Electrical Bonding Sizes in Factory

[Carl Knowles]

Hello All,

We look after an old mill/factory and ive just been given the test remedials list another company did.
A bit part of it is bonding to steelworks and big gas pipework.

How do i determine size needed?
Is there a formula/table to work off?

 

[davesparks]

It depends on the nature of the incoming supply and any special requirements from the DNO, what is the earthing system?

I’m assuming it’s an LV intake here?

 

[LeeH]

Do you have a copy of that big yellow book?

 

[Deleted member 26818]

Do you have a copy of that big green book?

Wait, how old is this post?

 

[Deleted member 9648]

Have a butchers at the section in Bs7671 confusingly titled 'Main Bonding Conductors'. Might just tell you what you need to know!

 

[LeeH]

Wait, how old is this post?

My bad :mamazed:

It would have been close enough...

 

[Carl Knowles]

Thanks guys, im on page 171, table 54.8, guessing this might help!

 

[davesparks]

Thanks guys, im on page 171, table 54.8, guessing this might help!

Don’t guess as main bonding requirements are governed by more than just a table.

For a start what is the earthing system and size of the earthing conductor?

 

[Carl Knowles]

Ill find out all this information when next on site and get it posted on here.

Thanks for your help.

 

[westward10]

Could be interesting if they turn out to be supplied from a private transformer