Rccb

[hardy sparky]

Can i use a 100A 300MA RCCB as a main switch behind RCBOs ????

 

[bigbaddave]

If you really want to. I am assuming every curcuit it protected by 30MA RCBO?

 

[Sintra]

What is your reasoning for wanting to install this 300mA device?

 

[JD6400]

What type of installation is it for ?

 

[hardy sparky]

yes of course

 

[hardy sparky]

its on a TT system

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3 phase

 

[bigbaddave]

yes of course

So what is the purpose of the 300ma if you dont mind us asking

 

[hardy sparky]

well its on a 3phase TT system with one supply board and to consumer units, access to supply board is restricted

 

[JD6400]

You will probably find that a 100ma s type will be a shed load cheaper to buy than a 300ma ( Thats what i have found in the past anyway ! ) , and unless they are planning to install air / ground source heating or inverter drives then i can not think why it needs to be 300ma ?
You may want to think about going for a stand alone one in its own enclosure as well , as not all boards have them available as a extra option .