17th bonding ... again.

[Robbo]

Right, under 17th edition regulations if a bathroom has (lets say) a light, extractor fan and a shower. And each circuit is protected by a 30mA RCD back at the distribution board.

And lets say there is a 10mm earth clamped to the incoming water mains and another 10mm earth clamped to the incoming gas. The main earthing conductor is in place and is 16mm.

And if these circuits disconnection times comply.

Then *waits for the onslaught* there is no need for supplementary bonding/cross bonding in a bathroom????

I was led to believe this when I did my 17th update course. The lecturer wasnt too pleased with the change. Being a bit old school I remember him being happy to tell people to still bond in bathrooms as "you are relying on an RCD which is only a mechanism that could still jam or become faulty over time if regular tests are not carried out etc"

I havent seen anyone running an earth around a bathroom since the introduction of the 17th, but I still see people cross bonding pipes at combi boilers and I get confused. Is this a requirement or isnt it? Or would it just be the odd spark who, like my old college lecturer, do not trust the RCD and would rather take the extra precaution?

 

[stringy]

i was under the same impression as you robbo, my boss tells me to cross bond combi boilers but just says its good practise.

since the 17th has come in we never do suplementry bonding in bathrooms just rcd.

makes life a lot easier lol

 

[montybaber]

Yep no need for supp bonding as long a disconnection times are ok ie; RCD's

 

[Monkeyboy]

Just to chuck a spanner in................ No need for cross bonding.............unless manufactures instructions ask for it (Boiler manufacture)

Mark

 

[sirsparkabit]

i was under the same impression as you robbo, my boss tells me to cross bond combi boilers but just says its good practise.since the 17th has come in we never do suplementry bonding in bathrooms just rcd.

makes life a lot easier lol

Bonding combi boilers is a joke and makes no sense whatsoever to me, have a look under the combi at the pipes and you will see a metal plate that the pipes are passing through,

now you come along and join them all up again with earth cable:O

Think about it lads you dont have to follow the crowd.

A bit of testing should confirm if they are earthed

 

[Monkeyboy]

You're right you don't have to follow the crowd!

But you DO need to follow the manufactures instructions! It's in the 17th can't quote it now bit it's there!

Mark

 

[PAUL M]

i dont cross bond the boilers unless as stated as requirement by manufacturer but hey if a plumber wants to waste his time doing it then i wont argue ] regards bathrooms most of the new bathrooms are in plastic pipework anyways

 

[montybaber]

lazy old wet trades

 

[SPECIAL LOCATION]

You're right you don't have to follow the crowd!But you DO need to follow the manufactures instructions! It's in the 17th can't quote it now bit it's there!

Mark

Pg 19

last sentence of 134.1.1. ERECTION! {oops morning vicar!Pray}

 

[RookieDI]

lazy old wet trades

OI ! I do wet trades as well

and looking to do Gas sometime next year

 

[montybaber]

never mind

 

[SLIPSHOD & SLAPDASH]

But if the pipes are extraneous, that is... likely to bring in an earth potential, say if any are buried in a slab or run out to a outbuilding, then they must be bonded back to the MET

 

[marksy sparky]

Lets Leave The Plumbers Alone They Can T Help It .........

But I Dont Think The New Regs Are 100% Clear On Bathroom Bonding Its All Down To How You Read It Yourself........

 

[Apache]

Lets Leave The Plumbers Alone They Can T Help It .........But I Dont Think The New Regs Are 100% Clear On Bathroom Bonding Its All Down To How You Read It Yourself........

They seem quite simple. Bonding required, supp bonding not required except slips version below.

But if the pipes are extraneous, that is... likely to bring in an earth potential, say if any are buried in a slab or run out to a outbuilding, then they must be bonded back to the MET

 

[patspark]

corgi are the ones who insist on cross bonding boilers

 

[Apache]

corgi are the ones who insist on cross bonding boilers

And they have no jurisdiction over sparks

 

[batty]

Hello Robbo welcome to the forum. As far as I know if all circuits in the bathroom are RCD protected no supplementary bonding is required. But my thoughts are the regulations change. I have thought supplementary bonding metal sinks in a kitchen is a good idea as I have been to two jobs where people have got shocks off sinks both where not bonded. If they had been maybe the faults would have cleared.

Batty

 

[sparkyork]

also to have no supp bonding in bathroom the main equipotential bonding needs to be up to scratch as well.

 

[patspark]

And they have no jurisdiction over sparks

next year they will have no jurisdiction over any one i have had gas fitters

refuse to commission boiler because it was not cross bonded when asked to quote a reg he could only say it was a corgi reg i dont know where they get such nonsense

 

[Shakey]

Right, under 17th edition regulations if a bathroom has (lets say) a light, extractor fan and a shower. And each circuit is protected by a 30mA RCD back at the distribution board.And lets say there is a 10mm earth clamped to the incoming water mains and another 10mm earth clamped to the incoming gas. The main earthing conductor is in place and is 16mm.

And if these circuits disconnection times comply.

Then *waits for the onslaught* there is no need for supplementary bonding/cross bonding in a bathroom????

I was led to believe this when I did my 17th update course. The lecturer wasnt too pleased with the change. Being a bit old school I remember him being happy to tell people to still bond in bathrooms as "you are relying on an RCD which is only a mechanism that could still jam or become faulty over time if regular tests are not carried out etc"

I havent seen anyone running an earth around a bathroom since the introduction of the 17th, but I still see people cross bonding pipes at combi boilers and I get confused. Is this a requirement or isnt it? Or would it just be the odd spark who, like my old college lecturer, do not trust the RCD and would rather take the extra precaution?

Rob,

dont forget the requirement to ensure that any extraneous paths are 'effectively connected' (ie less than the magic 1667 ohms) to the main protective bonding

But of course, if the reading is higher than that, they are probably not extraneous paths anyway (ie hepworth fedding copper) and wouldnt need bonding

on a side note, i saw a diagram of a bathroom from a 'leading' manufacturer the other day, which showed the bathroom sink having its own zones!!!!! I will dig it out - crazy fools!