2 main switches?

[andypandy]

A fuseboard I was looking at has a spare way, but it is not rated up to 40A, only 30A,so I was going to replace the board. I contacted a website and they told me that instead of replacing it I could add a shower unit (containing a 30mA RCD and a 40A MCB) if there was a separate main switch. The cables supplied with the shower unit are 10mm tails. What size should the earth be?

 

[il78]

Your saying you have a spare 30A MCB in your consumer unit, what size shower are you installing and what size cable do you have......

 

[andypandy]

10mm ft+e and the shower is 9.5kW.

 

[il78]

Would it not be easier & cheaper for you to purchase a new 40A MCB for your consumer unit..........

 

[andypandy]

The MEM Memera board that has the spare way has rewireable fuse ways that are only rated up to 30A. The Memera board that has a fuse way up to 40A has a fuseway separate to the main bank of fuses, and mine is not that type.

 

[il78]

No problem.....

Firstly are you confident to install the shower unit at the mains area? (dont take offence if you are).

What size meter loops are in at the consumer unit now? You are looking at getting the same for the shower unit. (Half this to give a size of earth, ie 25mm loops - 16mm earth)

Is there a main switch installed to isolate the meter loops so 100A (Henly) blocks can be installed to split the loops.....

This is my own opinion and what I recommend and personally would not install the 10mm loops supplied.

 

[andypandy]

meter loops are 25mm. earth is 16mm

 

[paulh53]

meter loops are 25mm. earth is 16mm

"Meter Loops"?

Meter Tails Of 25mm2 PVC Insulated/PVC Sheathed Are Ok For 80/100a Supply For Domestic Premises
Main Earthing Conductor Of 16mm2 Is Also Ok For The Above,