CU Replacement on old TT system

[Vessy]

Hi all, first post for me, been a brouser of this site and all it's great info for years.

Looking to replace an old (fuse wire) CU in a 70's house, overhead cables and TT setup. There is a Chilton ELCB installed in the meter tails to the existing CU, the unit is a Type-E 60A 500ma ELCB (Black Unit), no earth connection just the two meter tails in and two out. Will be installing a split load unit comprising of 100A main switch feeding 1 83A 30ma RCB feed and 1 60A 30ma RCB feed, plus relevent MCB's.

Should I leave the old ELCB in place or ditch this as I will have all circuits covered by 30ma RCB's?

The unit works, just doesn't offer me anything above the protection in the CU. Not planning to have any MCB's before the RCB's.

Thanks.

 

[telectrix]

no need for the 100mA RCD. that used to be fitted on TT systems, but is now redundant when fitting 30mA RCD to all circuits.

 

[mickytuff]

remember, dedicated smoke alarm circuits are not to be on a rcd, just incase this is present in your situation bud.

 

[Will David]

Thanks chaps, most helpful.

 

[IQ Electrical]

Purely for information, the obsolete Voltage Operated Earth Leakage Circuit Breakers mostly (but not always) have a yellow test button and (always) have a terminal labelled 'F' or 'Frame'.

 

[IQ Electrical]

Double posted