A C unit

[shadow]

I'm replacing a 2 ton A C unit with a 3 ton unit . I'm going to use what is already there. 30 amp. double pole breaker with no. 10 wire . Haven done residantial in a wile bit rusty. I think i can want to make sure. thanks./

 

[Dennis Alwon]

I'm replacing a 2 ton A C unit with a 3 ton unit . I'm going to use what is already there. 30 amp. double pole breaker with no. 10 wire . Haven done residantial in a wile bit rusty. I think i can want to make sure. thanks./

It depends on the unit. You need to know the nameplate MCA to answer the question.

 

[peter d]

You need size the over current protection based on the nameplate, not the size of the unit.

If the unit calls for a maximum HACR breaker of fuse size of 20 or 25 amps, then you will have to remove the 30 and replace it.

 

[220/221]

A 30 amp circuit is good for every new 3 ton unit I have ever seen.

 

[Minuteman]

A 30 amp circuit is good for every new 3 ton unit I have ever seen.

I've posted this before, but the rule-of-thumb for single phase A/C units that I was taught, is 10 amps per ton. Higher SEER units may be less, but it's as good of a guesstimate that you will need.