How well do you know the Code? Think you can spot violations the original installer either ignored or couldn't identify? Here's your chance to moonlight as an electrical inspector and second-guess someone else's work from the safety of your living room or office. It's your turn to identify the violation.
Hint: One, two, three strikes you’re out!
Find the Answer
Gus J. Mininberg of High Voltage Electric Service, Inc. in Albany, N.Y. shared this photo of some wires “tripled-up” under some terminals. According to Mininberg, this is a 400A molded-case circuit breaker he found installed this way. If the terminals are too big for your wire, no problem, just double-up….no wait…make that triple-up the wires to make them fit! Well, at least that’s what this installer apparently did.
This installer also created a Code violation in doing so. Section 110.14(A) states that terminals for more than one conductor must be identified as such. Looking at the size of these terminals, I doubt that they are rated to accommodate such a small wire size. That is probably why the installer needed to jam some extra wires under each terminal. This can result in poor connections, which, in turn, can overheat the wires and terminals, creating a possible fire hazard.
I also question whether or not this wire is properly protected against overcurrent. It seems awfully small for such a large breaker size. Section 240.4 generally requires conductors to be protected in accordance with their ampacities.