554-05-02

[securespark]

Just been browsing the 16th for a topic posted elsewhere and am wondering about this reg:

554-05-02 All metal parts of the heater or boiler which are in contact with the water (other than current-carrying parts) shall be solidly and metallically connected to a metal water pipe through which the water supply to the heater or boiler is provided, and that water pipe shall be connected to the main earthing terminal by means independent of the circuit protective conductor.


...and that water pipe shall be connected to the main earthing terminal by means independent of the circuit protective conductor.

Normally this was done by fitting supplementary bonding, but the regs did not specify whether the connection to the MET ought to be direct or indirect.

 

[EFLImpudence]

554.3.2

411.3.1.2
(i) Water installation pipes
(iv) Central heating ...

 

[Spark123]

The regulation set Securespark refers to is for "water heaters having immersed and uninsulated heating elements" such as electrode heaters which pass current through the water or an uninsulated element, not your normal immersion heater or boiler.

 

[securespark]

Yeah, sorry. I should have made it clear.

But nevertheless, my query stands. I only ever did one heater like that in a hospital, and we took bonding back to the MET (rightly or wrongly).

But having looked back at that reg, I'm not sure that was correct, but the book does not make it clear.

 

[JohnW2]

But nevertheless, my query stands. I only ever did one heater like that in a hospital, and we took bonding back to the MET (rightly or wrongly). But having looked back at that reg, I'm not sure that was correct, but the book does not make it clear.

Taking the bonding back to the MET surely would have been OK, even if not 'required', wouldn't it - simply an unnecessary use of cable if local bonding would have been sufficient to satisfy the regs?

Kind Regards, John.

 

[sparkticus]

Just been browsing the 16th for a topic posted elsewhere and am wondering about this reg:

554-05-02 All metal parts of the heater or boiler which are in contact with the water (other than current-carrying parts) shall be solidly and metallically connected to a metal water pipe through which the water supply to the heater or boiler is provided, and that water pipe shall be connected to the main earthing terminal by means independent of the circuit protective conductor.


...and that water pipe shall be connected to the main earthing terminal by means independent of the circuit protective conductor.

Normally this was done by fitting supplementary bonding, but the regs did not specify whether the connection to the MET ought to be direct or indirect.

Local bonding is fine provided the "metal water pipe" is really all copper/metal (not plastic somewhere along the line) These direct electrode units can develop high earth leakage currents so the main CPC is very important too but I don't like to rely on that alone (I always worry about someone disconnecting plumbing etc) I have, on occasions run a separate suitably sized G/Y back to the MET on these types but only when uncertain of pipe continuity. Are you referring to a specific type (single phase, three phase etc) or are you just browsing in general?