Definite purpose contactor

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Location
Denver, CO
Ok sorry for the dumb question. I have a 30 amp, 4 pole definite purpose contactor. Square D.
Are these rated for 30amps across each contact, or 30 amps totaled across all 4 poles? Thanks in advance
 

augie47

Moderator
Staff member
Location
Tennessee
Just to make your day more interesting, note that most DP contactors are UR listed and as such are components of listed equipment and are not listed for 'stand alone" installations (although they are often used in that manner)
 

B4T

Senior Member
There is also a problem using definite purpose contactors for lighting.. not rated for it I was told..

But.. I have about (50) out in the field controlling lighting circuits before I heard that news.. :(
 
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T.M.Haja Sahib

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There is also a problem using definite purpose contactors for lighting.. not rated for it I was told..

But.. I have about (50) out in the field controlling lighting circuits before I heard that news.. :(
Can AHJ allow it?
 

Stevareno

Senior Member
Location
Dallas, TX
There is also a problem using definite purpose contactors for lighting.. not rated for it I was told..

But.. I have about (50) out in the field controlling lighting circuits before I heard that news.. :(
I have also used definite purpose contactors for lighting and I've never seen an inspector take issue with it.
I can maybe see an argument that the contactor coils aren't rated for continuous duty. All lighting specific contactors I have seen have been mechanically held or 'pulse' controlled.
I may have to take a closer look at the coil ratings next time I get my hands on a contactor.
 
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renosteinke

Senior Member
Location
NE Arkansas
"Lighting contactors" are subjected to a huch higher inrush current test. You're not supposed to use 'definite purpose' contactors for incandescent or (especially) HID lighting. Supposedly, the contacts might not last long.

I agree, though .... there are plenty being used as such, and without much trouble. A very common use is to use the contactor to allow a single photo-eye to control many lights. It's also a convenient way to put in a 'test' or 'manual' control.

UL is in the business of testing complete assemblies, rather than the individual parts. Their mark on a component cannot say anything about the finished product.

I have heard of - but not experienced - some inspectors objecting to placing these contactors in pull cans, rather than 'control panels.'
 

kwired

Electron manager
Location
NE Nebraska
I have heard of - but not experienced - some inspectors objecting to placing these contactors in pull cans, rather than 'control panels.'
Once you put a contactor in it - it becomes a control panel.

I can maybe see an argument that the contactor coils aren't rated for continuous duty.
There are many DP contactors in listed equipment that get continuous duty use.

I understand the fact that they may not be tested for use as lighting contactors. I also think it is just stupid if they can't be used as lighting contactors. As has been said they have both resistive and inductive current ratings. Suddenly a light or a motor not installed as part of a piece of listed equipment has different properties than one that is part of listed equipment?
 
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