screw to face plate) into the bottom outlet; plug a 3–>1 expansion outlet into the 3–>2 prong adapter*; plug gas range into 3–>2 prong adapter.

*This was to move the outlet out so that the gas range plug could clear the refrigerator plug in the outlet above. Without moving it out, the gas range plug and 3–>2 prong adapter wouldn’t sit flush and leaned partially out of the outlet.

Q1.  This is the best solution I’ve come up that doesn’t involve the owner re-wiring the apartment.  Any other ideas or comments?
  1. Using the one dual receptacle in the adjacent dining room, I plan to run an extension cord along the wall/floor board and below the kitchen cabinets into the kitchen to provide power for the coffee maker and microwave oven. The extension cord(s) would be plugged into the dining room dual receptacle with a 3–>2 prong adapter.

    Q2. Would it be better to use a separate extension cord for each appliance or would it be okay to use one extension cord with multiple outlets on the end or with a multiple outlet strip on the end?

    Q3. Would it be better to just use a 2 prong household extension cord and forget about the 3–>2 prong adapter?

    Q4. I’ve seen different values for the maximum current (Amps.) per AWG gauge wire. For example, one chart listed 18.6A and another listed 20A for 12 gauge wire, 11.8A and 15A for 14 gauge. I understand that if I put multiple appliances on the same extension cord, I need to add up the wattage requirements to figure out what gauge the extension cord needs to be.

    Coffee maker + microwave oven = 8.5A + 5.8A = 14.3A total.
    For 14.3A, one charts says to use 13 gauge, the other lists 14 gauge. Which is correct?

I’d appreciate any input, thanks!

you want the range to be grounded.

put in 2 3prong->2prong adapters in fridge receptacle with one grounded. if you then plugged a 6 receptacle-from-duplex adapter in then all 6 positions are grounded. this may be a bit wobbly so you should only use it if you could stabilize it with a block of wood underneath.

get a 12 gauge extension cord closest to the length you need, place it where it won’t get stepped on ( use a cord channel for floor use if needed) or bumped or rubbed. use a single cord with a multiple outlet adapter on the end.