Residential PV system used quadruplex wire for a dettached structure to avoid trenching Project is in PA (NEC 2017) code cycle.

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Seandb1986

Member
Location
New Jersey
Occupation
Master Electrician / Electrical Applications Engineer
Hope this group of extraordinary skilled tradesmen could assist on this inspection citation for me.

Residential PV system on main house with a single string on the detached garage. I avoided the trench by using quadruplex 6-6-6-6 AL with messenger cable. Kept it 15ft above grade (>300v requirement) had a dc disconnect on 2nd structure.

Revised plans to match as built.

Inspector came back and stated that, there's been a recent update that the NEC no longer recognizes quadruplex OH cables being used. Due to it breaking down overtime & its only a "utility thing."

Any feedback would be greatly appreciated

Thank you
 
Inspector is correct it is not a NEC recognized wiring method, but too bad because it's a great product for the intended purpose.
 
Is there another recommended wiring method for OH runs AC or DC?

How would a contractor feed a pole barn if a trench wasnt an option?
 
Im reading into this a bit more and it seems that xple is the insulation NOT the conductor type. Or is that a gray area?based on interpretation?
 
I would approve that installation based on this "Other factory-assembled, multiconductor control, signal, or power cables that are identified for the use" found in Table 396.10(A).
Remember that Identified, stops short of listed.
Identified (as applied to equipment).
Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement. (CMP-1)
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The fact that there are thousands of miles of this type of cable in use, tells me that it is "recognizable" as suitable for this purpose.

However this would be a judgement call by your AHJ.

As far as I know, there has never been any language in the NEC that specifically permitted quadplex or triplex cable assemblies that have a bare neutral/messenger conductor.
 
don_resqcapt19 said:
I would approve that installation based on this "Other factory-assembled, multiconductor control, signal, or power cables that are identified for the use" found in Table 396.10(A).
Remember that Identified, stops short of listed.

The fact that there are thousands of miles of this type of cable in use, tells me that it is "recognizable" as suitable for this purpose.

However this would be a judgement call by your AHJ.

As far as I know, there has never been any language in the NEC that specifically permitted quadplex or triplex cable assemblies that have a bare neutral/messenger conductor.
Click to expand...
The messenger conductor is just used for support. The insulated conductors are either positive, negative, & ground(DC). OR phase 1, phase, & neutral, (messenger is the ground for AC)
 
Seandb1986 said:
The messenger conductor is just used for support. The insulated conductors are either positive, negative, & ground(DC). OR phase 1, phase, & neutral, (messenger is the ground for AC)
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It depends on the installation...every triplex installed by a utility uses the messenger as the neutral conductor.

However, it would be rare that you could do that in an NEC installation and the messenger for an NEC installation would be the Equipment Grounding Conductor.
 
I agree it is difficult because the conductors are not marked with an NEC designation.

What Don said is a good way of saying it could be OK anyway.

Aside from that issue, I have always figured that quadplex is OK for the purpose, because the messenger would be the bare EGC, and the 3 insulated would be 120/neutral/120 anyway.

Aside from that, the bare part could be considered "bare wiring on insulators" which is an allowable method.

Besides all that, if you really need to preserve the installation and bow to the inspector, SER cable supported by a messenger would be allowed under all the normal interpretations. But it would be dumb and a worse installation than just the quadplex.
 
Seandb1986 said:
Is there another recommended wiring method for OH runs AC or DC?

How would a contractor feed a pole barn if a trench wasnt an option?
Click to expand...
I'm not saying to give up on using quad, but just to answer this question:

You can do messenger supported wiring per article 225. Basically you take some wire rope and lash or fasten conductors or SER cable to it. You could use a product like this:

Aerial Support Ties

HellermannTyton Aerial Support Ties separate two bundles in parallel routing applications, such as fiber and coax cables running beneath messenger wires with an all-in-one design.
www.hellermanntyton.us www.hellermanntyton.us
 
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