Re-wiring outdoor sign


Old 10-26-17, 03:11 PM
Thread Starter
Join Date: Mar 2001
Location: Kansas City Area
Posts: 233
Received 0 Votes on 0 Posts
Re-wiring outdoor sign

I will be re-wiring a lighted outdoor sign soon. The sign is essentially 3 large separate letters attached to the building. Power is supplied via rigid conduit to the first enclosed letter, then from the 1st to the 2nd & so on to the 3rd, rigid conduit between each. The existing wire size & breaker limits are matched correctly, 12g & 20 amps respectively.

The prior "electrician" (not) clipped off the end of the male plug and wire nutted the hot & neutral conductors. I can't & would not do that. This is especially true since LED light strips we plan to use have a transformer as part of the male plug end. My plan was to mount a shallow depth box inside the sign enclosure, wire a standard duplex outlet, then plug the LED lights into that. We wish to use LED light strips because the flexibility to zip tie the lights around the interior of the sign fixture and the possibility of different colors for different seasons.

Is it OK for the 2 THNN wires to be loose within the sign enclosure? Right now the conduit ends / terminates just inside the metal edge of the sign, thus those wires are loose currently. I would have them run loose to the shallow depth box, then of course make my connections using the duplex outlet. 2 wires screwed to the outlet coming in, then 2 wires screwed to the outlet going out to the next fixture / sign.

Would there be any benefit to using a single outlet plug, not a duplex? is there a special outlet manufactured for use specifically within such a fixture that would be better or easier to use?

Your help & suggestions greatly appreciated. Thanks Mike
Old 10-26-17, 09:27 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,874
Received 1,342 Votes on 1,240 Posts
Is it OK for the 2 THNN wires to be loose within the sign enclosure?
Yes.... the sign is a grounded enclosure and THNN is considered high heat wiring.

It sounds like non-sign rated power supplies are being used..... otherwise they would be hard wired.

I would consider it ok to install a shallow gem box directly to the metal sign and install a standard receptacle. Single or duplex is fine. I would install a rubber grommet or snap grommet in the box to bring the wiring in.

Technically the conduit should go directly to the electrical box but I believe you are ok in what you propose.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: