DNO supplied isolator , only one pole used.

[photon]

I asked for my DNO to fit an isolator between my meter and my consumer unit to avoid any need to get the supply fuse pulled when I have a new kitchen fitted in the summer.

They put in a double pole switch in an enclosure.

However only the live (phase) conductor goes to the switch
(ie 1 cable in 1 cable out , second pole left unused.)

The neutral cable goes to a henley block then direct to the consumer unit.

I had expected the double pole isolator to be used to switch both phase and neutral.

Is this the usual arrangement.

 

[TONY144]

what did they charge you please if you dont mind?

 

[Adam_151]

what did they charge you please if you dont mind?

It depends on the area, some DNOs will do it free of charge, others will flat out refuse, etc

 

[andy]

double pole are usually fitted, but aslong as the phase is switched, there shouldnt be too much of a problem

 

[ebee]

If it`s TNC - S (PME) then switching your Nuetral would also switch out the incomming earth therefore only phase is switched

 

[Lectrician]

If it`s TNC - S (PME) then switching your Nuetral would also switch out the incomming earth therefore only phase is switched

Not so - the earth comes from the service head, the isolator is placed in the meter tails. I have seen only the live switched on several occasions, and still can't fathom why.

 

[Qedelec]

And what happens if the DNO connect Live and Neutral reversed. Live would still be connected even with the installation 'Isolated'

Personally I would not be happy with just live interupted. There is a requirement to use a double pole swith in the CU.

 

[plugwash]

yet your happy with just the live disconnected by pulling the service fuse or switching off a MCB (does anyone really turn off the entire install?!)

afaict in this country the recs are incrediablly carefull to avoid P-N reversal especially because there are people with thier earthing systems connected to the neutral.

The requirement for a DP main switch on most single phase installs (iirc you don't need it if you restrict access to the switch to suitably competent persons but i don't remember the details) is from BS7671 which isn't law and i'm pretty sure isn't what the recs work too.