Serrated washers on steel conduit

[Rocboni]

Yes but no longer teaches, used to come in to cover the odd day right up to last year, he's got two young (less than 5) kids and an Asian wife!

Who did you serve you're time with?

 

[streamer]

Blimey! He did have a young Asian 'friend' when I was there.
We used to call him Yoda! Malcolm Hood was the other one who taught us but he's back on the tools now.

 

[davesparks]

I occasionally come across installations where serrated washers have been used, but they are normally older installations not recent ones.
A local theatre has a conduit installation where serrated washers were used throughout and I think that part of the installation dates from the 1970's

 

[Rocboni]

Our college completed in 2012 has them on everything, so still goes on, I do like them but doesn't look like I can justify them really.

 

[handyosprey]

Serrated washers should be used in conduit/trunking installs. If you are fitting a complete c/t install why use earth cables ? Serrated washers at the trunking/bushing only side is acceptable where conduit forms part of a surface installation.

I dont get why anyone would design a metal c/t install with earth cables unless the place is prone to corrosion.

 

[Rocboni]

The system in this particular install was designed by building services consultants and contains cpc's for all circuits. But I do agree, I personally don't think it makes a difference wether it has or not, I like to see the washers!

 

[davesparks]

Serrated washers should be used in conduit/trunking installs. If you are fitting a complete c/t install why use earth cables ? Serrated washers at the trunking/bushing only side is acceptable where conduit forms part of a surface installation.

I dont get why anyone would design a metal c/t install with earth cables unless the place is prone to corrosion.

And if it is prone to corrosion then steel containment is not the most suitable solution

 

[ipf]

Serrated washers, who cares with bushes anyway?
Here's one for you....with serrated holes?

 

[ruston]

Serrated and spring washers were mainly used for security as Marvo has said.
Locknuts used to be common too , Along with castellated nuts and split pins.
Then came the nyloc..