Swimming pool

[Jimmyb]

Hello, Ive been doing some work for a neighbour who has just moved into a house with a swimming pool, i couldnt help but have a look at the wiring for the pool ect, the pool is heated by a gas boiler and has a electric pump, this was fitted last year and has been signed off.
The problem i have with it is the supply is tncs and i know that all swimming pool equipment wasnt allowed to be installed on to this type of supply, so i thought id rang the sparky that installed it to see what he said, the reply i got was 'because its only the pump then its ok'.

Is he right with this ?

thanks jimmy

 

[Deleted member 9648]

7671 does not prevent a TNCS supply being used for a pool,however depending on the zone it may be neccessary to install a bonded grid which is not generally practical...702.410.3.4.3.
As long as the pump is outside the zones and the pipework into the pool is plastic a TNCS supply can be used.....section 702 needs to be consulted to get the full picture though.

 

[Electro-tech]

Im going to mention it for old times sake, as above regards 7671 but the only concern is a broken PEN Conductor. However a small voltage difference between the PME earthing terminal at the origin of an installation and true Earth potential may exist.
This Small voltage above Earth potential could under certain conditions such as reduced body resistance due to the presence of water, create the posibility of a perceived electric shock for a person in contact with a conductive part(a handrail connected to the supplementary bonding) and earth Potential ( ie,uninsulated Wet floor etc.) Swimming Pool may be made a TT system,where the exposed conductive parts and extraneous conductive parts are seperated from the PME earthing Terminal.

 

[Engineer54]

You wouldn't normally connect the pool earthing arrangement ( concrete re-bar, earth rods etc) to a PME derived system, they would remain separated. Nothing stopping you using a PME system to supply the pool pumps, heaters banks etc, they will normally be located outside of the zones anyway.

If the pool system was supplied from a TN-S or TT system, then the pool earthing arrangements can be bonded back to the pool installations EMT. ...My earthing system is TT so my pool is bonded back via the EMT to the MET which in turn gives me an extremely good overall Ra value to my installation....

 

[Knobhead]

And yet another contender for the Gibberish Generator award

 

[Silly Sausage]

I suspect it's a case of Polish to English online translation.

 

[Knobhead]

I wonder what “Gibberish Generator” translates to in Polish?

 

[Edd]

You wouldn't normally connect the pool earthing arrangement ( concrete re-bar, earth rods etc) to a PME derived system, they would remain separated. Nothing stopping you using a PME system to supply the pool pumps, heaters banks etc, they will normally be located outside of the zones anyway.

If the pool system was supplied from a TN-S or TT system, then the pool earthing arrangements can be bonded back to the pool installations EMT. ...My earthing system is TT so my pool is bonded back via the EMT to the MET which in turn gives me an extremely good overall Ra value to my installation....

Old thread I know, But as someones brought it back to life i will coment. As E54 Says great stuff. But I wonder why people are happy to connect hot tubs up without such thought..