triple pole breaker for a single phase supply

[washayag]

When doing Inspection and Testing for a CoC for a domestic Installation for a house that used to have a three phase supply now with single phase through a TP MCB. is this legal and what Reg can I use to support this.

[Dave A]

What you need to pay attention to in particular is 6.9.2.2.

With a 3 phase installation, the disconnecting device need not disconnect the neutral in a TN system.
With a single phase system, both the live and neutral must be disconnected.

[washayag]

Well that is a good point. Thanks Dave A

[AndyD]

What you need to pay attention to in particular is 6.9.2.2.

With a 3 phase installation, the disconnecting device need not disconnect the neutral in a TN system.
With a single phase system, both the live and neutral must be disconnected.

Would the regs forbid using a t/pole MCB to do this?

[washayag]

I haven't seen anywhere in the regs where it specifies that you cannot use a TP for a single phase, but in most cases you find that, most sparkies would not consider protection of the cable etc.