Hi All
Ok...after many years of testing rcd trip times...having some failed or faulty rcd's....we are starting to come across perfectly good rcds / rcbo's . .from various makes....that wont trip at all..or wont trip in under 40 m/s.
about a year ago...in a domestic property..we fitted a new dual rcd c/u . ..1 rcd refused to trip either with test button or tester...we swaped the 2 over...now the other one wouldnt trip....
in the end we found a pressure fault between n - e at a spur we didnt know existed (it ran an old back boiler pump)....we informed the niceic of this via the help line and were advised we should contact the maker of the rcd as it seemed a n - e fault was holding the rcd on rather than making it operate...odd....
now this week in an industrial / commecial unit..we have discovered that rcbo's covering 13A socket outlets around the building..in both offices and the shop floor are failing to operate either at all or well over 40m/s even at x5.
in the same week...we found an exisitng rcd in another domestic that failed to operate if the boiler spur (which was covered by this rcd in a dual rcd board) was switched on....external boiler..less than 5 years old....brand new controler....
switch the spur off...and all is good.... (this house does have a pv circuit...but it was switched off and both ac and dc isolators were also off)
Now i understand that DC being leaked onto a circuit can cause and rcd to not operate...
ive checked with some wholesalers...and type A or type B rcd's are seemingly hardly ever fitted....mk are making theirs obselete...though hager are listing a type A ... well over £100 ...
My question is really ...HOW IS EVERONE GETTING THESE RCD'S / RCBO'S TO COMPLY WITH THE 40M/S STANDARD..??
no one is fitting the type A or type B ones ....and more and more inverters are being fitted to stuff these days...even in some washing machines now...not just pv and motor speed controls....im assuming this is the cause...
but the question is what do we do about it...how do we get these to comply....or do we not bother..and just note down the failure in our observations...and deviations from 7671...?
is this the begining of the end for rcd protection..?....
in some tt systems i work on...where the rcd is almost total protection...what happens when it wont operate..?
all thoughts greatfully accepted
cheers
vitoboy
Ok...after many years of testing rcd trip times...having some failed or faulty rcd's....we are starting to come across perfectly good rcds / rcbo's . .from various makes....that wont trip at all..or wont trip in under 40 m/s.
about a year ago...in a domestic property..we fitted a new dual rcd c/u . ..1 rcd refused to trip either with test button or tester...we swaped the 2 over...now the other one wouldnt trip....
in the end we found a pressure fault between n - e at a spur we didnt know existed (it ran an old back boiler pump)....we informed the niceic of this via the help line and were advised we should contact the maker of the rcd as it seemed a n - e fault was holding the rcd on rather than making it operate...odd....
now this week in an industrial / commecial unit..we have discovered that rcbo's covering 13A socket outlets around the building..in both offices and the shop floor are failing to operate either at all or well over 40m/s even at x5.
in the same week...we found an exisitng rcd in another domestic that failed to operate if the boiler spur (which was covered by this rcd in a dual rcd board) was switched on....external boiler..less than 5 years old....brand new controler....
switch the spur off...and all is good.... (this house does have a pv circuit...but it was switched off and both ac and dc isolators were also off)
Now i understand that DC being leaked onto a circuit can cause and rcd to not operate...
ive checked with some wholesalers...and type A or type B rcd's are seemingly hardly ever fitted....mk are making theirs obselete...though hager are listing a type A ... well over £100 ...
My question is really ...HOW IS EVERONE GETTING THESE RCD'S / RCBO'S TO COMPLY WITH THE 40M/S STANDARD..??
no one is fitting the type A or type B ones ....and more and more inverters are being fitted to stuff these days...even in some washing machines now...not just pv and motor speed controls....im assuming this is the cause...
but the question is what do we do about it...how do we get these to comply....or do we not bother..and just note down the failure in our observations...and deviations from 7671...?
is this the begining of the end for rcd protection..?....
in some tt systems i work on...where the rcd is almost total protection...what happens when it wont operate..?
all thoughts greatfully accepted
cheers
vitoboy