Replacement for BS 4293 RCCB

[pauchacai]

Hi fellas. Looking at an old domestic MK board with BS 3871 CBs. Standard arrangement, E&B all good, TNCS. Issue is there is no 30mA protection but all circuits are fed from a 100mA BS 4293 RCCB which also acts as main switch. Not sure why unless previous TT and converted...? Problem is this fails test at 100% rated trip current. Does anyone know of a device I can use as a straight replacement or am I probably looking at updating the board if they will go for it?

cheers

 

[BlueToBits]

You could fit an external RCD and bypass / remove the existing one

 

[chrish_1977]

Agree with bluetobits, just replace the 100 with a standalone 30mA

 

[telectrix]

if the existing RCD is a delay type, don't think most MFTs will tewst it. if it is, bung it in an enclosure upfront and fit 30mA RCD as CU main switch.

 

[pauchacai]

Cheers. It's not an 'S' type device. Not sure i'm happy with covering all 7 circuits with a single 30mA RCD plus the work i'm being asked to do carries no requirement to install additional protection. I could realistically just carry out the work and note the deficient device on the cert as it still fulfills it's role as a main isolator and there is no requirement for 100mA protection on this installation, perhaps issue them a potentially dangerous condition report too. Want to do the best for them though so will try to convince them to let me correct it. Best is obviously a new board and bring it all up to standard if they will swallow it in a triple dip recession....!