photocell wiring

[wishmaster68]

We have an old building that is 240 volt. The outside lights are 2pole 240. The photocell that was rated 208/240. This might be a stupid question but the photocell only has three wires. Black, white, and red. How does this work on 240v?

 

[480sparky]

It opens one (ungrounded) wire of the circuit.

 

[iwire]

It opens one (ungrounded) wire of the circuit.

I agree with 480sparky but will add if these are HID fixtures you have an issue with 410.54(B)

 

[SEO]

I agree with 480sparky but will add if these are HID fixtures you have an issue with 410.54(B)

Section 410.54(B) ?

 

[iwire]

Section 410.54(B) ?

Going from memory but if that is the section I am thinking of it requires the 'auxiliary equipment' (AKA the ballast) to have all ungrounded conductors opened.

 

[SEO]

Bob I must be overlooking the code section could you help?

 

[jeremysterling]

410.104(B)

I would think "all conductors" means the grounded one as well.

 

[SEO]

That looks like the code section, the way I read it the ungrounded conductors are switched. I was hoping Bob would reply .

Thanks jeremy.

 

[hurk27]

410.54(B) Switching. Where supplied by the ungrounded conductors of a circuit, the switching device of auxiliary equipment shall simultaneously disconnect all conductors.

I can see this read two ways:

1. where the switching device is fed by only ungrounded conductors, then the device has to switch all conductors?

2. where the switching device is fed by a grounded conductor (as in this case) doesn't need to switch all conductors?

Let the debate begin:grin:

 

[SEO]

hurk27 I think you mean 410.104 (B).