water bonding and an awkward tenant

[Sintra]

if its a TT with 6mm i leave it but a TN if its not 10mm then i make it 10mm. if there is no bonding at all on a TT then we get told to put a 10 in anyway,
here's a question for you. is it allowed to bond the gas and water with the same 10mm cable if the conductor is not broken?
not hthst ive ever done that i have just come across it

Yes that is 100% ok to do.

 

[BristolSpark]

Can you use lugs on the earth straps when bonding

 

[Spudnik]

If running one 10mm, it is good practice to bond the water incoming before the gas if practicable.

 

[jimsky007]

Heres a question for you

If you are carrying out a PIR and the house that has 6mm bonding to water & gas what code would you give it in your report??

and would it fail overall because of it??

Is the house any less safe with 6mm than with 10mm

 

[robsparky1975]

i had some fun the other day with a job, i went to do an kitchen upgrade and complete minor works cert for it, while i appreciate the need to check gas and water bonding when you walk into a job i saw a 17th edition board and thought all was well. wrong. i had completed the work and went to test. the gas meter was right next to the board so the bonding was up to standard, the water stopcock was on the other side of the house and yes you guessed it. the lazy **** that put the board in could'nt be ***** to put it in. more to the point it was 4.30 pm and neither could i. so i rang my supervisor and asked if it was ok to go back and do it, 'no you cant leave site without bonding being up to standard, niceic code 1'. the tenant wasnt happy that i had to pull his carpets and boards up at that time of day.
what i actually want to know is because i do some work for myself where do i stand if the customer is not prepared to pay for the extra bonding if it was one of my own jobs?

hmmmm yes i had the same problem,but checked the main bonding before start of job so knew what was involved,a git of a route to water main but they always are,managed to get hold of sparky who had new shower circuit and 2way board installed asked him about why bonding not present when nic cert signed for 10mm gas/water,he said one of his subbies done it,a likely story,nic punish people for such things,anyway check out iet website for guidance notes on loads of different things like replacing consumer units etc,bonding first thing i check if not in then at clients expense,you can only trust yourself in this game.sad to see niceic registered installers cutting corners,not the first time ive seen this either,replacement consumer unit at job i went to and when i checked for bonding no gas bond?
sparky who installed it left a message to say 17th ed units dont need main bond because rcd protected?do u see what i mean,this guy must be about 110 years old.

 

[flukey]

Whats wrong with 6mm?

For TN-S or TT systems the csa of main protective bonding conductors must be a minimum of 6mm and not be less than half the csa of the main earthing conductor. 544.1.1

i must be one of them that doesnt understand it then unless your fitting 10mm main earthing conductors too

 

[pennywise]

what being able to get away with 6mm on a TN-S^?

 

[flukey]

what being able to get away with 6mm on a TN-S^?

no one said anything about getting away with it of course doing an adiababtic will give good cause to leave it in if proved suitable.

i was referring to sintras post

For TN-S or TT systems the csa of main protective bonding conductors must be a minimum of 6mm and not be less than half the csa of the main earthing conductor. 544.1.1

 

[pennywise]

Oh I see didn't mean it like a dodge or anything. The only time you could get away with 6mm on a TN-S would be if the main tails were 10mm and as you say 10mm main earthing conductors.

 

[flukey]

no mate i know you wasnt insinuating that

just seems funny stating that you can use 6mm and then posting that reg when the op is clearly about the incomer to a house cu where only an adiabatic would prove it to be ok otherwise in goes the 10mm

 

[pennywise]

I see what you mean about the OPs question ( just read up on adiabatic equation, sorted fancy word for cable sizing calc)

 

[flukey]

adiabatic is the name of the equation we use to size csa of a conductor and i personally would only use it in this instance if replacing the existing 6mm conductor was impossible and the maths proved the 6mm ok to remain in service