Smaller MCCB feeding larger MCCB-RCCB

[Bradley6969]

Anything wrong with this?
125Amp 4 pole MCCB from panel fed to new panel with 150mm 4 core ALI then in that new panel 250Amp MCCB/RCCB then all sub circuits?

 

[cliffed]

Maybe,back to front

 

[Pete999]

Well yes!

 

[cliffed]

Sorry trying to delete that,thinking the 250 amp should be the same as the 125

 

[Pete999]

Sorry trying to delete that,thinking the 250 amp should be the same as the 125

Or Smaller

 

[Spoon]

What installation method?

 

[Ian1981]

Is the 250 breaker/isolator just a switch disconnector to BSEN 60947-3 or is it actually a circuit breaker to BSEN 60947-2?

 

[Bradley6969]

Yeah there both MCCBs but the 125amp is just MCCB and the 250amp is MCCB-RCCB

 

[Toneyz]

What is the reason for the MCCB/RCCB? (and I am referring more to the RCCB element).

 

[BeardyJaws]

Have they used the 125a to protect the cable and then 250a for the RCD protection? I sometimes come across a 10a 60898 then a 32a 61009 separately before the first light for example.

 

[The Ghost]

Selectivity?

 

[ipf]

Am I seeing aluminium cores involved?

 

[Spoon]

Am I seeing aluminium cores involved?

I'm presuming, yes. The OP says "150mm 4 core ALI" in the first post. That is why I asked about installation method.