Need Earth Ground Without Drilling a Hole

"Can't"????? How did you *type* the query?

Do you mean if I checked Google? D from BC

How is a PEM fastener going to work if you can't drill a hole? Either I'm missing something here, or....

I didn't express the problem accurately... Better expressed: I need to bond a ground wire inside a box but I don't want to create any external protrusions. There are PEM's that can be countersunk and have thin heads.

Someday I'd like to weld an aluminum bolt to the inside of the box for an earth ground connection. Anybody here do little welds like that?

D from BC

No, i meant "do you have arms and hands?"

How about a spot welder?

Yup.. No missing parts... I just "can't" think of a clever way of bonding a ground wire to an aluminum box.

It's done now.. PEM will be used next time and welding will be down if I learn welding and find it worthy to get the equipment. The welder might look good next to the scope :) D from BC

If the hole itself isn't the problem, but you have to avoid anything projecting on one side of the panel, drill a countersunk hole and use a conventional countersunk rivet.

(Assuming there is anyone left who still remembers how to close a rivet by hand.)

I guess 4 spot welds might be enough to hold a 4mm wide threaded stud on an aluminum box. The stud is so small, welding all around adds very little time.

D from BC

Countersink rivets!... That exists!? I'll check with my fastener suppliers. D from BC

how do you intend to limit the fault current to 15A?

Bye. Jasen

I've got a bag of them that I bought a couple of years ago from a local metalwork supplier. You could always machine one up in the lathe if you are just making a one-off job.

If the panel is too thin to drill a decent countersink without weakening it, it should be possible to deform the metal to the required shape. <

A 15Amp draw trips the circuit breaker in the electrical room. I'm using the breaker trip level as a guide to know how much current the ground connection should handle in the event of a short circuit.

For example, during a fault, a soldered earth ground wire might melt by the time the 15amp breaker trips in the building electrical utility room. D from BC

Cool.. :) D from BC

Let's say this is the screw ( ==

Not that anybody's noticed. ;-)

That's nothing new - Superman was walking through walls in the 1950's, by interleaving his molecules with the wall's. ;-)

How about a countersunk hole and a flat-head screw?

Good Luck! Rich

PEM has studs which are spot welded on. (I think it was PEM, but it was also 25 years ago). But you'd need to find a sheet metal shop that had the custom welder for a one-off.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)