Parallel sub mains

[Kilogram]

I currently have a shop which has 3 phase 6mm cable running to it but the shop is only allowed single phase, currently renovating and they need more than a 32a supply. Can I parallel 2 of the 6mm and upgrade the quicklag breaker to a 50a at the MSB and make it a 50a main switch at the shops sub board. Both are same length and ran in one orange circular. In AS3000 I cant fjnd anythjng other than me being able to ruth them in parallel as they are 4mm or above.

Running new sub mains is what I'm trying to avoid for the client

 

[James]

When you say you have a 3 phase cable, do you mean a 3 core cable?
If so, you have not got enough cores to run a parallel supply.

You would need to have 4 or possibly 5 cores.
2 cores parallel for live
2 cores parallel for neutral
Possibly 1 core for earth,

It may be possible to use a ground rod or other method of earthing but I am unsure about regulations in upside down land.