Failed inspection

[RICHRICH36]

Hello. I ran a circuit to a mini split condenser. I believe I am being hung out to dry because I am not in this "good ol boy network"

I failed for the following reasons.

No disconnect at the air handler. Keep in mind this is a mini split that obtains its power from the condenser (which has disconnecting means). I asked the inspector sarcastically, should I install a 60 amp pull out at each of these air handlers (there is 3) in the bedrooms and he said that would work perfectly fine.

I also failed my inspection and was written up for the AC contractors running their interconnect between the condenser and AHU's. The inspector stated that because the AHU is line voltage that it has to be done by the EC.

I attached a picture of the laundry list of the articles cited.

My question, is it out of the AC contractors scope to run the connection between the units and who has ever had to put a disconnect on a AHU of a mini split system that obtains its power from the condensor.

 

[augie47]

As far as the disconnect, many inspectors feel its required by 430.102.
It was discussed in this recent thread:
http://forums.mikeholt.com/showthread.php?t=173351&highlight=minisplit

As far as what license is required to install the cable, that is a local jurisdiction issue and not a NEC issue.

as far as the other items I don't see the attachment

 

[luckylerado]

...who has ever had to put a disconnect on a AHU of a mini split system that obtains its power from the condensor.

This is common practice. I prefer cord and plug or snap switches. I consider line voltage to be out of the AC guys scope. I am sure there are many that would be capable and many that are not.

 

[RICHRICH36]

Sounds like the consensus will be that this is common. I guess I will just roll with it and take care of it.

 

[GoldDigger]

Note that rather than a relatively obnoxious pullout you could use a snap switch if you can find one large enough.

(Smaller than the whole unit amperage, but must be HP rated to the fan motor.)

 

[mgookin]

Hello...

I attached a picture of the laundry list of the articles cited.

...

Your attachment did not carry through.

Hello...). I asked the inspector sarcastically, should I install a 60 amp pull out at each of these air handlers (there is 3) in the bedrooms and he said that would work perfectly fine.

...

That's already been addressed.

Hello. ..

My question, is it out of the AC contractors scope to run the connection between the units and who has ever had to put a disconnect on a AHU of a mini split system that obtains its power from the condensor.

Yes. It requires a EC license in Florida to run that wiring.


Nobody's out to get you. Those mini-splits have created a whole new wave of code compliance confusion. It seems to be getting worked out. Hang in there.

 

[kwired]

Note that rather than a relatively obnoxious pullout you could use a snap switch if you can find one large enough.

(Smaller than the whole unit amperage, but must be HP rated to the fan motor.)

Fan motors in those units are usually small enough they don't require HP rating on the switch. Have to look to know for certain but seem to recall 1/8 HP or less doesn't need HP rated switch, and or with general use snap switches the amp rating of switch can be a certain percentage over the motor rating and it still doesn't need HP rating. Seems like about 2 HP and below (at 240 volts) will generally allow a snap switch without much issues from what I can recall.

 

[RICHRICH36]

Fan motors in those units are usually small enough they don't require HP rating on the switch. Have to look to know for certain but seem to recall 1/8 HP or less doesn't need HP rated switch, and or with general use snap switches the amp rating of switch can be a certain percentage over the motor rating and it still doesn't need HP rating. Seems like about 2 HP and below (at 240 volts) will generally allow a snap switch without much issues from what I can recall.

Thank you, I maybe I became lackadaisical with the leniency in my home town. We have never had to run the connection between the AHU and CU.

 

[steve66]

As far as the disconnect, many inspectors feel its required by 430.102.
It was discussed in this recent thread:
http://forums.mikeholt.com/showthread.php?t=173351&highlight=minisplit

Maybe this was already brought up ( I didn't read all 3 pages), but I would interpret 440.8 as indicating a disconnect switch is NOT required at the indoor equipment.

 

[iwire]

IMO 440.8 does not change the requirement for an indoor disconnect.

 

[steve66]

IMO 440.8 does not change the requirement for an indoor disconnect.

Sorry if you have already explained this elsewhere, but care to elaborate on why? It sounds pretty cut and dry:

440.8 says an AC system may be considered a single machine. It refers to the system, not a single piece of equipment. Therefore, the evaporator/fans and condenser are all considered part of a single machine. They even clarify that "the motors shall be permitted to be located remotely from each other."

If that isn't enough, it specifically refers back to 430.112 Exception, which is all about a single disconnecting means being permitted to serve a group of motors.

 

[kwired]

Sorry if you have already explained this elsewhere, but care to elaborate on why? It sounds pretty cut and dry:

440.8 says an AC system may be considered a single machine. It refers to the system, not a single piece of equipment. Therefore, the evaporator/fans and condenser are all considered part of a single machine. They even clarify that "the motors shall be permitted to be located remotely from each other."

If that isn't enough, it specifically refers back to 430.112 Exception, which is all about a single disconnecting means being permitted to serve a group of motors.

I was considering replying and saying that the indoor unit doesn't fall under 440, but first I read 440.1 and since these mini split units typically have both indoor and outdoor unit on same branch circuit I think it does. I don't believe the indoor unit of most typical central units however is covered by 440 mostly because it is on a different circuit and does not have a compressor.

 

[iwire]

Sorry if you have already explained this elsewhere, but care to elaborate on why? It sounds pretty cut and dry:

440.8 says an AC system may be considered a single machine. It refers to the system, not a single piece of equipment. Therefore, the evaporator/fans and condenser are all considered part of a single machine. They even clarify that "the motors shall be permitted to be located remotely from each other."

If that isn't enough, it specifically refers back to 430.112 Exception, which is all about a single disconnecting means being permitted to serve a group of motors.

What section of the NEC tells us motors located remotely of the same machine do not require a disconnecting means?

 

[wwhitney]

What section of the NEC tells us motors located remotely of the same machine do not require a disconnecting means?

430.112 Exception, as steve66 cited.

Cheers, Wayne

 

[wwhitney]

Here you go:

440.8 Single Machine. An air-conditioning or refrigerating system shall be considered to be a single machine under the provisions of 430.87, Exception, and 430.112, Exception. The motors shall be permitted to be located remotely from each other.

and

430.112 Motors Served by Single Disconnecting Means. Each motor shall be provided with an individual disconnecting means.

Exception: A single disconnecting means shall be permitted to serve a group of motors under any one of the conditions of (a), (b), and (c). The single disconnecting means shall be rated in accordance with 430.110(C).

(a) Where a number of motors drive several parts of a single machine or piece of apparatus, such as metal- and woodworking machines, cranes, and hoists.

Cheers, Wayne

 

[iwire]

430.112 Exception, as steve66 cited.

Cheers, Wayne

I will put some more thought into this thanks

Still stuck with 110.3(B) and the instructions.

 

[wwhitney]

Still stuck with 110.3(B) and the instructions.

Yeah, if the instructions call for a disconnect, then I think you are stuck with one. But that disconnect only has to meet the instruction's specifications, not the NEC usual motor disconnecting means specifications.

Cheers, Wayne

 

[iwire]

Yeah, if the instructions call for a disconnect, then I think you are stuck with one.

I agree.

But that disconnect only has to meet the instruction's specifications, not the NEC usual motor disconnecting means specifications.

I am not willing to agree to that yet and I highly doubt I would pass inspection in my area without them.

 

[steve66]

I also agree its a mute point if the instructions require a disconnect.

I can't figure out what other purpose 440.8 could serve other than allowing a single disconnect for something like a split system. However, when I look at 440.14 - "Disconnecting means shall be located within sight from and readily accessible from the AC or Refrig. equipment...", it doesn't seem to allow one disconnect to serve multiple pieces of equipment if they are remotely located.

I can't figure out what the intent was.

 

[iwire]

I also agree its a mute point if the instructions require a disconnect.

I can't figure out what other purpose 440.8 could serve other than allowing a single disconnect for something like a split system. However, when I look at 440.14 - "Disconnecting means shall be located within sight from and readily accessible from the AC or Refrig. equipment...", it doesn't seem to allow one disconnect to serve multiple pieces of equipment if they are remotely located.

I can't figure out what the intent was.

Just thinking out loud here but it seems that one of the problems with how the NEC is modified, a section or exception at a time by various people and CMPs results in quandaries such as this one.