Light Switch: Push In As Good As Screw Terminals ?

Robert,

I wouldn't use the push-in connections on switches/recepticles. I don't think they're even allowed by code anymore? They rely on a spring contact which could theoretically weaken over time, allowing overheating, arcing, fires, etc...

In any case, the screw terminals will provide a stronger, more reliable connection. Just remember to wind the wire around the screw in the direction the screw turns.

My favorite switches/recepticles are the ones that use a clamping plate under the screw. You simply strip the wire, insert it under the plate, and tighten down the screw. The ease of the push in connectors, with the solid connection of a screw terminal. Best of both worlds. But, they do tend to cost slightly more. No biggy for one device, another matter when you have dozens to install... :)

Anthony

I have had several push in connections fail in my house. This how the house was constructed. The vacuum cleaner caused most of them. Of not in the plug it was plugged into, but further "upstream" which took some detective work to find.

You should ask either the governmental safety authority or the industrial standards association for the country where you live. One or the other may have tested the variety currently on the market.

I don't think the clamps are nearly as good as screw terminals; it is simply much easier for them to pull out. That said, I use them all the time. They are great with #10 wire, or when you are a bit short on wire as they require less wire; and there is less wire to bend up and shove in the box.

They are perfectly acceptable to UL and other fire/electrical safety organizations.

I've never had trouble with any push-in connections; but I still prefer a screw type terminal because it puts more metal surfaces in contact with each other.

The National Fire Protection Association (they write the National Electrical Code) has a project underway to see what happens as house wiring ages. It's got some years to go, but the results will help answer questions like yours.

TKM

They should have been pigtailed instead of daisychained.

Do not use the push in type unless you are using spec grade type where you push it in and screw down a plate on it (as described above).

Gee with these answers, I wonder how the manufactures get a UL listing with the push in connection?

I use the push in for light loads, like the one you described. I do not use them for outlets. I can and do plug some heavy loads into outlets occasionally. Pushin connections are not used with AL wire and you need a special device rated for AL wire. (just in case)

Oscar_Lives wrote:

Pigtailing is indeed best practice but with the exception of the neutrals of multi wire branch circuits it is not required.

True, but there usually isn't any "pulling" force inside an electrical box. And even with #14 wire, they clamp down rather tight.

In any case, I usually use the standard screw terminal devices just because of the cost.

Anthony

At best, I don't think the push-ins have as much metal-to-metal contact as a screw with a wire wrapped around it and tightened down.