electricalforum.nz

Firstly, lets leave the debate around whether or not earthing is not require as I can't be bothered going in depth of the situation

My question is, is it acceptable to use a standard lug for this process? Although this is common practice and I have done so in the past I have just come across "BI-METAL REVERSE LUGS" on the Utilux catalog.

Is this the correct item that should be used? Much like when we use a bi metal lug for connection of ali cables to copper terminals or bars. When connecting copper to ali ladder for instance we should be using such product, correct?

Or is this normally not an issue in most cases and the standard practice is usually fine unless in areas at high risk of galvanic corrosion?

Is this more a case of should be used?

Curious of others thoughts

good question, never really though about it, I've always used copper lugs and never had any problems, never seen galvanic corrosion on ladder. I guess you could use the connection paste to exclude oxygen from the bolted joint.

Here is another question, what metal is the bolt made of - Steel? that's 3 different metals involved

Normal lugs are zinc-plated copper.
zinc is close to aluminium on the galvanic scale.
(closer than zinc & copper are!)
And unless you have moisture, you won't get much galvanic corrosion.
IF - and it's a big if - I wanted to earth the ladder I'd just use normal lugs
and maybe use an anti-corrosion treatment such as "lanocoat.

The sort of thing we should all be using on earth electrode connections - but almost nobody actually does.

Can also use jointing paste if you are concerned. The paste is mainly used on the jointing plates

And don't forget the galvo High tensile steel bolts and the belview washers + sealing paste for a good AL to AL joint.

AlecK wrote: ↑

Fri Feb 24, 2023 3:05 pm

Normal lugs are zinc-plated copper.
zinc is close to aluminium on the galvanic scale.
(closer than zinc & copper are!)

Normal lugs are tin plated. Tin & copper are right next to each other on the galvanic scale.

Apologies for the error