Mini split - securing mc interconnect to line set

JGinIndy

Semi Retired EC,EI and Plan Review
Location
Indiana
Occupation
Retired Electrician currently County Inspector
This particular case it is the entire length of the line set, some runs may be around 60'. The line sets do not run through or in any plenums or fire rated assemblies.
Above Grid: Fire rated, Non Fire rated, Plenum or Non plenum.
So do we agree independent support ie. Separate grid wire with bat wing, zip tie or tie wire to joists or deck can be enforced? If you, mechanical and inspector agree to secure to line set then good to go. As we all agree it’s different from one ahj to next but I have always tried to stick to what the code says not let a personal preference be my guide.
Thanks and good conversation.
 

kwired

Electron manager
Location
NE Nebraska
That was the point of the entire conversation. Can one “zip tie” mini split / VRF transmission cable to and along the line set? I assumed above grid and some inspectors allow it, some don’t, some mechanical contractors say no, some say yes. Where I worked in D.C. No. where I am now just north of Indy No.
But you also mentioned "when the deck is a ways up". What difference does that make? You are supporting the same cable from the same line set either way.
 

JGinIndy

Semi Retired EC,EI and Plan Review
Location
Indiana
Occupation
Retired Electrician currently County Inspector
But you also mentioned "when the deck is a ways up". What difference does that make? You are supporting the same cable from the same line set either way.
Never said I would approve securing the MC to line set. What I meant is if the distance from grid to deck is a “ Ways up” then drop down an independent support wire shot to deck then attach to grid, flag it let’s say yellow for the heck of it then bat wing the MC. If it’s just a hugger grid to deck then just zip tie the MC to the building structure like the steel joists, etc.
 
So do we agree independent support ie. Separate grid wire with bat wing, zip tie or tie wire to joists or deck can be enforced? If you, mechanical and inspector agree to secure to line set then good to go. As we all agree it’s different from one ahj to next but I have always tried to stick to what the code says not let a personal preference be my guide.
Thanks and good conversation.
No I still am not seeing a requirement for "independent support". Support that is independent from the grid wires yes.
 

kwired

Electron manager
Location
NE Nebraska
Never said I would approve securing the MC to line set. What I meant is if the distance from grid to deck is a “ Ways up” then drop down an independent support wire shot to deck then attach to grid, flag it let’s say yellow for the heck of it then bat wing the MC. If it’s just a hugger grid to deck then just zip tie the MC to the building structure like the steel joists, etc.
Well if not tying to the line set, or other pipes, or system components then it is either do something like what you said or let it lay on the grid, or stretch it tight enough it won't sag enough to touch the grid.... I guess.

Isn't the question here about whether it is code compliant to support it from the line set? If your answer is no, what code are you going to cite? Other than what you already mentioned that others have disagreed with, pointing out it doesn't say what you want it to say.
 

lauraj

Senior Member
Location
Portland, Oregon
I don't see why not, as long as there is nothing in the sprinkler code not allowing it. If the NEC doesn't want us securing to other pipes and utilities, they should say so.
Yes you are correct, and yes sprinkler code does not allow it. I'm not familiar enough with other building codes to know if that would be where we find that.

For me, I wouldn't want the support of my conduits/cables to rely on another trade's installation since I have no idea what's going to happen with that other mechanical system in the future.
 

JGinIndy

Semi Retired EC,EI and Plan Review
Location
Indiana
Occupation
Retired Electrician currently County Inspector
NFPA13 9.1.1.7 does not permit supporting any foreign materials. As far as supporting to water piping. gas piping, etc IPC, IMC, IFGC are a little silent but just more of a trade to trade thing as being respectful to others equipment. I did take some time today and contacted a few of my IAEI colleagues to discuss securing MC cable above grid and was unanimous using 300.11(B) methods ( independent support wire ) attached deck to grid or securing directly to building structure not to others equipment.
 

kwired

Electron manager
Location
NE Nebraska
NFPA13 9.1.1.7 does not permit supporting any foreign materials. As far as supporting to water piping. gas piping, etc IPC, IMC, IFGC are a little silent but just more of a trade to trade thing as being respectful to others equipment. I did take some time today and contacted a few of my IAEI colleagues to discuss securing MC cable above grid and was unanimous using 300.11(B) methods ( independent support wire ) attached deck to grid or securing directly to building structure not to others equipment.
What about a unistrut that is supporting multiple trades items?

What if it is only supporting items associated with the same equipment - say refrigeration lines and electrical associated with that refrigeration equipment?
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
What I'm seeing the OP ask is whether the MC can be tied to the line set, not how to support the entire assembly. I'm sure he probably is supporting/securing the line set to something, he's just asking if he can tie his MC to the line set.
 

kwired

Electron manager
Location
NE Nebraska
What I'm seeing the OP ask is whether the MC can be tied to the line set, not how to support the entire assembly. I'm sure he probably is supporting/securing the line set to something, he's just asking if he can tie his MC to the line set.
I think that is what was originally asked as well.

I think NEC is mostly silent about it.

I also think it is somewhat acceptable between trades to secure wiring related to the line set or connected equipment to the line set.

Now if the wiring method would happen to be 2 inch RMC that might not be as acceptable, wouldn't really be allowed to support the line set from the wiring method either, though I myself wouldn't have much problem with that as long as the two items are associated with one another. With such association, if you remove one system chances are the other one is removed as well - you need both or nothing at all.
 
Let me say that I generally don't go attaching my stuff to anything I can even if it appears to be allowed. What instigated the OP was I am on a job that was started without permits. The HVAC guy pulled the line sets and the interconnect cable (here I would have supposed to have been pulled the interconnect cable as he is not an electrician). There generally isn't enough slack. To secure the cables to the building structure.
 

JGinIndy

Semi Retired EC,EI and Plan Review
Location
Indiana
Occupation
Retired Electrician currently County Inspector
Let me say that I generally don't go attaching my stuff to anything I can even if it appears to be allowed. What instigated the OP was I am on a job that was started without permits. The HVAC guy pulled the line sets and the interconnect cable (here I would have supposed to have been pulled the interconnect cable as he is not an electrician). There generally isn't enough slack. To secure the cables to the building structure.
In that situation and being you I would pass it as you seem to be a top notch electrician.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
If the electrical cable is to interconnect two pieces of equipment also interconnected by the line set, and if the mechanical code allows the cable to be suspended from the line set, what's the downside? This isn't some random cable hanging from some random unrelated utility.

How is the line set supported? Is there really no room to run a support wire around just the MC cable, back to whatever is supporting the line set?

Cheers, Wayne
 

JGinIndy

Semi Retired EC,EI and Plan Review
Location
Indiana
Occupation
Retired Electrician currently County Inspector
Just my educated opinion,
International Mechanical Code: IMC 305.2
Pipe hangers and supports shall have sufficient strength to withstand all anticipated static and specified dynamic loading conditions associated with the intended use. Hangers and anchors shall be attached to the building structure.

Personally I don’t see where it mentions attaching MC cable to it. But others may see it as it permits attaching. I discussed with several of my inspector colleagues ( located in areas across the nation ) and all agreed that 300.11(B) applies as being an above grid installation. Note: Obviously no issues with a typical 24v t-stat cable going along for the ride ( plenum rated if applicable ) 725.3(C) 300.22(C)(1)
 
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