Need to switch neutral for single phase domestic DB

[Powerhouseelec]

Hello, I was doing a job today connecting up the SWA I've put in to supply the electric gates. The DB is a three phase connected up as single phase. They have taken the 25 MM into the L1 of the 3 pole Main switch but the neutral goes straight to the N bar. Its a PME system. Am I right to say that it should isolate both L+N or is it expectable how it has been done?

 

[7029 dave]

common practice not have switched neutral on 3phase supply.

 

[Richard Burns]

I think the regulations state that for a TNCS / TNS system it is not necessary to isolate the neutral but then goes on to say that for installations not under the control of skilled or instructed persons that the neutral should be switched. (but I could have remembered wrong!)

 

[Deleted member 9648]

537.1.2 states the neutral conducor of an installation need not be isolated on a TNS/TNCS as long as it is considered to be reliably at earth potential.

 

[Darkwood]

If this is domestic or similar set-up where the switch may be operated by an ordinary person then 537.1.4 will apply and both live conductors of the single phase supply.

537.1.2. Quoted above has 2 exceptions highlighted of which the OP may be subject to but we lack info'.

 

[Powerhouseelec]

thank you all for the replies, after posting I did a bit more research and came to the same conclusion as stated above. It is a house so would need to switch the neutral.