40 Amp Breaker Supplies Big Unit

[randynavarro]

Nameplate on the condenser spec'd a max 50 amp fuse.

Feeder was 40 amp.

Is this a problem?

May the breaker just trip more frequently?

[hausdok]

Hi Randy,

I think that if it's holding up and not tripping at 40 amps that it's just fine. It probably won't trip at all when the system is working fine, but it might begin tripping as the unit gets older and more worn and draws current above 40 but still less than 50 amps upon startup. If the feeder is only rated for 40 amps that could be a problem, when/if that occurs.

Now, try and remember that, like you, air conditioners are, for me, like little green men. Expect Jim or someone from an area where they are common to come on here and straighten me out most rikki tick.

ONE TEAM - ONE FIGHT!!

Mike

[Bill Kibbel]

Originally posted by randynavarro

Nameplate on the condenser spec'd a max 50 amp fuse.

Feeder was 40 amp.

Is this a problem?

May the breaker just trip more frequently?

Most data plates list min. amp fuse/breaker as well.

[randynavarro]

Bill, yes, the min. was 30 amp.

What's your point?

[Phillip]

Randy,

The min is the smallest the breaker can be and the max. is the largest the breaker can be so the 40 amp would be all right.

[randynavarro]

Originally posted by Phillip

Randy,

The min is the smallest the breaker can be and the max. is the largest the breaker can be so the 40 amp would be all right.

Understand.

I guess I wasn't clear on my question.

Is a 40 amp breaker undersized give the potential draw of the unit?

[Phillip]

Randy what was the running amps on the data tag and the size of the wire?

[randynavarro]

Originally posted by Phillip

Randy what was the running amps on the data tag

Dont have it in front of me (I'm out in the field right now), but I recall somewhere in the low 20's?

and the size of the wire?

No. 8 copper

[Bill Kibbel]

Originally posted by randynavarro

Bill, yes, the min. was 30 amp.

What's your point?

You asked if having a smaller feeder than the max fuse specified was a problem. I guess my point was that it shouldn't be a problem , unless it was less than the min fuse size listed.

[Terence McCann]

Originally posted by randynavarro

Nameplate on the condenser spec'd a max 50 amp fuse.

Feeder was 40 amp.

Is this a problem?

May the breaker just trip more frequently?

Randy, put this one in the live box, it's a good write up regarding "Using MCA and MOP Ratings to Safely Connect Your Field Wired Air Conditioner"

http://www.apcmedia.com/salestools/KSIH ... _R0_EN.pdf