Why would I need a minimum?

[Willie Snyder]

We are having a debate as part of the myth of the week, why does the manufacturer post a minimum on their nameplate since there is no minimum as long as the A/C starts?

 

[LarryFine]

MCA? Because the circuit must be able to supply the running load without overheating.

It's the OCP that allows for starting current, not the MCA.

Maybe I don't understand the question.

 

[electrofelon]

I would say just another label with confusing/incorrect/superfluous/dumb information on it. The HVAC industry has to put one of these on every 17th unit, it seems.

 

[ActionDave]

A preemptive strike against electricians who don't understand how to size circuits for A/C units and put too small a breaker on the circuit and the manufacturer has to deal with warrantee headaches.

 

[ptonsparky]

Aren't all breakers now HACR?

 

[tom baker]

To keep the GFCI from tripping.

 

[ptonsparky]

To keep the GFCI from tripping.

Breaker ampacity would have nothing to do with GFCI function.

 

[jim dungar]

Aren't all breakers now HACR?

Yes, for some 30 years now.

 

[Willie Snyder]

To keep the GFCI from tripping.

GFCI is not required

 

[Dennis Alwon]

We are having a debate as part of the myth of the week, why does the manufacturer post a minimum on their nameplate since there is no minimum as long as the A/C starts?

The manufacturers minimum circuit ampacity used to be based on the NEC that states we must go 125% of the unit FLA.

 

[ptonsparky]

The manufacturers minimum circuit ampacity used to be based on the NEC that states we must go 125% of the unit FLA.

As I see it, without the stickers shown, I can use whatever BC protection, >or= to MCA, I want as long as it does not exceed the MOP. NEC does require the unit to start with that protection.