Track lighting load article 410.

[Npstewart]

Article 220.43(B) addresses track lighting loads for services but not for branch circuit loading. Article 410.151(B) does address branch circuits but only mentions the connected load on lighting track shall not exceed the rating of the track light. But how do you actually determine how much load you can put on one branch circuit? Im sure it is permissible to use 220.43 but it doesen't explicitly say in 410 that you should or have to.

So if you have 100 feet of 120v single circuit track light, how many 20A circuits does this require?

According to article 220 at the service level this would be 100 feet * 75va/ft = 7500 va.

 

[david luchini]

There is no length limit to how track can be put on one branch circuit. 100 feet of (20A) track can be one 20A circuit...1000 feet of (20A) track can be one 20A circuit.

How much load you can put on the branch circuit is determined by 220.19(A) and 20(A). If your track lighting load is continuous, you would be limited to 1920VA. If the load is non-continuous, you would be limited to 2400VA.

 

[Npstewart]

Ok but how do you come up with the 1920 VA to begin with? What is that based on?

Also, I dont have a 220.19 in my book. Am I missing a page perhaps?

 

[david luchini]

Ok but how do you come up with the 1920 VA to begin with? What is that based on?

Per 210.19(A) and 20(A)...

1920VA * 1.25 = 2400VA = 20A @ 120V.

1920VA is the maximum continuous load you can put on a 20A, 120V branch circuit.

Also, I dont have a 220.19 in my book. Am I missing a page perhaps?

No...fat fingers. I meant 210, not 220.

 

[Npstewart]

I understand how you figure out that you can only put 1920 va on a single circuit.

How do you determine if you exceed that load given a certain length of track.

Lets say you have two lengths of track light:

Track #1 = 50 feet fed from circuit #1

Track #2 = 65 feet fed from circuit #2

What is the load on circuit #1 and circuit #2?

 

[david luchini]

I understand how you figure out that you can only put 1920 va on a single circuit.

How do you determine if you exceed that load given a certain length of track.

Lets say you have two lengths of track light:

Track #1 = 50 feet fed from circuit #1

Track #2 = 65 feet fed from circuit #2

What is the load on circuit #1 and circuit #2?

I dunno...what are the track head fixtures on each track? If I put thirty eight (38) 50W track heads on track #1, I'm OK. If I add a 39th 50W track head to it, I've exceeded 1920VA. Track is not a load, track lighting fixtures are.

 

[Npstewart]

Exactly, that answers my question.

Thanks Dave. I just wanted to make sure that I had that correct. The NEC handbook never mentioned anything about using the actual lamp load for branch circuit calcs, they just kind of dance around it.

 

[jumper]

Track is not a load, track lighting fixtures are.

Well technically all conductors, wire or bussbar, are a load due their characteristic impedances...small...but a tiny load none the less... Course the NEC does not include this in the calc.

David will now provide numbers that will drill me to the spot for being a wise acre...