The need for a lighting contactor.

[PistolP]

I was approached by a friend of mine that has a new business and when the sign guys hung the sign on the front of building informed her that there was no power run for the sign. She had a couple of contracts give her a bid on doing the work. One told her that she was going to need a lighting contactor and the other one said she could just use a switch. The sign is made of many LEDs and what she tells me is that she was told that total amperage is 4 amps on 120v. She asked me I told her I'm not sure, because I'm not sure if Leds would have an inrush of current upon being turned on.I am curious on what the requirements for a lighting contactor are in this situation.

[ActionDave]

Welcome to the forum.

There is never a requirement for a lighting contactor. There may be advantages to using one. From what you describe a simple switch would be fine.

[jumper]

If this was an existing commercial occupancy, there should have a sign circuit already if it was wired under recent codes. NEC 600.5.

[tw1156]

Illinois looks to have adopted the IECC 2015, but I'm unable to locate Red Bud's requirements. In looking at IECC 2015, the following requirements would come in to play here:

C405.2.5 - Exterior Lighting Controls. Lighting for exterior applications other than emergency lighting that is intended to be automatically off during building operation, lighting specifically required to meet health and life safety requirements or decorative gas lighting systems shall:

1. Be provided with a control that automatically turns off the lighting as a function of available daylight.
2. Where lighting... (this section not applicable)
3. Where not covered in Item 2.... (this section not applicable)

All time switches shall be able to retain programming and the time setting during loss of power for a period of at least 10 hours.

I understand this to mean the exterior electric signage to be controlled via photocell/timeclock. Looking further into IECC though, you do not have to include this signage as part of the exterior lighting allowance per the following:

C405.5.1 - Exterior Building Power - The total exterior lighting power allowance.....
Exception: Lighting used for hte following exterior applications is exempt where equipped with a control device independent of the control of the nonexempt lighting:
1....
2. Advertising Signage or directional signage.

In my opinion the IECC is sending a conflicting message here as the exterior building power requirements only note that a separate control is required (and does not reference the section with it being part of a function of daylight). I could see this argued either way, but I would recommend it be placed on some sort of timeclock to automatically control the circuit.

[AKElectrician]

All the contactors I put in were either over 30 Amps, or controlled by a photocell.

[jeremysterling]

C'mon folks, just wire it to a simple timeclock, like an $40 in-wall astronomical timer. Done.

[AKElectrician]

C'mon folks, just wire it to a simple timeclock, like an $40 in-wall astronomical timer. Done.

Do those account for huge swings in daylight? Where I live it is light right now at 8-9am depending on cloud cover. Soon it'll be light enough at 4-5am to where lights are not needed.

[ActionDave]

Do those account for huge swings in daylight? Where I live it is light right now at 8-9am depending on cloud cover. Soon it'll be light enough at 4-5am to where lights are not needed.

Programmable time clock or series a simple mechanical time clock with a photo cell.

[AKElectrician]

Programmable time clock or series a simple mechanical time clock with a photo cell.

Or a photocell and a contactor then when the power goes out for hours your not having to reset anything. Replaced more timers than contactors...

[George Stolz]

With an Intermatic EI600 you can set the latitude more conservatively or liberally if desired to account for cloud cover, and have the added benefit of being able to shut the sign off at closing time, or manually override it at will without electrical tape. They are not bothered by power outages; even pulling out the battery to replace it doesn't lose the time or programming.