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One of the old electrical sockets needed to replaced. It was a Slater brand, with only the option to push-in wires at the back with no screws for hot/neutrals and only one screw for ground. Both the top and bottom plugs were switched off by the same circuit breaker.

I noticed there were two sets of wires coming into the outlet box (one set of black, white and ground; another set of black, white and ground, with the two grounds tied together). Both sets were connected to the outlet (not pigtailed). After disconnecting the wires, I used my multimeter to check across the two Hots on the old outlet, it read 0.0 Ohm and it also read 0.0 Ohm across the two Neutrals.

I installed a new outlet in which I used screws to connect the wires (as opposed to the push-in). I left the connecting tab between the two plugs as is. I switched on the circuit breaker and things appear to be working just fine.

I read through posts related to this on this forum and elsewhere but it isn't clear to me if there is any potential issue with this config.

I understand that leaving the tab in place is the same as what was before. But, is this the right thing to do? Could you please comment?

Thanks.

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With an ordinary duplex receptacle (GFCI is a bit different), there are two ways it can be installed:

  • Combined = tabs in place

In this mode, the two hots are connected together and the two neutrals are connected together. Both receptacles are powered from the same source. If you want to power an additional receptacle (or lights or whatever) from the same power source, you can use the second set of screws (or backstab connections, but those are not recommended) as a way to daisy-chain to the next device. Alternatively, you can also chain to another device using pigtails with a single set of hot/neutral wires & screws.

  • Split = tabs removed

With the tabs removed, you have two totally separate receptacles. Each can be on a different circuit! Except not entirely - for safety reasons the circuits should be together, typically using a Multi-Wire Branch Circuit (MWBC). An MWBC uses two hots with one neutral - the hots each 120V compared to neutral but 240V compared to each other. In the case of an MWBC, the neutrals are actually shared, so you would not remove the neutral tab, just the hot tab (and there are other complications which mean that neutral would itself be on a pigtail even if only one other device is connected).

There is another use for removing the tabs - a half-switched receptacle. With this configuration, hot goes to one hot screw and switched hot goes to the other hot screw. Neutral still gets one wire and the tab is left in place. This lets you use a plug-in lamp with a switch while still having an always-on receptacle for other stuff. Personally, I prefer ceiling fixtures, but builders like to save every $ they can...

The end result is that the hot-side tab is removed in certain specific cases but the neutral-side tab is hardly ever removed - only realistic case I can think of is a top/bottom MWBC split on a double-breaker GFCI.

And since your original didn't have the tabs removed, the replacement doesn't either.

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    Thank you! Your explanation makes sense. The thing I had not checked was whether both of the black wires were hot after disconnecting them from the outlet. I think only one of them is hot and the other acts as a source for other elements which are daisy-chained to this receptacle. Thanks again for taking the time to write your post.
    – user127111
    Dec 14, 2020 at 5:57
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    @user127111 please note that the appropriate way to say "thanks" is to up vote each answer that helps you and click the check mark of the answer that helps you the most. (All explained in the tour.)
    – FreeMan
    Dec 14, 2020 at 14:22
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    I'd like to thank you for the reminder about MWBC- since it isn't THAT common, I'd forgotten about that particular niche. When I learned from my grandfather (decades) mostly it was to permit outlets in the bathroom to be able to run a hair dryer or other high-amp device without blowing. Now with GFCI/AFCI and code requiring two circuits I wonder how common it is anymore.
    – J.Hirsch
    Dec 14, 2020 at 20:18
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    GFCI/AFCI is the biggie, since from a practical standpoint you can only get the MWBC-save-a-wire benefit if you put GFCI/AFCI at the breaker. Makes sense for a bunch of reasons for AFCI. But GFCI really works best at point-of-use so you can reset easily. I don't even have any MWBC myself - I've learned all about it here from Harper and others! (But I do have GFCI, of course.)
    – manassehkatz-Moving 2 Codidact
    Dec 14, 2020 at 21:34
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    @J.Hirsch I've got a MWBC outlet 3' from me. With all my computer equipment plus a room air conditioner I was getting occasional breaker pops especially from the surge load of a laser printer. The electrician running another circuit pointed out the low additional cost of running a MWBC, this lets the laser have it's own line.
    – Loren Pechtel
    Dec 15, 2020 at 1:11

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