Replacing Isolating Switch With Rcd To Split Load Consumer Unit

[lyserman]

I have been asked to change a cu because only one half of the load is protected by rcd.

There is an isolating switch (60947) fitted in the tails from the cutout feeding the cu.

Is there anything wrong in replacing the isolating switch with an rcd type?

I understand that any fault will now switch the whole house supply off but it would be a simpler solution and there is nothing intrinsically wrong with the existing cu.

Thanks for any input.

Tony

 

[sellers]

yes, it is an issue due to the inconvenience.

You could install RCBO's for the unprotected circuits. or you could just change the CU.

 

[betty swollocks]

Without going to the van I'm sure reg 314 states that to reduce hazards and to minimise inconvenience in the event of a fault and to reduce unwanted tripping due to excessive protective conductor currents an installation should not be connected to a single rcd which is what you are proposing, I can't think of a reg to say you couldn't replace the existing consumer unit main switch with another rcd (making two- like a17th edition cu but without a main isolator) seeing as you already have that main switch connected to the tails after the meter to isolate the whole installation when required, but I think RCBO's is the way I would tackle it

 

[ProDave]

Another vote for just fitting rcbo's to the unprotected circuits. Far simpler and better solution. 

 

[Evans Electric]

Don't fit an overall RCD Lyserman , bad idea.  Most of the modern boards  can be configured to dual RCD .  Did it with a Wylex last week , 16th type Split load to a dual RCD .

Or as said ,fit RCBOs . 

Edit:   Doubtless I'll be told you can't alter consumer units , personally I can't see the problem with an existing Wylex enclosure, adding a Wylex device and altering the Wylex busbar to suit .  Which is what you do anyway when configuring the board to your needs.  

 

[lyserman]

Thanks for the thoughts.

My initial reaction has been confrmed. It was someone else's cost cutting thoughts that made me ask the original question.

There is not enough room to add an rcd without removing the main isolator so it will be RCBOs or a new cu.

Due to the cost, I can see it being a new cu as a fully loaded 10 way dual rcd is less than the cost of RCBOs would be.

Tony

 

[SLIPSHOD & SLAPDASH]

A BG board from Screwups costs £45. 1 Wylex RCBO costs £30 but how long will it a new board compared with swapping a few RCBO's