Contactor

[Matt Mckenzie]

If a 2 pole lighting contactor is only rated 30 amps can you install one 20 amp circuit at each pole? Only two maximum 15 amp circuits can be installed? A 40 amp rated contactor has 3 poles..... Maximum 13 amps per pole would be all you can install....?

 

[iwire]

If a 2 pole lighting contactor is only rated 30 amps can you install one 20 amp circuit at each pole? Only two maximum 15 amp circuits can be installed? A 40 amp rated contactor has 3 poles..... Maximum 13 amps per pole would be all you can install....?

It is per pole.

Each pole can handle and is rated for the nameplate current.

 

[petersonra]

Each Pole can handle the rated current. Keep in mind that in general you have to open all ungrounded conductors. So if you had a single phase ungrounded source you would need two poles. An example of this would be 240 Line to Line. If you are running 277 line to neutral you could in fact control 3 circuits with a 3 pole contactor.

 

[Sahib]

The amps rating per pole of contactor may change with nature of lighting load such as tungsten or florescent. Consult contactor manufacturer.

 

[iwire]

The amps rating per pole of contactor may change with nature of lighting load such as tungsten or florescent. Consult contactor manufacturer.

That info is on the labeling, no need to contact anyone.

 

[iwire]

in general you have to open all ungrounded conductors.

Not really the case with a contractor, about the only application I can think of that is required is HID lighting circuits.

 

[augie47]

Not really the case with a contractor, about the only application I can think of that is required is HID lighting circuits.

not challenging your statement but why is HID different ?

 

[iwire]

not challenging your statement but why is HID different ?

I don't know why so but

410.104 Electric-Discharge Lamp Auxiliary Equipment.



(B) Switching. Where supplied by the ungrounded con-ductors of a circuit, the switching device of auxiliary equip-ment shall simultaneously disconnect all conductors.

 

[augie47]

I don't know why so but

The Code reference or manufacturing input was the "why" I was looking for. Thanks
(another educational morning)

 

[iwire]

The Code reference or manufacturing input was the "why" I was looking for. Thanks
(another educational morning)

For me as well.

 

[kwired]

Fluorescent lighting is electric discharge lighting, but is nearly always supplied with a circuit utilizing a grounded conductor.

HID though most of the time is supplied by a circuit utilizing a grounded conductor is more often found with only ungrounded supply conductors then fluorescent lighting is.

You very seldom run into fluorescent lighting connected to 208, 240 or 480 volts but may occasionally find HID's on these voltages.

 

[Sahib]

You very seldom run into fluorescent lighting connected to 208, 240 or 480 volts but may occasionally find HID's on these voltages.

However, in case tungsten bulb is connected to 240v, not disconnecting all ungrounded conductors with a contactor as suggested is a safety hazard. Isn't it?

 

[kwired]

However, in case tungsten bulb is connected to 240v, not disconnecting all ungrounded conductors with a contactor as suggested is a safety hazard. Isn't it?

I don't see it as any more or less of a hazard as other lamp types. 240 volt HID (with no grounded conductor in the circuit) puts anyone changing a lamp at similar risk. Most HID's with magnetic ballast have one line of the supply circuit connected directly to one side of the lamp, it is normally the grounded conductor, when there is one, that connects directly to the lamp.

 

[iwire]

However, in case tungsten bulb is connected to 240v, not disconnecting all ungrounded conductors with a contactor as suggested is a safety hazard. Isn't it?

In general the NEC requires a disconnecting means to open all ungrounded and sometimes grounded conductor.

In general the NEC does not require that of controllers. A contactor is one form of controller.

As long as you are aware of that life is good.