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Another question!
I'm designing for a TT system, there's going to be one 10 way Rcbo consumer unit for the house, less than 3 metres away from the DNO cutout, I'm going to swap the main switch with a 100ma Stype rcd to provide fault protection ( I'll be fitting a tails clamp inside the CU and a tails gland on entry into the CU so there is very little risk of a fault but cost is not an problem so I'd rather fit it).
However, there is another consumer unit in a garage about 10metres away, my plan is to run an SWA in to this new board, obviously being TT it will be highly unlikely to meet the Zs values to allow the fault current to blow the fuse, therefore no fault protection. The fault protection will be in the way of another 100ma s type rcd installed next to the house consumer unit.
My question; with it being over 3metres away, should I install a 100ma s type rcd AND an appropriate sized switch fuse? The fault current will never get to the point to blow the fuse but I suppose I'll have to cover overload issues with it (no issue of overload either really).
(I was just going to install a 4 way unit, 2 ways for the 100ma s type and 2 for the switch fuse).
A question regarding the earth rods aswell, although the submain cable run length is about 10metres the earth rods would only be about 3metres apart once installed. Would it be wise to install one earth rod and have the garage consumer unit run off the same earth as the house, or should I install an earth rod each? And maybe even link them?
I am terrible for writing questions and making it clear so I hope you all understand the above.
Cheers
I'm designing for a TT system, there's going to be one 10 way Rcbo consumer unit for the house, less than 3 metres away from the DNO cutout, I'm going to swap the main switch with a 100ma Stype rcd to provide fault protection ( I'll be fitting a tails clamp inside the CU and a tails gland on entry into the CU so there is very little risk of a fault but cost is not an problem so I'd rather fit it).
However, there is another consumer unit in a garage about 10metres away, my plan is to run an SWA in to this new board, obviously being TT it will be highly unlikely to meet the Zs values to allow the fault current to blow the fuse, therefore no fault protection. The fault protection will be in the way of another 100ma s type rcd installed next to the house consumer unit.
My question; with it being over 3metres away, should I install a 100ma s type rcd AND an appropriate sized switch fuse? The fault current will never get to the point to blow the fuse but I suppose I'll have to cover overload issues with it (no issue of overload either really).
(I was just going to install a 4 way unit, 2 ways for the 100ma s type and 2 for the switch fuse).
A question regarding the earth rods aswell, although the submain cable run length is about 10metres the earth rods would only be about 3metres apart once installed. Would it be wise to install one earth rod and have the garage consumer unit run off the same earth as the house, or should I install an earth rod each? And maybe even link them?
I am terrible for writing questions and making it clear so I hope you all understand the above.
Cheers
