Size 5 contactor temperature ?

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Davebones

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Have installed a 200 hp , 480 Volt air compressor . It has a ( size 5 Cutler-hammer AN16SNO ) starter . We're drawing about 235 amps continuously . Did a infared scan on the surface of the contactor and it shows around 180 degrees . Noticed the metal part of the coil that shows the coil info reads 230 degrees . Would these temps be considered high ?
 
Davebones said:
Have installed a 200 hp , 480 Volt air compressor . It has a ( size 5 Cutler-hammer AN16SNO ) starter . We're drawing about 235 amps continuously . Did a infared scan on the surface of the contactor and it shows around 180 degrees . Noticed the metal part of the coil that shows the coil info reads 230 degrees . Would these temps be considered high ?
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Assume you measuring in degC? Seems a bit hot to me but according to C-H it is rated for the application you have.
 
jumper said:
Our charts list both units.

We write and say degC here, but never use Celsius in everyday conversations.

We say I need 75C lugs to a fellow tradesman, but would say to neighbor that today will be hot, around 95, meaning degF.
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I'm sure you that my dear wife is from GA and, of course, grew up using degF for the weather (and everything else). She has been here 17 years and is somewhat familiar with temperatures being expressed in degC and that say, -4C, is likely to be frosty overnight. Oddly, we still express wind speed in mph.

We don't give a temperature rating for lugs, just a physical size to fit on the cable it's being used for and the hole size for making the bolted connection.
But back to the OP's point, I don't think his measured temperatures should be an issue. His highest temperature is about 82C.

For transformers we'd specify class F for design purposes and class C in operation. Maximum winding temperatures are 180C and 150C respectively to give a design margin. The OP's measured temperatures are a long way away from that which why I think he is safe.
 
Davebones said:
Have installed a 200 hp , 480 Volt air compressor . It has a ( size 5 Cutler-hammer AN16SNO ) starter . We're drawing about 235 amps continuously . Did a infared scan on the surface of the contactor and it shows around 180 degrees . Noticed the metal part of the coil that shows the coil info reads 230 degrees . Would these temps be considered high ?
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Are you having an issue that caused you to check this? Just curious.
I agree with others - should be ok.
 
You are well within the current rating of the contactor, but you must also consider the ambient environment. As open devices, the Freedom series contactors are rated for 65C ambient, which is 149F. An enclosed starter is rated for 40C /104 F. But that is the surrounding air temperature, not the device surface temperature. There is no rating for the device surface temperature. It's only in the age of IR scanners that people (outside of the component mfr) have even paid attention to that, but have nothing to go on.

More relevant is that Eaton uses coil magnet wire with Class B insulation, which is that 40C ambient plus a 90C allowable rise, so 130C maximum operating temperature. That's 266F. You are fine, but have little room left to spare.
 
No issue . This air compressor was at another plant that shut down . Been in service around six weeks just wanted to check for anything abnormal . Its in a enclosure and the room temp is in the mid 90's .
 
Jraef said:
You are well within the current rating of the contactor, but you must also consider the ambient environment. As open devices, the Freedom series contactors are rated for 65C ambient, which is 149F. An enclosed starter is rated for 40C /104 F. But that is the surrounding air temperature, not the device surface temperature. There is no rating for the device surface temperature. It's only in the age of IR scanners that people (outside of the component mfr) have even paid attention to that, but have nothing to go on.

More relevant is that Eaton uses coil magnet wire with Class B insulation, which is that 40C ambient plus a 90C allowable rise, so 130C maximum operating temperature. That's 266F. You are fine, but have little room left to spare.
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If you know what heat is dissipated inside the starter panel and the surface area available for that dissipation, and work out the internal temperature rise. I used to do that limiting the internal rise to 10C. If it was going to be more, I'd have the panel ventilated. More often than not, it had to be - but we were dealing with VSDs.

I don't know what it would be for a 200 hp fixed speed starter but I'd still be inclined too have it ventilated. Whatever, the OPs contactor seems to be fine.
 
Such equipment commonly operates at temperatures that can seem surprisingly high to some people.

If one lug is significantly warmer then the others - you probably have something you need to look further into.
 
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