Domestic main earth and main bonding

[pushrod]

Just wondering what people generally do when these are missing or very old and obviously not up to the job. Do you put 16mm and 10mm in regardless or do you actually calculate it and see if 10mm and 6mm would satisfactorily cope.
Reason why i ask is i was in a large diy store and was shocked at the price of 16mm green and yellow . I know you could buy it in bulk cheaper elsewhere, but i bet it must still be fairly pricey.

Also anyone got a link to a crimp? to help terminate a large cable into a smaller hole - I think Lenny posted one a few months back but i foolishly didn't bookmark it.
cheers.

 

[Guest123]

25mm Copper Pin Terminal




If theres no bonding at all present then in go the 10mm bonds, main earth will be changed to 16mm.

If on TN-S, bonding is 6mm then providing there's no obvious signs of damage or breakdown/overheating and an adiabatic to double check then usually it wont need upgrading.

TN-C-S, minimum 10mm bonds and 16mm earth.

 

[pushrod]

Cheers Lenny - Hadn't previously realized that 16 and 10 were the absolute min for a PME (found the relevant section in the BRB now)

 

[rocker]

For God's sake don't buy any cable from a DIY store. Ever.

Had to buy three poxy meters of 16 mil earlier for a job in the morning. Went to my wholesaler (Total in Newport - top boys) at a minute after five - sorted me out the three meters AFTER closing time cost me 2.87. Also gave me the time of day even though he surely wanted to get home.
Just as he's printed my order I realise I need a bit of top hat. I don't want to bother him now as we're knocking on 10 past and he's probably not getting paid for this. I jump in the car and head over to a well known DIY store (who've got their name on it), picked up my top hat and had a brief gander at their earth cable.
2 meters of 10 mil (not 16, 10) - 6 quid odd. They are total rip off merchants.
I don't want to sound patronising, I don't know if you're old or new - but don't be afraid of going in the wholesalers, they are mainly well helpful to new customers and only take the **** out of you when they know you!

To answer your initial question, just put 16 main and 10 bonding every time. If you buy it in a decent place it's pennies difference - you would spend the money in 'wages' with the time spent working it out! Plus who knows, even if youre on holiday next time they need their shower putting in that tips the balance and requires bigger tails/bigger earths/bigger bonds, they may get an honest spark in to do it for them, and he may say 'well whoever put this in has sorted you out, he's made sure you don't have to upgrade this lot at his own expense'. Alright it's unlikely, but if it happens you're in that customer and all their friends' good books.

Also, that tool - are you talking about something that will 'squash' the wires so that they will fit in the sort of terminations that Wilex/Crabtree reckon are acceptable (i.e. the same size hole they give you to terminate a bit of 2.5 mil)? If so, I would be very VERY interested in any information on this tool!!!!

 

[Guest123]

they need their shower putting in that tips the balance and requires bigger tails/bigger earths/bigger bonds,

I'm intriged, why would the installation of a shower necessetate larger bonding conductors????

 

[rocker]

Good point.

 

[ezzzekiel]

dont use adiabtic to size main bonding conductors