[RE-wrenches] Are Stainless Steel Star Washers UL 467 compatable?

R Ray Walters ray at solarray.com
Wed Apr 20 20:39:10 PDT 2011


I recall Bill Brooks noting that the ILSOC ground lugs needed full contact of their back surface with the surface it was mounted to. He was recommending grinding off the oxide coating on the module around the screw hole to achieve the desired contact. Apparently putting a star washer between the lug and the surface didn't meet the UL listing for the lug.
Personally I'm a WEEB guy these days.

R. Walters
ray at solarray.com
Solar Engineer




On Apr 20, 2011, at 9:15 PM, North Texas Renewable Energy Inc wrote:

> Dan
> if I recall from my younger days as a wrench [car], star washers work properly only when turned while being crushed. The rotation causes the tines to dig into both surfaces and literally gouge out metal to lock itself in place.
> Simply compressing a star washer between aluminum and a ground lugs surfaces won't have the same effect of gouging thru the aluminum oxidation into fresh metal. It's the same principle used in the WEEB style grounding washers, you got to penetrate.
> That's why star washers are still allowed for grounding several brands of modules using those cheezy wire-around-the-screw OEM ground assemblies.
> Jim
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org]On Behalf Of dan at foxfire-energy.com
> Sent: Wednesday, April 20, 2011 4:02 PM
> To: RE-wrenches
> Subject: [RE-wrenches] Are Stainless Steel Star Washers UL 467 compatable?
> 
> I'm struggling with where I came up with the notion that Nolox coated Stainless Steel Star washers  under copper drop-in ground lugs for grounding module frames are NEC compliant. Can't seem to lay me fingers on it in the 2011 NEC. I'm wondering if this might be yet another "Former Life" things. UL467? a manufacturer specific thing? I'm confoosed and I want to go outside and play. db
> 
> 
> Dan Brown
> Foxfire Energy Corp.
> Renewable Energy Systems
> (802)-483-2564
> www.Foxfire-Energy.com
> NABCEP #092907-44
> 
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