Ground wire on roof

Status
Not open for further replies.
V

vargo320

Member
Location
US
Can you run a bare copper #6 ground wire directly on top of an asphalt roof over short distances? It is secured to the roof.

Sent from my SM-G930V using Tapatalk
 
V

vargo320

Member
Location
US
PV systems. Had a quality assurance guy write it up saying it can't be on the roof and should be protected in a raceway.

Sent from my SM-G930V using Tapatalk
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
The relevant code section says that an egc needs to be 6awg if it's not in a raceway. So the QA's argument doesn't hold water from a code standpoint. That said, it doesn't sound like a good practice to me and there might be another code argument against it. Also if this the QA guy not the inspector then there may be a quality standard he's enforcing that exceeds code. My personal quality standard would probably not allow it.
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
See 690.43 (F) if this is an EGC. If it's a 690.47(D) GEC then it's probably code compliant (although if I was the QA guy I'd probably ask you to remove it, but that's a whole other subject... :roll: ).
 
V

vargo320

Member
Location
US
jaggedben said:
See 690.43 (F) if this is an EGC. If it's a 690.47(D) GEC then it's probably code compliant (although if I was the QA guy I'd probably ask you to remove it, but that's a whole other subject... :roll: ).
Click to expand...
So for QA purposes it should be in a conduit?

Sent from my SM-G930V using Tapatalk
 
S

SolarPro

Senior Member
Location
Austin, TX
jaggedben said:
The relevant code section says that an egc needs to be 6awg if it's not in a raceway. So the QA's argument doesn't hold water from a code standpoint. That said, it doesn't sound like a good practice to me and there might be another code argument against it. Also if this the QA guy not the inspector then there may be a quality standard he's enforcing that exceeds code. My personal quality standard would probably not allow it.
Click to expand...

This wouldn't fly on one of my projects, but I agree the Code justification isn't self-evident. When in doubt, inspectors can just flag something that isn't installed in a "neat and workmanlike manner" [110.12].

My first question was: How is that copper secured?

You wouldn't want it screwed down to the roof, as that just creates an opportunity for water ingress. You really wouldn't want it sitting on the roof, as that creates a debris damn. It's hard to say for sure without seeing it, but it sounds dubious (as in there is probably a better way to get from Point A to Point B.)
 
C

Carultch

Senior Member
Location
Massachusetts
SolarPro said:
This wouldn't fly on one of my projects, but I agree the Code justification isn't self-evident. When in doubt, inspectors can just flag something that isn't installed in a "neat and workmanlike manner" [110.12].

My first question was: How is that copper secured?

You wouldn't want it screwed down to the roof, as that just creates an opportunity for water ingress. You really wouldn't want it sitting on the roof, as that creates a debris damn. It's hard to say for sure without seeing it, but it sounds dubious (as in there is probably a better way to get from Point A to Point B.)
Click to expand...


That's what I was thinking too. You can't just fasten it directly to the roof with a single screw at each interval, as that would cause the roof to leak. So would you plan on putting a Quickmount flashing with an Umpco loop clamp, strapping the wire every couple of feet, to carry this wire exposed on the roof between flashing devices?

Once you leave the footprint of the array, better to have it inside a conduit.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
SolarPro said:
This wouldn't fly on one of my projects, but I agree the Code justification isn't self-evident. When in doubt, inspectors can just flag something that isn't installed in a "neat and workmanlike manner" [110.12].
Click to expand...

Maybe they can but they should not.

No NEC inspector should be failing things just because they do not like it. If you can't find a code section directly on point then it is not a true safety issue.

Now on the otherhand customers can certainly have specifications that go well beyond the NEC.
 
S

SolarPro

Senior Member
Location
Austin, TX
iwire said:
Maybe they can but they should not.

No NEC inspector should be failing things just because they do not like it. If you can't find a code section directly on point then it is not a true safety issue.

Now on the otherhand customers can certainly have specifications that go well beyond the NEC.
Click to expand...


Right, which is typically the case with these QA inspections. The NEC isn't the only applicable code. Building codes and fire codes apply. There are also system performance and siting considerations. A PV system that is shaded all day is perfectly safe, but that system won't pass a QA inspection.

This is analogous to blower testing to ensure that a new build doesn't have excessive air leakage and that the HVAC ducts are properly sealed and balanced.
 
Status
Not open for further replies.
Top