Red tag on mini-split control cable

Status
Not open for further replies.
Coppersmith

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
An inspector rejected an installation of a mini-split a/c system because the control cable between the compressor and the head was not in a raceway. He sited 326.16 (which doesn't exist in 2014) and said it wasn't in a raceway. He probably meant 336.12(2). The part that is exposed is about three feet before it goes into a "trough" (not an electrical trough) along with the refrigerate lines. It's zip-tied to the lines. This is the standard installation and has never been flagged by an inspector before.

Q1: Is that cable a type TC? (It's four conductor, low voltage, doesn't seem to be marked.)

Q2: Would sleeving it in liquidtite until it gets inside the trough sufficient? Or does it need to be in a raceway all the way to the head unit?
 
Coppersmith said:
An inspector rejected an installation of a mini-split a/c system because the control cable between the compressor and the head was not in a raceway. He sited 326.16 (which doesn't exist in 2014) and said it wasn't in a raceway. He probably meant 336.12(2). The part that is exposed is about three feet before it goes into a "trough" (not an electrical trough) along with the refrigerate lines. It's zip-tied to the lines. This is the standard installation and has never been flagged by an inspector before.

Q1: Is that cable a type TC? (It's four conductor, low voltage, doesn't seem to be marked.)

Q2: Would sleeving it in liquidtite until it gets inside the trough sufficient? Or does it need to be in a raceway all the way to the head unit?
Click to expand...

You will get flagged in Maine for the tray cable. 14/4 UF is what everyone is using. TC was being used until all the inspectors got together and said it wasn't listed for that application
 
wallyworld said:
You will get flagged in Maine for the tray cable. 14/4 UF is what everyone is using. TC was being used until all the inspectors got together and said it wasn't listed for that application
Click to expand...

Are you on the '17 code yet? TC-ER cable is now allowed in residential applications.


SceneryDriver
 
wallyworld said:
You will get flagged in Maine for the tray cable. 14/4 UF is what everyone is using. TC was being used until all the inspectors got together and said it wasn't listed for that application
Click to expand...

It's what comes with the unit as far as I know. (I don't install the units. I install the circuit for the units)
 
Coppersmith said:
It's what comes with the unit as far as I know. (I don't install the units. I install the circuit for the units)
Click to expand...

I think that's why the '17 code finally did away with the TC cable being disallowed in residential nonsense.

Mini-splits are becoming more and more popular, and it was a mess with the units being NTRL listed (and having to follow the install instructions to remain so) conflicting with the NEC's TC prohibition.

It was once explained to me (maybe here on the forum) that TC manufacturers were reluctant to get TC approved for residential because they also made NM and SE cables, and didn't want to cannibalize their own sales markets.

I think it was ridiculous - it's a completely different use case than other cable types, though I'd love to see someone wire an entire house with it. We just finished a job where our techs installed almost a mile of it in a venue on the top deck of a cruise ship (outdoors), and the stuff is near bomb-proof. Easy to work with too, unless it's really cold.


SceneryDriver
 
SceneryDriver said:
Are you on the '17 code yet? TC-ER cable is now allowed in residential applications.


SceneryDriver
Click to expand...

Be careful. Its not a blanket acceptance. There are conditions including special marking ("JP" ikf I recall correctly.. and I've not seen any so marked)

SceneryDriver said:
I think that's why the '17 code finally did away with the TC cable being disallowed in residential nonsense.

Mini-splits are becoming more and more popular, and it was a mess with the units being NTRL listed (and having to follow the install instructions to remain so) conflicting with the NEC's TC prohibition.

It was once explained to me (maybe here on the forum) that TC manufacturers were reluctant to get TC approved for residential because they also made NM and SE cables, and didn't want to cannibalize their own sales markets.

I think it was ridiculous - it's a completely different use case than other cable types, though I'd love to see someone wire an entire house with it. We just finished a job where our techs installed almost a mile of it in a venue on the top deck of a cruise ship (outdoors), and the stuff is near bomb-proof. Easy to work with too, unless it's really cold.


SceneryDriver
Click to expand...
I believe the generator folks pushed the acceptance bu it is applicable for mini-splits.
 
augie47 said:
Be careful. Its not a blanket acceptance. There are conditions including special marking ("JP" ikf I recall correctly.. and I've not seen any so marked)


I believe the generator folks pushed the acceptance bu it is applicable for mini-splits.
Click to expand...

The "JP" is in an informational note, so I don't think it's enforceable.

336.10 (9) states that it must be marked TC-ER for "tray cable - exposed run" to be used in one- and two-family dwelling units. ER means that it meets the same crush resistance requirements as MC cable, among others.

It also states that TC must be installed per the requirements of 334, Part II - nonmetallic sheathed cables. It can be installed just like Romex now.

I'm ready to stand corrected though; I know the code doesn't always mean what I think it says. :)



SceneryDriver


SceneryDriver
 
Type CVVS control cable

Type CVVS control cable

I've got a project that is using LG mini splits and the mechanical contractor did not install his control cable. We've wired hundreds of these in SoCal and this is the first time the HVAC guys have not installed the factory supplied control cable. LG calls for a 12-4 CVVS cable. From what I can see this is a designation used in Asian countries and I am not sure how it translates to US standards. I've always wondered how they could run a cord set in walls, but I've only seen one project turned down when the HVAC guys used an SO cord. I would like to avoid any issues. The LG indoor unit is 230V and draws .8 amps.
 
Why do those manufacturers send tray cable with their units? This has caused more trouble than anything. They should read the code. Fortunately, the 2017 has made it compliant in residences if marked.

The cable looks like ser cable. Not sure why it is a big issue.
 
What about baby bx we use it here to wire thermostats sometimes basically it's comes in a variety of sizes 18/16/14 in ac cable

Sent from my SM-G950U using Tapatalk
 
nickelec said:
What about baby bx we use it here to wire thermostats sometimes basically it's comes in a variety of sizes 18/16/14 in ac cable

Sent from my SM-G950U using Tapatalk
Click to expand...

If it's actually a "BX" (Type AC) cable then 320.12 would not permit it in a wet or damp location.
For a while folks here were using a Jacket MC cable but the listed connectors are pretty expensive.
UF is becoming the install wire of choice.
 
You can treat it like a feed for the condenser, mount s box on the outside and poke into the back

Sent from my SM-G950U using Tapatalk
 
Coppersmith said:
An inspector rejected an installation of a mini-split a/c system because the control cable between the compressor and the head was not in a raceway. He sited 326.16 (which doesn't exist in 2014) and said it wasn't in a raceway. He probably meant 336.12(2). The part that is exposed is about three feet before it goes into a "trough" (not an electrical trough) along with the refrigerate lines. It's zip-tied to the lines. This is the standard installation and has never been flagged by an inspector before.

Q1: Is that cable a type TC? (It's four conductor, low voltage, doesn't seem to be marked.)

Q2: Would sleeving it in liquidtite until it gets inside the trough sufficient? Or does it need to be in a raceway all the way to the head unit?
Click to expand...

In the last two years or so we have gotten into doing a couple of our own ductless installs. When I first started I used 14-3UF as my signal cable, but we do hookups for a number of HVAC companies and I saw they were using the tray cable, since then I’ve been using a #14-4 TC-ER cable from Southwire. I had my inspector tag it for the same thing (I zip tied it to the line set), I don’t recall the Code reference he used but to fix it I sleeved it in non-metallic liquidtight from the about 1ft into the “trough” (I believe the guys out our way, on the HVAC side, call it “line-hide”) and then all of the exposed cable to the compressor. He signed off on it and I have been doing it that way ever since.

E42AF69F-DFFE-4A6D-BF13-9F38974C3ACE.jpg

ETA: the picture is so small it’s worthless the cable jacket reads- SOUTHWIRE F (UL) 14 4 CDRS TYPE TC-ER THHN OR THHW CDRS 90* JACKET SUNLIGHT RESISTANT DIRECT BURIAL 600V
 
Last edited:
Mini Split Types

Mini Split Types

There are some units that are control voltage between the indoor and outdoor unit, but most I have installeld are line voltage with the indoor unit configured as " slave " to the outdoor and the total system is fed from one breaker.
 
Status
Not open for further replies.
Top