What type of circuit breaker would be used for a three phase circuit?

[Robert2254]

well doesn't that circuit need to be protected like all the other circuits which are all rcbos so I thought it would be best for this to be a rcbo instead of a 3P+N MCB with a RCD. But am I right to use a 3P+N breaker for 3 phase though ?

only need an RCD device if you are supplying the equipment through a socket. Otherwise it's just a triple pole mcb and neutral isn't switched.

 

[wsoppitt]

So guys , for example supply to 3phase roller shutter door motor with attached 1m lead , if socket was high level ( say 3.5m up ) controlled by low level isolator, would you still put it through an rcd ?

 

[westward10]

So guys , for example supply to 3phase roller shutter door motor with attached 1m lead , if socket was high level ( say 3.5m up ) controlled by low level isolator, would you still put it through an rcd ?

Yes.

 

[davesparks]

only need an RCD device if you are supplying the equipment through a socket. Otherwise it's just a triple pole mcb and neutral isn't switched.

This is incorrect, there are many reasons why an RCD may be required.
There is not enough information in the OP to make this decision.

 

[davesparks]

So guys , for example supply to 3phase roller shutter door motor with attached 1m lead , if socket was high level ( say 3.5m up ) controlled by low level isolator, would you still put it through an rcd ?

There is no exception for height or accessibility in the regulations.

The designer of the installation may do a risk assessment to justify not providing RCD protection if there is some reason why RCD protection may be undesirable.

 

[Vortigern]

I think the above is a good nudge for you to consider carefully. Medical supplies kept in fridges at surgeries, would you RCD that circuit?

 

[davesparks]

I think the above is a good nudge for you to consider carefully. Medical supplies kept in fridges at surgeries, would you RCD that circuit?

Yes, but i'd put them on their own dedicated circuit.

 

[Flanders]

You will need to now if there is start up current on the equipment. To choose what type of mcb / rcbo B C or D .Also Just wondering if 16amp ocpd is a bit close to the limit if the equipment demand load is also 16amps.