By now, many of you probably realize, as I do, that "plug and play" modules such as the Sharps are not quite, because of the NEC requirement to ground the module frame, and John Wile's interpretation that you can't just ground the aluminum mounting rack, but need to run a wire to each and every module.

Does anyone have any good ideas on how to do this? I 've also read in the NEC that bare ground wires smaller than #6 must be in conduit for protection. Maybe I could "bond" each module frame to its aluminum rack, and then connect all of my racks to the grounding conductor. Certainly this would be easier, look better, and also have lower resistance and impedance than a "tree" of ground wires. Just thinking out loud...

Jerry

I used the Sharp 175's, and I drilled a new hole, used a self-tapping SS screw and a "donut" washer to capture a #10 ground wire connected daisy-chain to all the modules. It wasn't too hard but it took a while. I look forward to a racking supplier coming up with a better way. On the racks I have (Tile Trac) it could have been accomplished with some set screws in the clamps themselves.

Hmmm. I requested a drawing from Sharp and noted that there is a hole on the bottom (on one side only, offset slightly from the middle) which is marked "2.3 dia for grounding". But it's on the bottom. ARGHHHH!!!

But you gave me a good idea. Did you drill your holes on the top or on the edge? Then they would be much easier to get to, but maybe more "subject to damage". Were there any comments from your friendly neighborhood electrical inspector?

Jerry

>I requested a drawing from Sharp and noted that there is a hole on the bottom (on one
> side only, offset slightly from the middle) which is marked "2.3 dia for
> grounding". But it's on the bottom.

Yep, and the screw they supply for grounding is a joke. I think it's a 2-56.

>But you gave me a good idea. Did you drill your holes on the top or on the edge?

On the top on the 'top row' and on the bottom on the 'bottom row' of panels. Made it easier to wire. Neither inspector (city or SDG+E) squauked about it.

The NEC 2002 250.120C Talks about if Equipment Grounding conductor smaller than 6 AWG is located in a place free from physical damage can be without "raceway of cable armor". Wouldn't modules on a roof be considered a protected place?

I've heard of (but not yet seen) a style of "lay in" lug which could be bolted to each frame via a SS bolt or self-tapper. This would hold a grounding wire more securely than the washer (but they're going to be more expensive).

I saw one array that used a continuous ground wire passing through a lug on each panel. For removal just unscrew the entire lug.

Here's a link to the part:
http://www.grainger.com/Grainger/productdetail.jsp?ItemId=1611765473

$.74/panel isn't that bad.

Sean

Hi Sean,

That lug is not listed for outdoor use.

Oops.

Is it possible they used an outdoor rated lug and I just provided a wrong part number, or is that not correct at all?

http://www.extremepowersolutions.com/products/solar/rvmounts.htm
The bottom picture is from a Kyocera panel catalog.

Sean

The part that you showed is a tin plated aluminum lug. Nobody makes a tin plated aluminum lug that is outdoor rated.

The Kyocera lug looks like a copper one. Most of them (but not all) are not rated for outdoor use.

There is a tin plated copper lay-in lug with a stainless steel screw that is outdoor listed. I will try to find the part number.

Ron