HVAC Disconnect or Circuit Breaker..What is it?

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GrayHeadedMule

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I am having a discussion (his voice got louder as we discussed) with one of my inspectors about disconnects at the outside condensing unit.

I am saying that the switch type of disconnects do not protect the equipment because the apparatus is a "switch" and not a circuit breaker. He is saying it's a breaker. Is there such animal? I have heard there was. Or am I way out in left field on this one?

We see this a lot on AC change-outs because the newer units do not require as large of a breaker as they have in the past. A 30 Amp breaker may be the maximum allowed on a new unit and a 40 or 50 amp breaker is still installed in the panel box. They install a 30 amp switch and say "It's protected because of the 30 amo rating". I say "No...it's just a switch and does not offer any protection at all".

I have heard that they do make a disconnect that actually has a breaker as the disconnect. Isn't there something out there about having two breakers on the same circuit or is this good?

Comments????
 
There are A/C disconnects that consist of a molded case switch that looks like a molded case circuit breaker but do not provide overcurrent protection. Square D is one manufacture that makes these type of A/C disconnects.

I have heard that they do make a disconnect that actually has a breaker as the disconnect. Isn't there something out there about having two breakers on the same circuit or is this good?
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You could use a circuit breaker enclosure with a molded case circuit breaker as a disconnecting means for an A/C unit.

Chris
 
Yes, the make an A/C disconnect that is nothing more than a switch. Generally they are not used here because they are double or more the price of regular pull-out disconnect.
 
If the new unit had a Maximum OCPD size of 30 amps listed on the nameplate then you would need an OCPD that was 30 amps or less. A 30 amp switch on a 40 amp circuit cannot serve as an OCPD.
 
Thanks for the replies.

Do they make a disconnect that is actually a breaker?

You would think that this type of disconnect would be more costly than a switch type since the switch type are almost double of the pull-out type!
 
With today's a/c units a disconnect is all that is needed. There is no need for OCPD at the unit. It would not hurt anything to have OCPD at the unit it just is not required unless the unit says max fuse only. Just change the breaker at the panel.
 
GrayHeadedMule said:
Thanks for the replies.

Do they make a disconnect that is actually a breaker?

You would think that this type of disconnect would be more costly than a switch type since the switch type are almost double of the pull-out type!
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They make a wp enclosure that you could install one breaker in.
 
Dennis Alwon said:
With today's a/c units a disconnect is all that is needed. There is no need for OCPD at the unit. It would not hurt anything to have OCPD at the unit it just is not required unless the unit says max fuse only. Just change the breaker at the panel.
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I hope that NM cable isn't involved. ;) :grin:
 
Dennis Alwon said:
With today's a/c units a disconnect is all that is needed. There is no need for OCPD at the unit.
Click to expand...

There would be a need in the OPs case.

A 30 Amp breaker may be the maximum allowed on a new unit and a 40 or 50 amp breaker is still installed in the panel box. They install a 30 amp switch and say "It's protected because of the 30 amo rating"
Click to expand...

Apparently they do not want to change the breaker inside.
 
GrayHeadedMule said:
We see this a lot on AC change-outs because the newer units do not require as large of a breaker as they have in the past. A 30 Amp breaker may be the maximum allowed on a new unit and a 40 or 50 amp breaker is still installed in the panel box. They install a 30 amp switch and say "It's protected because of the 30 amo rating". I say "No...it's just a switch and does not offer any protection at all".
Click to expand...

I think this will continue to remain a problem with all the change outs to high efficiency equipment.
 
Thanks again. I appreciate the information.

I think it would cost a little more to install a wp box and then purchase a breaker to fit than just leaving the existing disconnect and change out the breaker.

He (the other inspector) says they sell them (circuit breaker disconnect) at Lowes. I asked... You sure it's not just a switch?
 
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