could this be the panel bonding screw

[Robert Foster]

What do you think, could the screw I've arrowed in the attached photo be the main panel bonding screw in this older Cutler Hammer Panel ? The screw does not have very good contact to the busbar but it is the only device I can see that could possibly be considered. I'm leaning towards reporting no visible bonding device but wanted to get a second opinion or two.

Thanks.

[John Arnold]

The screw you indicate looks similar to the one on the bottom right which appears to be passing through plastic, in which case it probably ain't the bonding screw.
That hole just above your arrow looks like a possible location for a bonding screw.

[Robert Foster]

I agree, it does look similar except for the star washer under the screw in the bottom right. There is another screw in the upper left, that you cannot see in the pic, which is identical to the one in the bottom right. The star washers suggest to me that those two screws are for fastening the plastic isolator to the panel case.

That hole does look like the location you'd expect to see the bonding screw, except the hole is not threaded and the plastic isolator is behind that hole preventing any screw inserted from contacting the panel case.

I'm not sure what that screw I've pointed to does....if it's not the bonding screw and it's not helping to secure the plastic isolator...what is it for? :confused:

[Scott Patterson]

I do not see a proper bonding screw or strap on that panel. I would report it as such. With that type of configuration I think you would be more inclined to see a bonding strap over a screw.

Is that the service equipment panel?

[Jim Port]

The location of the bonding means is typically shown on the panel label. Often times as a black dot in the buss arrangement.

[Robert Foster]

The location of the bonding means is typically shown on the panel label. Often times as a black dot in the buss arrangement.

I didn't know that....thanks...


I do not see a proper bonding screw or strap on that panel. I would report it as such. With that type of configuration I think you would be more inclined to see a bonding strap over a screw.

Is that the service equipment panel?

Yes, sorry...

[paul hardy]

That could be the bond screw seems to me that crouse-hinds made panels were the screw was just to the side of the bar and the screw would thread into the back of the panel and the head would catch the bar.