This is meant to be a general question - I'm not asking about any specific breaker. More of a practical methodology question.

Some breakers are clearly labelled as to whether or not they accept a double tap (two wires under one screw / clamp).

But if there are no markings or they are illegible, which seems to be common with older breakers I have seen, is it likely to be acceptable to assume a double tap is or is not okay based on the shape of the terminal clamp?

In this example there are clearly two 'slots' where the wires are meant to go:

enter image description here

Would seeing such a clamp (or similar) guarantee that this is OK to do?

  • Can you provide a photo of the breaker overall? – ThreePhaseEel Aug 23 '18 at 23:00
  • What do the labeling and instructions say? What make of panel/breaker is it? – Harper - Reinstate Monica Aug 24 '18 at 0:28
  • @Harper thanks for your comment, made me realize I wasn't phrasing my question well enough. I've edited to try & clarify. – StayOnTarget Aug 24 '18 at 11:24
  • @ThreePhaseEel hopefully my question edits made it more clear why I used such a cropped portion; but I'll try & find the full photo & add it for better context. – StayOnTarget Aug 24 '18 at 11:25
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    Yes, a larger photo would let us recognize the breaker type and go "oh yeah, Pushmatics do allow that". – Harper - Reinstate Monica Aug 24 '18 at 12:50

In my opinion the particular breaker terminal you are showing, is legal for connection of two conductors. The only residential breaker that I know of that has this feature is a Square D Type QO. Maybe a Cutler Hammer Type CH, I think?

Regardless, it doesn't matter what my opinion is unless it is the AHJ agrees. I have had this discussion with local Inspectors many times and I can say that I have won about 50% of the time and lost 50% of the time.

In conclusion, check with your local authorities because what he allows and doesn't allow is really all that matters.

  • So I presume that some AHJ's might want to see an explicit label before they allow this, and others are more comfortable being pragmatic based on the visible characteristics of the terminal? – StayOnTarget Aug 24 '18 at 16:27
  • What does AHJ stand for? – donjuedo Aug 24 '18 at 17:11
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    @donjuedo - Authority Having Jurisdiction – Retired Master Electrician Aug 24 '18 at 17:35

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