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Discussion Starter · #1 ·
120volt - 30 amp circuit. When is this a practical installation? High bay lights, parking deck pole lights, maybe a set of high powered lights wayyyy out on a dairy farm? Never did one in any new commercial jobs, never seen one in a resi job, but I have heard talk of them and I am looking right at 210.23 (B), so I know someone has some experience with them.
 

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120volt - 30 amp circuit. When is this a practical installation? High bay lights, parking deck pole lights, maybe a set of high powered lights wayyyy out on a dairy farm? Never did one in any new commercial jobs, never seen one in a resi job, but I have heard talk of them and I am looking right at 210.23 (B), so I know someone has some experience with them.
Parking lot lighting.

stadium lighting.

Just think of the stadium lights at today's football games each one of those lamps on those big banks of lights are probably 1500Watt metal Halide lamps.:eek:

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210.23(B) 30-Ampere Branch Circuits. A 30-ampere branch circuit
shall be permitted to supply fixed lighting units with
heavy-duty lampholders in other than a dwelling unit(s) or
utilization equipment in any occupancy.

A rating of any one cord-and-plug-connected utilization equipment shall not
exceed 80 percent of the branch-circuit ampere rating.

(C) 40- and 50-Ampere Branch Circuits. A 40- or 50-
ampere branch circuit shall be permitted to supply cooking
appliances that are fastened in place in any occupancy.
In other than dwelling units, such circuits shall be
permitted to supply fixed lighting units with heavy-duty lampholders,
infrared heating units, or other utilization equipment.

(D) Branch Circuits Larger Than 50 Amperes. Branch
circuits larger than 50 amperes shall supply only nonlighting
outlet loads.
 

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I think anything with heavy duty lampholders-- so yes high bay fixtures, parking deck, etc. Now lets look at what a heavy duty lampholder is...

210.21(A) Lampholders. Where connected to a branch circuit having a rating in excess of 20 amperes, lampholders shall be of the heavy-duty type. A heavy-duty lampholder shall have a rating of not less than 660 watts if of the admedium type, or not less than 750 watts if of any other type.
 
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Discussion Starter · #4 ·
I think anything with heavy duty lampholders-- so yes high bay fixtures, parking deck, etc. Now lets look at what a heavy duty lampholder is...
So 210.21(a) is THE requirement for if a light fixture can be put on a 30 amp circuit. Good to know. :thumbsup: Is there anything other than a heavy-duty light fixture which would require a 120volt 30 amp cicuit? Any oddball motors, or is this the only application?
 

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So 210.21(a) is THE requirement for if a light fixture can be put on a 30 amp circuit. Good to know. :thumbsup: Is there anything other than a heavy-duty light fixture which would require a 120volt 30 amp cicuit? Any oddball motors, or is this the only application?


I was at a warehouse last week with 120V 30 amp lighting circuits to the HPS fixtures. All circuits carrying near the max 26 amps. All the breakers feeding the lights were over 200 degrees. This was a 225 amp GE BR style panel. Not sure if bolt in breakers would operate any cooler.
 

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Didnt know that!:eek: I assumed the were 240v.
The adapter you can buy at the RV store converts the 30A cord to a 20A so you can plug your RV into a "normal" outlet. But, with the 30A you can run your A/C & microwave at the same time. :) I suppose some bigger RV's have 50A/220V requirements, but I can't remember the last time I wired one for that.
 

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Discussion Starter · #9 ·
The adapter you can buy at the RV store converts the 30A cord to a 20A so you can plug your RV into a "normal" outlet. But, with the 30A you can run your A/C & microwave at the same time. :) I suppose some bigger RV's have 50A/220V requirements, but I can't remember the last time I wired one for that.
I've never touched an RV outlet before, but thats good to know. All the more reason to buy 1 or 2 SP 30 amp brk's and throw 'em in the van. Thxs:thumbup:
 

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Is there anything other than a heavy-duty light fixture which would require a 120volt 30 amp cicuit? Any oddball motors, or is this the only application?
Read art. 210.23(B) -- it states heavy duty lampholders except in dwellings, etc or utilization equipment in any occupancy.
 

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120v 30A is a common server circuit also.

I don't know why though. They probably just figure more is better.
Server circuit as it generally will run a PDU. When my company has installed servers in the past in cooperation with the IT company, generally one full cabinet of equipment will be wired into a single 30A 120V PDU. With the ones we've done, the electric is run across the ceiling on unistrap and then a 30A twistlock connects to the receptacle on the ceiling.

30A 120V are also found in high energy lighting in theater applications, stage performances, and other entertainment venues. In fact, my other company has an amplifier for our stage systems that can support a 30A 120V. Our distros all have at least one L5-30 for this reason.
 

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120volt - 30 amp circuit. When is this a practical installation? High bay lights, parking deck pole lights, maybe a set of high powered lights wayyyy out on a dairy farm? Never did one in any new commercial jobs, never seen one in a resi job, but I have heard talk of them and I am looking right at 210.23 (B), so I know someone has some experience with them.
Just a couple of things to mention, code wise I think you are fine.

Design wise voltage drop is more of an issue as you load the circuit heavier.

If you break the circuits up and one has a short they don't lose all the lighting. This may not be a problem in this case but it is something to think about. We do a lot of large site lighting and we do not use one circuit to light an area, we mix the circuits up in case one circuit fails you still have light.
 
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