Merlin Gerin 30ma 2 pole RCD MULTI 9 Range, TRIPS (oversensitive?)

[Andyrc]

Hello People, Im completing a "SMALL" Commercial Job, and The SUB main is Controlled by a Merlin Gerin 100amp/30ma RCCB, Single phase,2 pole ( DB is 6 WAY) The New Install is on a TT, as it's out of the Equalpotential Zone, When performing tests, the 30ma RCD(main switch) at the sub main Trips! and not the "local" RCD in the new SPLIT load board, So I am thinking? change, the MAIN supply RCCB for a 100amp/100ma , and then change the MCB's at the the same Board, for 30ma RCBO's where Needed! as some supply "local" sockets in the same Building! ............The other thing is, Now that MERLIN is now SCHNEIDER Electrical,of course just a Diff name, wether a MK 6004s RCCB would be Compatible (costs etc) as looking on line, they look the SAME, .......(SO a 6way DB 100amp/100ma RCD Mainswitch, supplys all the other DB,s Variuos out buildings etc, and my SPLIT Load TT board is supplied from that) also as I live in Cornwall it's a you know what to get hold of things, Cheers People, Andy

 

[Deleted member 9648]

Think you've answered your own question...a 30ma RCd mainswitch will always be problematical....your solution sounds good,but the 100ma will need to be time delayed or it will still trip on a 5x test.

 

[Andyrc]

RCCB 100AMP/100MA "S" TYPE ARRIVED, from YORK all the way down to Cambourne, Cornwall, over nighter, as EDDY'S had NOTHING between here and there, COST £147!!!!!!!!! over 350 miles! CRAZY!!!!!