Modern electrical outlets - side wiring with 12 gauge

[Frank Pratt]

While I have had several "1"s fail, I have never had a "3" fail, and have never used a torque wrench. I just can't see why "3" would would be more likely to fail than "2".

Because you have 2 wires instead of 1 trying to torque the screw loose when the receptacle is pushed back in the box. Especially with #12 wire. I've personally seen it happen when installing one way back in the day.

[Stephen Tashiro]

Because you have 2 wires instead of 1 trying to torque the screw loose when the receptacle is pushed back in the box.

I don't understand why 2 wires would be involved in loop wiring a screw in a receptacle. Doesn't (proper) loop wiring only involve looping a single wire around a screw? (And using pigtailng to avoid having more than one wire per screw).

[Doug Dawson]

I don't understand why 2 wires would be involved in loop wiring a screw in a receptacle. Doesn't (proper) loop wiring only involve looping a single wire around a screw? (And using pigtailng to avoid having more than one wire per screw).

Another way to look at it is to consider that the highest stress the wire is under is when it's being pushed back into the box. In the case of side-wiring, that pressure is exerted to at least hold the wire in place, whereas with loop wiring, it is to push it away from the screw.

It's worth noting here that even experienced electricians have difficulty free-handing the tightening of the screws to within 10 percent of spec. Here's an interesting discussion of that: https://www.youtube.com/watch?v=H21lZxyvMNw

[Frank Pratt]

I don't understand why 2 wires would be involved in loop wiring a screw in a receptacle. Doesn't (proper) loop wiring only involve looping a single wire around a screw? (And using pigtailng to avoid having more than one wire per screw).

I may have interpreted #3 incorrectly, but I took it as referring to a situation where more than one receptacle i in a box. In that case, one could strip off a bit of insulation mid-wire, bend it into a U, and put it under the screw. The remaining tail then goes on to feed the next receptacle.

[Brian Elfert]

Ever used the Pass & Seymore Plugtail system? The receptacles come with a pigtail harness consisting of stranded wire leads that terminate in a plug that connects to the receptacle. the tails are connected to the wires after pulling them in & then at finishing stage, the receptacles are plugged into the tails.

The advantages being easy device replacement without shutting the power off and a circuit can be energized without having all the receptacles installed. Pricey though, but they are spec grade.

Are these for residential or commercial? How often does someone replace receptacles in a house to need a pigtail to make it easier?

[Frank Pratt]

Are these for residential or commercial? How often does someone replace receptacles in a house to need a pigtail to make it easier?

Could be either, but the are a higher end product & expensive.

[Brian Elfert]

Could be either, but the are a higher end product & expensive.

I could see maybe using in commercial environment if receptacles are going bad regularly due to heavy use. I don't see why it would be worth it for residential as receptacles shouldn't need replacement for several decades at earliest. My parent's house was built in 1979 and the receptacles are all original. My house was built in 1980 and many of the receptacles had no tension anymore. (Most of the stuff in the house was cheap and had to be replaced.) I replaced every switch and receptacle in the house. I bought a better grade of receptacles since the total additional cost for the whole house was maybe $30.

[Wade Lippman]

Because you have 2 wires instead of 1 trying to torque the screw loose when the receptacle is pushed back in the box. Especially with #12 wire. I've personally seen it happen when installing one way back in the day.

I understand your point. I always squeeze the loop together; I just can't see it doing much of anything.

[Doug Dawson]

I understand your point. I always squeeze the loop together; I just can't see it doing much of anything.

Squeezing the wire around the screw is the way to go, no doubt, if that’s what the receptacle requires. But the length of wire, however short protruding from the box, might dictate that you’re better off side-wiring (under the clamp,) and your life is made easier by using receptacles that support that.