Failed for non-continuous EGC on roof

[hitehm]

As I'm sure many of you can relate, we often have to use short to medium EMT runs to connect our PV wire between sections of the array split up by the roof faces. Over the ridges is a very common area for this. Since this is clearly an EGC (not GEC) we often use ground bushings at each end of the EMT for our bare #6 EGC so we don't have to run it inside our conduit with the PV wire. Well, we failed an inspection recently bc the inspector said it needed to be continuous and run inside the EMT. I found nothing in the 2017 NEC to support this. We use the typical SE Ungrounded HD wave inverters for all of our res installs. And of course, the same bare #6 is converted to stranded green inside the roof jbox to the inverter, which is obviously not continuous. I also looked at Unirac's spec sheets to see if they required it between rail sections and couldn't find anything.

So am I missing something?

 

[tom baker]

What section did he list as the violation?

 

[hitehm]

What section did he list as the violation?

From the inspector:
10.27.22 GEC/EQUIPMENT GROUNDING CONDUCTOR FOR ARRAY SHALL BE A CONTINUOUS COPPER CONDUCTOR. RACEWAY CAN NOT BE USED AS THE GEC/EQUIPMENT GROUNDING PATH. SEE YOUR PLAN SPECS AND NEC ART. 690

He is mistaking the roof EGC as a GEC. Ungrounded systems only need to bond the EGC to the building GEC per 250.130B. They don't require their own GEC, it is now optional per 690.47B.. Now of course if the house doesn't have a verifiable GEC at all then we always need to install ground rods from the main, which has nothing to do with the array having it's own electrode system.

 

[ggunn]

From the inspector:
10.27.22 GEC/EQUIPMENT GROUNDING CONDUCTOR FOR ARRAY SHALL BE A CONTINUOUS COPPER CONDUCTOR. RACEWAY CAN NOT BE USED AS THE GEC/EQUIPMENT GROUNDING PATH. SEE YOUR PLAN SPECS AND NEC ART. 690

He is mistaking the roof EGC as a GEC. Ungrounded systems only need to bond the EGC to the building GEC per 250.130B. They don't require their own GEC, it is now optional per 690.47B.. Now of course if the house doesn't have a verifiable GEC at all then we always need to install ground rods from the main, which has nothing to do with the array having it's own electrode system.

Like always in cases like this, you have to decide if it is a battle worth fighting. We ran into similar issues a while back, so we just run green wires through the conduit.

 

[jaggedben]

You are not missing anything code wise. But I wouldn't rely on typical grounding bushings to extend EGCs unless you are replacing the lugs with direct burial rated ones.

 

[wwhitney]

But I wouldn't rely on typical grounding bushings to extend EGCs unless you are replacing the lugs with direct burial rated ones.

Since it's on a roof, it needs to be wet location rated, which typical ones are not? And the simplest way to get one wet location rated is to get one direct burial rated?

Thanks,
Wayne

 

[pv_n00b]

It's just become the industry standard to run an EGC wire, it's not required by the NEC. But as you see, it's so common that if the AHJ does not see it they might call it out. I don't think conduit makes a reliable EGC for PV systems, I've seen too many broken conduits to believe they will hang in there for 20 years. You can fight it since it's not required by the NEC but I would instead encourage you to use an EGC wire.

 

[hitehm]

Like always in cases like this, you have to decide if it is a battle worth fighting. We ran into similar issues a while back, so we just run green wires through the conduit.

Appreciate all the replies and opinions. I agree to some extent on longevity but I hate failing an inspection based on incorrect code interpretation. All of our solar equipment for the roof is wet rated and ground bushings on both ends that thread are in my opinion pretty secure for continuity. #6 bare solid is a real pain to keep one continuous run while fighting it through multiple runs of emt. Bonding on both ends saves us time and effort so it's worth pushing back on. At very least I'd like the option to do so without failing inspection.

UPDATE: The code inspector reluctantly agreed with me and will allow it as long as it's not stated to do so on our plans.

 

[jaggedben]

Since it's on a roof, it needs to be wet location rated, which typical ones are not? And the simplest way to get one wet location rated is to get one direct burial rated?

Thanks,
Wayne

The only types of lay-in lugs I've seen are either not wet location or are direct burial. The ones that come on grounding bushings are the former. I don't know that I've ever seen anything in between.

 

[pv_n00b]

UPDATE: The code inspector reluctantly agreed with me and will allow it as long as it's not stated to do so on our plans.

That's interesting. I have to wonder what kind of stuff is going on in that building department as long as no one leaves a paper trail.