CU Change - No main earthing on water main. Polypipe incomer

[antimatter]

Simple answer - f$%k knows, anyone care to interpret for us?

 

[robsparky1975]

According to the on site guide,when polypipe incomer no main earth bond required as already pointed out,one of the first things i do when looking to upgrade to a new consumer unit is to check the sizing and connection of all earthing conductors,saves any problems later,anyway,one way of introducing earth potential might be an outside water supply in copper etc.mind you they say u dont need it on polypipe but on new builds i put it in just incase they change the regs in years to come and say its needed.

 

[Johno]

As already said, if it is a plastic pipe then no need to main earth bond, but you still need to make sure that the resistance is low between pipes and class II equipment in the bathroom (sorry I have forgot the formula) to rule out supplementary bonding.

 

[Johno]

If it were me having my assessment I would bond it.

 

[telectrix]

Bond it. they can't fail you for overdoing it, but they can if the assessor thinks it should be done and it ain't

 

[pushrod]

As already said, if it is a plastic pipe then no need to main earth bond, but you still need to make sure that the resistance is low between pipes and class II equipment in the bathroom (sorry I have forgot the formula) to rule out supplementary bonding.

touch voltage of 50V and current thru rcd of 30mA (0.03A) so R = V/I = 230/0.03 =1667ohms
if R is < 1667 Ω no supp bonding needed

 

[Des 56]

Aside from the main topic of whether main bonding is needed or not

If you decide that it is not going to be installed
You must carry out supplementary bonding in the bathroom because you can not meet the conditions for ommision
It has to be a building with protective equipotential bonding to do so

There seems to be a lot of opinion saying not required,my own understanding is that a full cooper system would require the main bond ,whereas if the supply and major parts of the plumbing are plastic then omit

 

[Spudnik]

Again, i agree with Des.

However, if im doing a rewire, then ill always throw in a bond, even if not needed due to poly incommer.

Wasteful? ... Maybe.

 

[nickblake]

Had a house that had no bond to water and a radial circuit with 4 sockets on it a cold water feed to a pump due to low pressure on the icoming main plugged into a socket on a radial plug a socket tester in all ok Zs the socket high readings , socket tester in reading unplug the pump earth fault the house was all plumbed in plastic but was finding a small earth through the water so there is still the potential from the water service be it only small its possible if its copper , but asringer has been said contact your trade body for advise,personally i would install the bond, always do

 

[Deleted member 9648]

IMO a main bond should be provided on the first available section of copper...even if the service is not introducing an earth potential at the time of the install conditions may change......CYA.

 

[antimatter]

As already said, if it is a plastic pipe then no need to main earth bond, but you still need to make sure that the resistance is low between pipes and class II equipment in the bathroom (sorry I have forgot the formula) to rule out supplementary bonding.

Sorry , but do you mean Class I?

 

[Johno]

Yes, well done for spotting my deliberate mistake.

 

[oldtimer]

4.4 OSG is saying you do not have to bond if both supply and house pipework is plastic but if supply is plastic and house is copper then recommend you earth it in other words earth the bl+%6 pipework if metal because if you dont then Jobs Worth inspector who is probably reading forums like this will pull you up for not doing so and why would he do this ? because he can and he has the power to say sorry you fail and I am just doing my job and this is how I show my manager nothing gets past me.
What I would say is this environment suffers from the lack of definition and open season on interpitation but what I have learned is if you go up against the people who police our trade then human nature dictates that they dig in because they can.