Resi AC compressor fuse or not to fuse?

[mltech]

When can you use a nonfused disconnect for a residential AC compressor? Millbank is making a combination no fuse disconnect and GFI in a 3R configuration. I would like to use these as they would save in labor but unsure on the fusing of the compressor. If the compressor nameplate says max fuse or Brkr would the panel brkr be sufficient?

 

[roger]

Re: Resi AC compressor fuse or not to fuse?

Yes, the over current protection can be in the panel. The millbank unit would be fine for the local disconnecting means.

Roger

 

[renosteinke]

Re: Resi AC compressor fuse or not to fuse?

I disagree. The answer is found on the equipment.
If the lable says "max. FUSE...." then a fuse must be in the circuit somewhere- a circuit breaker alone is not sufficient protection.
Fuses respond quicker than circuit breakers, and are available in a wider range of sizes.
If the circuit originated in a breaker panel, the disconnect is a convenient place for the fuses to be- but they have to be somewhere.

 

[iwire]

Re: Resi AC compressor fuse or not to fuse?

Yes that is true, but read the last sentence of the question.

 

[roger]

Re: Resi AC compressor fuse or not to fuse?

Reno, no argument about the fuses, and I didn't say breaker, I said "overcurrent protection.

There are still existing fuse distributon panels.

Roger

 

[ryan_618]

Re: Resi AC compressor fuse or not to fuse?

If the breaker is the only overcurrent protection, I believe the breakers have to have some sort of rating, but I can't remember what it is. Can someone help me there? I beleieve it is a series of 4 letters.

 

[iwire]

Re: Resi AC compressor fuse or not to fuse?

HACR Breakers.

And the same applies for them as the fuses.

If the unit label does not specify HACR breakers or Fuses we are free to use any breaker or fuse that meets the listed ampacity.

[ October 14, 2003, 08:40 PM: Message edited by: iwire ]

 

[roger]

Re: Resi AC compressor fuse or not to fuse?

I thought it was HACR, oh well.

Roger

 

[iwire]

Re: Resi AC compressor fuse or not to fuse?

Originally posted by roger:
I thought it was HACR, oh well.

Roger

It is, I goofed, fixed it now.

 

[ryan_618]

Re: Resi AC compressor fuse or not to fuse?

Thanks guys, that was driving me crazy trying to remember it.

 

[hbiss]

Re: Resi AC compressor fuse or not to fuse?

Easy to remember. You are using the breaker or fuse to supply one of these- Heating, Air Conditioning, Refrigeration.

 

[ryan_618]

Re: Resi AC compressor fuse or not to fuse?

Wouldn't HVAC be easier? I mean, one less acronymn to remember. In all seriousness, thanks a lot, that will certainly help!

 

[hillbilly]

Re: Resi AC compressor fuse or not to fuse?

If the label say's Max Fuse OR HACR breaker rating, OR is the key word is it not. I don't see where fuses are required if the non-fused disconnect is fed from a properly sized HACR breaker. Please tell me if I'm wrong.
steve

 

[roger]

Re: Resi AC compressor fuse or not to fuse?

Steve, in the past and maybe even now, (although I haven't personaly seen it for quite awhile) some manufacturers stated "MAX FUSE" and would not warranty their equipment if protected by a breaker. Then as the HACR breakers became more common the wording "MAX FUSE or HACR BREAKER became the norm.

Roger