Lighting Contactor Amperage

[mgardner]

Cutsheets for lighting contactors indicate that they are rated for 30Amps. Does these mean that each pole can support up to 30Amps or that the entire load across all poles can only be 30Amps?

Thanks

 

[jim dungar]

Each pole can carry the full rated current of 30A.

 

[mgardner]

Thanks Jim!

 

[charlie b]

Does these mean that each pole can support up to 30Amps or that the entire load across all poles can only be 30Amps?

Those two statements are saying exactly the same thing! Please do not think that 30 amps going across each pole of a two-pole contactor gives you a total of 60 amps. The 30 amps that are leaving one pole are exactly the same 30 amps that will be returning on the other pole.

 

[Smart $]

Those two statements are saying exactly the same thing! Please do not think that 30 amps going across each pole of a two-pole contactor gives you a total of 60 amps. The 30 amps that are leaving one pole are exactly the same 30 amps that will be returning on the other pole.

Not exactly!

He's asking if the current rating for the contactor is 30 amps total, e.g. 15A on each pole, or 30A per pole, e.g. two 30A L-N loads. He did not mention anything regarding load configuration... so it could 'give' you 60A total of L-N loading.

 

[dicklaxt]

Let me get a not eaxactly in here,,,,,,,,,,,,

This old man seems to recall if the loading per phase is 30amps/ leg then the neutral carries no current and the two phase loads in series is dropped across the two legs at 220v. or am I mistaken.

I vote for me and Charlie :happyyes:

dick

 

[infinity]

Also check that the 30 amps is suitable for the load being installed. Some contactors like the ASCO 917 have 30 amp contacts (general rating) that are only rated for 20 amps for certain type loads.

 

[Smart $]

Let me get a not eaxactly in here,,,,,,,,,,,,

This old man seems to recall if the loading per phase is 30amps/ leg then the neutral carries no current and the two phase loads in series is dropped across the two legs at 220v. or am I mistaken.

I vote for me and Charlie :happyyes:

dick

The answer to the OP has nothing to do with L-L or L-N circuit current. OP'er simply wants to know if a multi-pole contactor rating of 30A means 30A per pole or 30A total. Jim stated the answer correctly in the first reply.

 

[dicklaxt]

The answer to the OP has nothing to do with L-L or L-N circuit current. OP'er simply wants to know if a multi-pole contactor rating of 30A means 30A per pole or 30A total. Jim stated the answer correctly in the first reply.

Oh I certainly agree its 30amps qnd you know my statement doesn't hold water either unless its a common neutral which your thought didn't appear to be,,you got me, LOL but ain't this fun

dick

 

[Smart $]

Oh I certainly agree its 30amps qnd you know my statement doesn't hold water either unless its a common neutral which your thought didn't appear to be,,you got me, LOL but ain't this fun

dick

Yeh... as you can see, I've been having fun here for a while now :lol:

 

[charlie b]

OP'er simply wants to know if a multi-pole contactor rating of 30A means 30A per pole or 30A total.

And what would be the difference between the two? :? In what context does the word "total" come into play here? If you put two lights in parallel, with one drawing 1 amp and the other drawing 2 amps, then the two lights draw a "total" of 3 amps. But if you individually measure the amps flowing in each of the two poles of a 2-pole contactor, and if your meter gives you a reading of 15 amps in each case, are you going to conclude that the contactor is experiencing a "total" current of 30 amps? I hope not. This is not an "amps plus amps equals amps" situation. It is an "amps flowing out equal amps returning" situation.

 

[Besoeker]

Those two statements are saying exactly the same thing! Please do not think that 30 amps going across each pole of a two-pole contactor gives you a total of 60 amps. The 30 amps that are leaving one pole are exactly the same 30 amps that will be returning on the other pole.

With single phase, would you switch both live and neutral?

 

[Smart $]

... It is an "amps flowing out equal amps returning" situation.

But the amps flowing out through one [set of] contact doesn't necessarily return through another [set of] contact. It could be connected to all single phase L-N loads, where the current flowing out through contacts returns on unswitched, individual neutrals... or all L-L loads with only one leg switched (though this is not the typical configuration, but not prohibited by Code).

 

[charlie b]

With single phase, would you switch both live and neutral?

Single phase could be two pole (i.e., 208 volt), and thus not have a neutral. That was my interpretation of the question.

 

[charlie b]

But the amps flowing out through one [set of] contact doesn't necessarily return through another [set of] contact.

OK, I see where we are getting confused. Or maybe it is only me that is confused. :happyyes: I interpreted the question as dealing with a device that has two things that open and close together on command, and that serve a single load, so that current leaving the one will return via the other. You are talking about multiple sets of contacts, all operating together, but serving different loads. So that brings us back to Jim's original response, that any pole can handle 30 amps. Mea culpa.

 

[Smart $]

OK, I see where we are getting confused. Or maybe it is only me that is confused. :happyyes: I interpreted the question as dealing with a device that has two things that open and close together on command, and that serve a single load, so that current leaving the one will return via the other. You are talking about multiple sets of contacts, all operating together, but serving different loads. So that brings us back to Jim's original response, that any pole can handle 30 amps. Mea culpa.

Ding, ding, ding... you are a winner