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Square D breakers double tapped


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I thought I read that Square D breakers are allowed to be double taped due to their design. Is This writen spacificly into the code book?



Sort of, yes. Look at 110.3(B) which says that listed or labeled equipment is supposed to be installed in accordance with any instructions included in the listing or labeling.

Square D breakers are listed. Some of them (not all) included instructions, embossed right there on the breaker body, that tell you it's ok to install two wires on their terminals. If you do this, the wires must be both be copper, though they can be solid or stranded (or a combination of both). There are size limitations, but within those limitations you can use two different sizes of wire. (This usually isn't an issue, but it's permitted.)

By the way, the same is true for some Cutler Hammer breakers, but I'm not aware of any other manufacturerer, present or past, that has bothered to get their breakers listed for use with more than one wire.

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The NEC specifically prohibits non-intended uses in 110.14 (A)

110.14 Electrical Connections. Because of different

characteristics of dissimilar metals, devices such as

pressure terminal or pressure splicing connectors and

soldering lugs shall be identified for the material of the

conductor and shall be properly installed and used.

Conductors of dissimilar metals shall not be intermixed in

a terminal or splicing connector where physical contact

occurs between dissimilar conductors (such as copper and

aluminum, copper and copper-clad aluminum, or

aluminum and copper-clad aluminum), unless the device

is identified for the purpose and conditions of use.

Materials such as solder, fluxes, inhibitors, and

compounds, where employed, shall be suitable for the use

and shall be of a type that will not adversely affect the

conductors, installation, or equipment.

Informational Note: Many terminations and equipment

are marked with a tightening torque.

(A) Terminals. Connection of conductors to terminal

parts shall ensure a thoroughly good connection without

damaging the conductors and shall be made by means of

pressure connectors (including set-screw type), solder

lugs, or splices to flexible leads. Connection by means of

wire-binding screws or studs and nuts that have upturned

lugs or the equivalent shall be permitted for lOA WG or

smaller conductors.

Terminals for more than one conductor and terminals

used to connect aluminum shall be so identified.

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