Help with first report

[waksell]

Inspected a condo today.
The condenser units data sticker says, "max fuse or ckt. bkr. 20 amps". The disconnect has a 60 amp 2 pole breaker installed in it. I noticed that the disconnect serves two condensers. How can this be right. I did not remove the cover of the disconnect box because there were mud dauber nests all over it.


The data sticker on the air handler says "max. current rating of supply circuit fuse or HACR type ckt. bkr. 30/25". The disconnect box had a 60 amp breaker in it.

Seems to me that both units are overfused. What say you?

[David P. Valley]

You are referring to the disconnect next to the condensers, right?

If you've got one 60 Amp breaker protecting two condensers, that's simply overfused and double tapped inside. Safety issue, big time.

And if the residential Air Handler is protected by a 60 Amp breaker also, you've got overfusing there too.

[waksell]

Thought so. Thanks.

[smcarthur]

Over fusing is very common on A/C units. For one the disconnects are sometimes installed by the HVAC installer, who is only concerned that the fuse doesn't blow, and two a lot of A/C units are replacements and the installer doesn't bother to check or change the disconnect.
Could you tell me, just out of curiosity, how you were able to tell the size of the breaker without opening the disconnect? If the breaker is in a weather proof enclosure the breaker shouldn't have been visible.

[Paul W. Abernathy]

Wesley,

I would say the feeding (2) outside units from a single disconnect leaves me saying have it evaluated...most certainly if we are only talking about a single 20A supply.

As for a general understanding, many times a disconnect at a outside unit or even inside unit will have 60A on it but are then protected back at the panel with a lets say 30A breaker ( for arguement sake )...the 60A breaker or disconnect at the unit would then simply be the service switch at the unit for disconnection means and not the overcurrent protection device...this would take place back at the panel....just in case anyone wanted to know about that.

[waksell]

Originally Posted by smcarthur

Over fusing is very common on A/C units. For one the disconnects are sometimes installed by the HVAC installer, who is only concerned that the fuse doesn't blow, and two a lot of A/C units are replacements and the installer doesn't bother to check or change the disconnect.
Could you tell me, just out of curiosity, how you were able to tell the size of the breaker without opening the disconnect? If the breaker is in a weather proof enclosure the breaker shouldn't have been visible.

I could open the lid but not remove the cover. Breaker or switch was inscribed 60.

Attachment 8748

[waksell]

Originally Posted by pabernathy

Wesley,

I would say the feeding (2) outside units from a single disconnect leaves me saying have it evaluated...most certainly if we are only talking about a single 20A supply.

As for a general understanding, many times a disconnect at a outside unit or even inside unit will have 60A on it but are then protected back at the panel with a lets say 30A breaker ( for arguement sake )...the 60A breaker or disconnect at the unit would then simply be the service switch at the unit for disconnection means and not the overcurrent protection device...this would take place back at the panel....just in case anyone wanted to know about that.

Paul, I would say that I was mistaken when I said that the disconnect served two units. I was so nervous on my first inspection that I was not thinking clear. The disconnect had two flexes coming out of the bottom, one to the unit in question, and another "toward another unit a few feet away". I assumed it was serving that unit. After my post I realized that the other flex was actually coming from out of the ground and providing power to, not from, the disconnect.

Attachment 8752
Attachment 8751

[David A. Andersen]

Normally I do not get too excited about circuit breakers that are larger than recommended by the equipment manufacturer as long as they are not excessively large.

The way I look at this issue is that the circuit breaker is there to protect the wiring from the breaker to the unit (or another subpanel).
Next, the issue that you may have found (if you had opened up the panel, which I feel you should have) is that the wire must be rated for the circuit breaker size. Depending on the type of wire, 60 amp conductor may be excessively large to be attached to the magnetic contactor (in most cases always is). So, this is reverse engineering to some extent. We have a unit that can handle 20 amp wire size. If the wire is properly sized for the 60 and breaker then it is oversized and will not attach properly to the unit and that is a problem.

If the wire is not properly sized for the 60 amp breaker than that is the issue.
Why didn't you open the panel? Mud wasps are not active in the wintertime anywhere. They are simply dormant nests. If you saw one circuit breaker and feel that there is two condensing unit's operating from that one disconnect, it should be obvious that a double tap is possible. Unless there is a swarm of bees actively staring you in the face I think I would have opened the panel.

I am not suggesting that you do not "report" be over amperage breaker.

[dchew]

Normally, my rule of thumb is that you want the weakest link in any electrical circuit to be the circuit breaker. It can't be undersized or oversized. You want it to trip at the right time to protect whatever the load is. The manufacturer's spec plate on the condensor should indicate what the recommended breakers size is.

That is why you also check wire size. If it's too thin, it over heats and becomes a fusible link. Not a good thing.

[brepanshek]

Congratulations on your 1st Inspection. Enjoy what your doing and the nerves should go away. Remeber your only human