Double Taps - InspectionNews

Tom Rees · #1 (**permalink**) 03-19-2010, 06:15 AM

How can you tell which Square D breakers are designed for two wires at screw down?

Rick Cantrell · #2 (**permalink**) 03-19-2010, 06:19 AM

If you got really, really good eyes, you might be able to read it on the breaker, or you can look at the terminal clamp.

Jim Port · #3 (**permalink**) 03-19-2010, 07:21 AM

Sq D 15-30 amp breakers are listed for one or two conductors. Larger sizes are for one conductor only.

John Dirks Jr · #4 (**permalink**) 03-21-2010, 06:24 PM

Here is whats printed on the side of the SQ-D's.

John Dirks Jr · #5 (**permalink**) 03-21-2010, 06:27 PM

That pic was too small. Here's another.

Chap Fichera · #6 (**permalink**) 03-22-2010, 03:52 AM

But that's only for the same gauge wire on each breaker?

James Risley · #7 (**permalink**) 03-23-2010, 01:39 AM

Quote:

Originally Posted by Chap Fichera

But that's only for the same gauge wire on each breaker?

Different size wires within the stated range on the breaker can be used. Note that one wire can be used so that the total absence of the second wire will not affect the proper clamping of the first wire. The radius of the positioning formation of the clamp is such that it will provide the proper contact area for those stated wire sizes. That is to say the use of a smaller guage wire under the clamp (be it one or two wires) cannot be used because proper clamping force between the clamp and the wire cannot be accomplished. A wire size larger than the stated size (be it one or two wires) cannot be used because the surface area contact between the clamping surfaces and the wire(s) would not be sufficient due to the radius of the positioning formation being two small for the larger wire(s). Depending on the design of the clamp some breakers and other devices may not be as restrictive of wire size ranges but allowable wire sizes should be indicated on the device.