LFMC support

[electrofelon]

Ok what do y'all think of this one. This is a PV system I did. Sorry for the not so great picture. This was a third party "quality" inspection from the state because the system was done under their incentive program. Code section cited was just 350.30, with the description "Circuit conduit or raceway lacks adequate support. Conduit is secured with plastic wire ties.". You can't tell from the picture, but these are the heavy duty 3/8 wide wire ties not the little skinny ones. I think it is hogwash.

What alternative could be used? I thought about a minerallac, but I think that would look awful. Maybe a hose clamp?

I'm actually not going to "fix" it, as it is a minor enough violation they are not requireing photo documentation that it was changed.

 

[Ponchik]

Bolt a 6" wide board on the back of the "U"channel and use two hole strap to support the conduit to the board.

Some inspectors "HAVE" to say something, because they can't find anything to cite.

 

[ptonsparky]

Cable ties for us are required to have a load rating and of course sunlight resistant. I've used standoffs but would prefer your cable ties.

 

[Chamuit]

He's got you. If the inspector is an agent of the AHJ and he doesn't approve, you need to comply.

 

[electrofelon]

Bolt a 6" wide board on the back of the "U"channel and use two hole strap to support the conduit to the board.

Some inspectors "HAVE" to say something, because they can't find anything to cite.

Yeah some treated lumber and 2 hole straps should be bullet proof inspection wise. But I do think my method is cleaner looking.

 

[Chamuit]

Yep, your installation is tight.

 

[electrofelon]

He's got you. If the inspector is an agent of the AHJ and he doesn't approve, you need to comply.

View attachment 2564430

Well this is an interesting situation. It's not real clear-cut who is the AHJ here. Here in upstate New York we have private third party electrical inspectors, so I would say they are the AHJ. My electrical inspector passed/approved this. The state agency that distributes the rebates has some sort of stake in it but I would have to go through the program manual to look at the exact wording.

 

[wwhitney]

350.30(A) (2017 and later) specifically allows cable ties "listed and . . . identified for securement and support" on LFMC. So did you use the correct type? If so I suggest supplying the code reference and documentation on the cable ties used.

Cheers, Wayne

 

[electrofelon]

350.30(A) (2017 and later) specifically allows cable ties "listed and . . . identified for securement and support" on LFMC. So did you use the correct type? If so I suggest supplying the code reference and documentation on the cable ties used.

Cheers, Wayne

Oh interesting I forgot about that, I was looking at the 2014 just because I had that handy. Which or how many cable ties are listed for support?

 

[Electromatic]

I've wondered the same thing about cable ties. Many wiring methods mention them in their .30 sections, always saying "listed and identified". Do they need some kind of electrical listing for each cable or conduit type? If the package identifies them as capable of supporting _x_lbs., does that suffice?

 

[ptonsparky]

Capable of supporting _x_lbs works for us.

 

[electrofelon]

I've wondered the same thing about cable ties. Many wiring methods mention them in their .30 sections, always saying "listed and identified". Do they need some kind of electrical listing for each cable or conduit type? If the package identifies them as capable of supporting _x_lbs., does that suffice?

Capable of supporting _x_lbs works for us.

Is there a listing standard for cable ties used as conduit support? How many pounds strength would I need? Is that defined somewhere? This seems like another genius CMP move to me.

 

[ptonsparky]

It is a 'cable tie'.

 

[electrofelon]

It is a 'cable tie'.

Come on now, let's tone back the common sense a bit and bring it back to NEC territory.

 

[Johnhall30]

Install looks good to me

 

[don_resqcapt19]

Is there a listing standard for cable ties used as conduit support? How many pounds strength would I need? Is that defined somewhere? This seems like another genius CMP move to me.

Yes there is. The following is from the UL Guide Information for Positioning Devices (ZODZ).

Type Classification –
Type 2 or 21 – Products are investigated to maintain the declared loop tensile strength (cable ties) or mechanical strength (fixing devices) after environmental exposures.
Type 2S or 21S – Products are investigated to maintain the declared loop tensile strength (cable ties) or mechanical strength (fixing devices) after environmental exposures. Strength is retained for a prolonged specified time and are suitable for use as primary support of flexible conduit, flexible tubing, or cable as defined in ANSI/NFPA 70, "National Electrical Code" (NEC). Declared strength shall be at least 220 Newtons (50 lbs). Such product may be marked “Support” in lieu of the “S” designation.

 

[jap]

Looks good to me, although I'd of probably hard piped the whole thing.

JAP>

 

[electrofelon]

Yes there is. The following is from the UL Guide Information for Positioning Devices (ZODZ).

Thanks Don

 

[electrofelon]

Looks good to me, although I'd of probably hard piped the whole thing.

JAP>

It's pretty common to use LFMC to PV inverters. Sort of like how we use flex to transformers - not really sure it's necessary or why we do it but why change

 

[synchro]

It's pretty common to use LFMC to PV inverters. Sort of like how we use flex to transformers - not really sure it's necessary or why we do it but why change

Is the conduction of noise through hard piped conduits ever an issue? If so, it's probably less of a problem with the usual "transformerless" inverters.