Electrical – Is it ok to twist THHN together before installing in conduit


Is it ok (code compliant and not otherwise inadvisable) to twist two or more THHN conductors together (before running in conduit) ?

Issues I can imagine:

  1. EM fields cancel out. Not a bad thing.
  2. Twisting stresses the insulation jacket. Seems like you'd have to twist REAL tight.
  3. Causes excessive heat buildup – this one seems like it could actually be a concern.

I want to twist a couple of neutral-hot pairs together, to keep distinct within one conduit. Easy to do by chucking the two ends together in a drill. Should give a nice clean look.

Best Answer

Electricians never purposely twist wires together before installing them. As a matter of fact, we attempt to keep large conductors separate as they are pulled into the conduit so they do not twist around each other.

First, it is completely unnecessary for identification we just number the neutrals or tag them with some colored tape to indicate which phase conductor they go with.

Second, by twisting the conductors you are filling up more of the conduit and you are shortening the conductor. Using more wire to accomplish your purpose without a clear advantage is wasteful.

Third, the EM fields cancel out anyway without twisting. The reason Cat 6 cable is twisted is to reduce external signal transfer to the wire pairs not for EM cancellation between the pair.

Focus your time on something more productive.

Good luck and stay safe!