Mini-Split Disconnect??

[augie47]

I've always thought as iwire that a disconnect is required at the indoor fan/coil unit of a mini-split. But david's comment back in post #27 that 422.31(A) would apply in most of the smaller units seems to be correct. What say all?

I've been jousting with this windmill for so long I fear I've forgotten some of the
details, but I want to say when that was brought into the discussion there was a problem with the listing on the unit being other than an "appliance" but that route may be worth re-investigating.

As far as the factory cables often not being compliant with NEC, what have we come to as far as NRTL value? This has been an issue since these units came to market. Why don't the NRTLs care? And the instructions that typically come with these units are an insult!

My experience has been that I have received very little input from ETL beyond "we are looking into that" and UL advises they only provide the "Standard" to which ETL refers. It appears to be a ball that no one wishes to carry.

Listings are what they are, but it staggers me a little to think that TC cable can't be used without a raceway in residential settings. I just finished a job with TC cable; it's like NM, but with a jacket on steroids. It's certainly no more fragile than NM; I'd say it's actually much tougher. There seems to me to no reason, other than vendor paperwork, that TC couldn't be used anywhere NM can.
SceneryDriver

I agree that it should be acceptable based on the properties you note.
That said, from an inspectors stand point is that it remains a violation awaiting change in the Code or the listing of the cable.
If there was a failure of some type the inspector allowing such an install is standing on poor ground as long as it's a violation.

 

[jahilliard]

Just to be clear...as the OP, I mostly agree with the need for the disconnect, it makes logical sense really. But bringing up the question and creating a conversation has enhanced my understanding of why/why not? vastly! I love the 422.31(A) argument from the one of the last posts..hmm. It can become confusing when inspectors can vary so greatly on the same circumstance...and when you're trying to bid projects, answer to owners that are more concerned with appearance than safety, and employees that want to do as little as possible and blame everyone else for having to go back...it's really nice to have a solid reference and understanding which in turn allows you to make better decisions in the future and create a solid standard regardless of the potential variables. Not to mention, I want inspectors to be put on the spot on occasion and for them to be able to respond in a manner most can understand...and that sometimes takes more than one "code" reference and sometimes a little practical application as well. I can only imagine the grief inspectors have to go through on a daily basis...but these conversations are priceless..coming up in the trade as an apprentice I learned more from these conversations as a whole than most anything else. Thanks to all.

 

[david luchini]

but I want to say when that was brought into the discussion there was a problem with the listing on the unit being other than an "appliance" but that route may be worth re-investigating.

I don't see anything in the definition of appliance that says it must be "listed" as appliance.

I wonder if the units with instructions that show a disconnect, such as Bob referenced in post #11, are rated greater than 300va. That would be interesting to look at.

 

[augie47]

I don't see anything in the definition of appliance that says it must be "listed" as appliance.

I wonder if the units with instructions that show a disconnect, such as Bob referenced in post #11, are rated greater than 300va. That would be interesting to look at.

To me it adds to the confusion, your post references 422.31 and Art 422 notes it does not apply to Art 440 (except as ammended). During my discussions with the NRTL there was discrepency as to these units meeting UL1995 Heating & Cooling equipmet or UL484 Room Air Conditioners. Most seem to comply with UL1995, split systems so an argument could be made that Art 422 is not applicable.... the suggestion is certainly not without merit, IMO.

 

[david luchini]

To me it adds to the confusion, your post references 422.31 and Art 422 notes it does not apply to Art 440 (except as ammended).

I think you are reading this wrong. I don't see anything that says Art 422 does not apply to Art 440 installations.

422.1 says that Art 422 covers electrical appliances used in any occupancy.

422.3 says that Article 430 shall apply to the installation of motor-operated appliances, and Article 440 shall apply to the installations of appliances containing a hermetic refrigerant motor-compressor, EXCEPT as specifically amended in Art 422. Section 422.31 includes specific amendments to disconnecting means requirements for appliances with certain ratings.

(In addition, I don't see how Art 440 would apply to the indoor unit. It includes only a fan, not a compressor. It would be a Art 430 and Art 422 installation.)

 

[augie47]

Does this not appear in the '14 Code ?
422.3 Other Articles.

The requirements of Article 430 shall apply to the installation of motor-operated appliances,and the requirements of Article 440 shall apply to the in-stallation of appliances containing a hermetic refrigerant motor-compressor(s), except as specifically amended in this article

(I only have a daft copy.. I was basing my answer on '08)
Since the UL standard for these units (all components) referenced split Air Conditioning units my opinion is that this is an Art 440 item.
It is MY OPINION. You are welcome to yours and as I quick to say it has merit.
It is not my intent to enter into a spitting contest .... I just happen to think it is not an Art 422 issue. I've not looked at the motor size so it might be a mute point anyway,
The entire issue needs a lot of help from Listing agencies, Code folks, manufacturers, etc. It is a mess and there are too many ways to address it.

 

[david luchini]

Does this not appear in the '14 Code ?
422.3 Other Articles.

The requirements of Article 430 shall apply to the installation of motor-operated appliances,and the requirements of Article 440 shall apply to the in-stallation of appliances containing a hermetic refrigerant motor-compressor(s), except as specifically amended in this article

As far as I know, that still exists in the 2014 Code. I was reading the 2011, but it says the same thing. You would apply 422 to ALL appliances. You would apply 430 to a motor-operated appliance, and you would apply 440 to a hermetic refrigerant motor-compressor containing appliance, AND you would apply any specific provisions in 422 that amend the requirements of 430 or 440 to motor-operated, compressor containing appliances. Applying 430 or 440 doesn't preclude the use of 422...the should be applied together.

Since the UL standard for these units (all components) referenced split Air Conditioning units my opinion is that this is an Art 440 item.
It is MY OPINION. You are welcome to yours and as I quick to say it has merit.
It is not my intent to enter into a spitting contest .... I just happen to think it is not an Art 422 issue. I've not looked at the motor size so it might be a mute point anyway,
The entire issue needs a lot of help from Listing agencies, Code folks, manufacturers, etc. It is a mess and there are too many ways to address it.

I always value your opinion. I'm just reading the Code in the simplest terms and don't think that the UL standards have a bearing on this.

I've noticed that no one addressed the issue that the conductors from the outdoor unit to the indoor unit wouldn't be branch circuit or feeder conductors. Do you have any opinions on whether that would affect disconnecting requirements?

 

[mikeadams2]

In Massachusetts, there is an actual Massachusetts Amendment to the NEC that states,

"440.14. Insert a third informational note as follows:

Informational Note No. 3: See 440.3(B) for general provisions regarding the inapplicability of Article 440 to equipment that does not incorporate hermetic refrigerant motor-compressors. See also 430.109(B) for specific provisions governing the disconnecting requirements for such equipment, wherever located, that uses a motor that is 1/8 hp or less."

When you then go to 430.109(B), it states that the branch-overcurrent device may be used as the disconnecting means (as long as it's 1/8 HP or less).

 

[GoldDigger]

Thank you for the update, but I am closing this 6 year old thread.

 

[tom baker]

I can show you many instructions that show one.

But regardless the NEC requires one baring local amendments. Its a motor.

As far as looks not the NECs concern but we use a wall switch beside the unit in a color to match other devices

Every motor requires a disconnect, even the exhaust fan in a bathroom.