Is it possible to put a 16mm swa on a 40a mcb protected by an rcd

[JayBowen]

Is it possible to put a 16mm swa on a 40a mcb protected by an rcd

 

[M4SSO]

Is it possible to put a 16mm swa on a 40a mcb protected by an rcd

If you look at the technical information from the MCB manufacturers website you should be able to obtain the maximum cable size that the device can accommodate, I think a typical 40A mcb will accept a 25mm cable but you need to check this. You will also need to check that the neutral and earth conductors can also safely be accommodated n their respective terminals. The issue normally with larger SWA cables is having sufficient space in the enclosure to gland and terminate the cable.

 

[MDJ]

Is it possible to put a 16mm swa on a 40a mcb protected by an rcd

why would you think it may not be okay

 

[Darkwood]

Cable calcs define your answer, is it 3m long or 300 hundred if you get my drift, your query is lacking context as to why you ask, if its simply terminal entry size then yes the mcb should accommodate a 16mm.

 

[DefyG]

Or are you asking as it is SWA, and you may think a RCD is not required due to the SWA being earthed ?

It can be or certainly may be necessary/advisable depending on the connected load.

 

[simpson93]

It's possible

 

[buzzlightyear]

Is it possible to put a 16mm swa on a 40a mcb protected by an rcd

OK, what is it feeding load wise.

 

[JayBowen]

Its going to be feeding 2 ring circuits,2 lighting and 1 32a commando. The 2 ring circuits will never be running at the same time. The run will be about 11m and will be going on a 63a split rcd board.

 

[DefyG]

and will be going on a 63a split rcd board.

You wont be needing the upstream RCD as well then will you?

 

[JayBowen]

It will just be rcd protected at the incoming point and then mcbs at the other end

 

[brianmoooore]

It will just be rcd protected at the incoming point and then mcbs at the other end

Poor design. SWA doesn't need protection by a RCD, since there's very little likelihood of making contact with the live conductor, without shorting it to earth, in which case the OCD will take care of things.
Ideally this should be a fuse rather than a MCB, to provide discrimination between it and the MCBs or RCBOs at the load end.

 

[timhoward]

Additionally, it would be better if a fault on the circuits the far end didn’t take out half the house too.