overload protection on air condensing unit

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kitsr

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AHJ requesting overload protection on ac condensor. Never been required to do this on ac unit.
The unit min cir amp is 23 amps, max cir breaker 40 amp.
RLA on compressor is 17.5 amps.
Does 440.52 (3) apply ? Is this required by code?
I used a 30 amp 2-pole switch as my disc. motor rated.
If 440-52(3) applies can I change the breaker to a 25 amp to meet this?
Any help or comments are appreciated.
 
The overload protection should be part of the unit.
If it is a factory unit with a NRTL listing, all you or the inspector should be concerned about is the MCA and Max OCP per 440.22(C)
 
kitsr said:
AHJ requesting overload protection on ac condensor. Never been required to do this on ac unit.
The unit min cir amp is 23 amps, max cir breaker 40 amp.
RLA on compressor is 17.5 amps.
Does 440.52 (3) apply ? Is this required by code?
I used a 30 amp 2-pole switch as my disc. motor rated.
If 440-52(3) applies can I change the breaker to a 25 amp to meet this?
Any help or comments are appreciated.
Click to expand...
440.52 applies... but overload protection is usually built into most condensor units. You'd have to refer to the schematic to verify. Lacking a schematic, check the documentation, and short of that, contact the manufacturer...
 
augie47 said:
The overload protection should be part of the unit.
If it is a factory unit with a NRTL listing, all you or the inspector should be concerned about is the MCA and Max OCP per 440.22(C)
Click to expand...
Is listing all that is necessary to verify integrated overload protection?
 
Your inspector is confused. The overload is internal to the unit. Your breaker is to protect your wire from a dead short or locked up compreser. The unit tells you min circuit amps to select wire and breaker size to comply with code. If you met this your legal. I always use the highest breaker size allowed by name plate. That saves you service calls for tripped breaker.
 
I agree with the guys above.
Your name plate would allow you to use #12 wire protected by a 40 amp breaker. Tell your inspector. The overload protection is built in to the unit.

You must use an HCAR breaker type.
 
Smart $ said:
Is listing all that is necessary to verify integrated overload protection?
Click to expand...

Wouldn't that depend on what the criteria is for receiving the listing?

I don't know what listing requirements are but have never seen a combination condenser/compressor unit that does not have overload protection installed as part of the unit. Stand alone compressor or condenser you see all kinds of things, especially on older units.
 
kwired said:
Wouldn't that depend on what the criteria is for receiving the listing?

I don't know what listing requirements are but have never seen a combination condenser/compressor unit that does not have overload protection installed as part of the unit. Stand alone compressor or condenser you see all kinds of things, especially on older units.
Click to expand...

Agree.
In my post (#2), I may assume too much with the listing, but, as you state, I have never seen combination compressor/condenser which did not have overload protection and they have all been listed and show MCA and Max OCP.
In the big ole world out there, some may exists that don't have O.L., but, my point is, I think most inspectors, once they see a listing with those requirements met, are satisfied.
 
augie47 said:
Agree.
In my post (#2), I may assume too much with the listing, but, as you state, I have never seen combination compressor/condenser which did not have overload protection and they have all been listed and show MCA and Max OCP.
In the big ole world out there, some may exists that don't have O.L., but, my point is, I think most inspectors, once they see a listing with those requirements met, are satisfied.
Click to expand...

I think that this is a time when you can assume. :)
 
Mgraw said:
I agree. I have not come across a hermetic A/C compressor without an internal overload.
Click to expand...
I can accept the assumption as well myself... but why not the inspector in the OP case? I realize we cannot answer this question, and thus the reason I gave the avenues of verification in my first post here.
 
Smart $ said:
I can accept the assumption as well myself... but why not the inspector in the OP case? I realize we cannot answer this question, and thus the reason I gave the avenues of verification in my first post here.
Click to expand...

Even inspectors have learning curves.
One reason most of us are here.
 
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