I have posted a piece here which is also on the TT topic, but is more general and I think a new thread would be better. Your voice is heard. See below.
For what it is worth, the new Wylex 'NM range' CU I had my head in this weekend came with a leaflet that has no such caution - just a note that 'All RCDs must be used in conjunction with a 50A max rating B or C type MCB.'
Which apart from the rather "translated German" word order, and seemingly precluding the plurality of MCBs normally seen supplied by one RCD, does not say anything about total loads, or indeed the rating of the incoming supply fuse. Unless of course it was supposed to mean the incoming protection should be a 50A MCB, but it does not say that, clearly. Now I have fished it out of the bin bag, I can post a picture of the leaflet later on tonight if that helps, though the instruction leaflet is copyright 2012 so there may be a newer version coming soon, if this is the old one- I have no idea how long this CU sat on the wholesalers shelf before I got it.
As it happens I am fitting the version that is a dual tarriff all RCBO board, as it is my own, and that approach appeals both to my engineering judgement.and SHMBO, but the instruction leaflet seems to be universal.
For what it is worth, the new Wylex 'NM range' CU I had my head in this weekend came with a leaflet that has no such caution - just a note that 'All RCDs must be used in conjunction with a 50A max rating B or C type MCB.'
Which apart from the rather "translated German" word order, and seemingly precluding the plurality of MCBs normally seen supplied by one RCD, does not say anything about total loads, or indeed the rating of the incoming supply fuse. Unless of course it was supposed to mean the incoming protection should be a 50A MCB, but it does not say that, clearly. Now I have fished it out of the bin bag, I can post a picture of the leaflet later on tonight if that helps, though the instruction leaflet is copyright 2012 so there may be a newer version coming soon, if this is the old one- I have no idea how long this CU sat on the wholesalers shelf before I got it.
As it happens I am fitting the version that is a dual tarriff all RCBO board, as it is my own, and that approach appeals both to my engineering judgement.and SHMBO, but the instruction leaflet seems to be universal.
