Double taps

Can Square D breakers be double tapped. There is a small lug that appears to be able to handle 2 wires, one on each side of the lug.

Some of the newer Square D Homeline breakers can be double tapped.

This is how I tell the difference: Single screw, and compression = Single wire
Single screw with compression plate = Double tap (not sure the actual term)

In this thread, the wires are installed poorly, but you can see in the photo the crimped plate below the screw.

This is what to look for:

twowirebreaker (Small).jpg

The Square D QO and Homline are good for 2 conductors in the 15 and 20 amp sizes.

Around here (Great Lakes/Upper Midwest), we call them saddle clamps. The terminology for electrical system components is not the same everywhere so they may known by other names elsewhere.

Jim what documentation do you have on this…I have been reading online from the square d site and have not found this info yet…

The listing is usually affixed directly to the breaker. When they are specifically listed for two conductors, it’s no longer referred to as a “double-tap,” unless both conductors are on the same side of the screw.

The term “double-tap” is generally reserved to describe an “improper connection.”

In this photo, from Mark Shunk in that old thread, you can clearly see the wire sizes and connections for the square D breaker:

and both wires have to be the same gauge. Had a electrician try to tell me the doorbell transformer(16 gauge strained) was ok on that 15 amp circuit with the #14 solid. Ask for his determination in writing, still don’t have it.:smiley:

Bruce do you think that’s true when you look at the installation graphic on the side of the Square D breaker in the photo? I see #14-#10 as permitted to be both landed on the breaker. Maybe I’m missing something but I don’t see any prohibition for different size conductors.

Square D single-pole. This breaker is rated for two conductors only, but many are rated for a single conductor only, so this is something to be aware of when inspecting the breaker. Square D and Cutler-Hammer currently manufacture breakers which are UL-listed for this application.

The label on the Square D breaker states that it is listed for one or two wires.

sq d breaker label copy.JPG

sq d breaker label copy.JPG

What about 2 neutral wires under one screw on the ground bar or a neutral and a ground wire together under one screw

You just have to be sure that if there is a three wire home run, both hot legs are not connected to the same breaker.

While commonly done in the past it was contrary to the UL listing. It has been spelled out now in the NEC so that the infomation is more readily available.

The rule is multiple grounding conductors are typically ok, but check the panel label. Neutrals must not share, nor be grouped with another conductor.

If you had a #14 and a #10 installed, how could you ensure adequate pressure and mechanical tightening on the #14? That’s why they ask for matched size conductors, so that equal pressure and holding power is on both sides of the saddle.

I don’t see where they ask for matched size conductors on the side of the breaker…only what sizes are allowed.

The little pressure plate on breakers rated for two conductors does not bind on the screw so the plate can pivot enough to clamp each conductor correctly.