4 parallels 3 conduits

[RUWired]

Interesting find today surveying a pad mount transformer to MDP.Conduit 1 contained 2 A's,B,C.N. Conduit 2 contained 2 B's,C,A,N. Conduit 3 contained 2 C's,A,B,N. Notice it is short a neutral. What a great way to pack in an extra run, but a 310.4 violation.
Rick

 

[eric stromberg]

This must be more common than i thought. I was inspecting a project some years ago when i noticed three nipples on top of an incoming section for a MCC. I knew there were four conductors per phase so i asked the contractor what the plans were. He told me "AABC, ABBC, ABCC." I told him to install another nipple and run it "ABC, ABC, ABC, ABC." He told me it wouldn't look very good because of the spacing. I told him i didn't mind how it looked.

On the same project i saw a transformer that had twelve holes in the bottom plate for the secondary (four conductors per phase). The plate looked a little strange to me and so i checked it with a magnet (i keep a magnet on my keychain). Sure 'nuff, ferromagnetic. I told the contractor that he had his choice between replacing the plate with an aluminum plate or changing the holes such that there were four large holes for the bundles to go through.

It's amazing how many times i see single conductors pass through ferromagnetic material. One time i saw single conductors being dropped through different rungs of a (steel) cable tray.