RCBO friendly CU re clearance (merlin gerin 1-mod)

[Dorothy Bradbury]

I have a "new style" MK CU with several MG RCBOs.

During installation I noted the space above the RCBOs is somewhat limited - fine for MCBs, very tight for # RCBOs.

Q: Anyone "been here & found a CU with more space"?

I suspect a more industrial unit - but space is limited.

Thanks.

[Andrew Gabriel]

I hadn't noticed the difference before, but you're right, the newer MK CU's have less clearence between the rail and top than the previous CU's with the clear plastic covers (which were much better quality IMHO). I have one of each here, and the older one does have a couple of the MK rebadged MG RCBOs in it, but it's a bit of a pain as they need DIN rail adaptors to raise them to the correct front panel height and bus bar adaptors as they don't accept the MK bus bar directly. The current MK single way RCBO's are about half an inch shorter, and don't need the DIN rail or bus bar adaptors.

You could use a current RCBO, but I guess you already have the MG ones, and the current ones are not available in all the same ratings the earlier MG rebadged ones were.

For industrial CU's, I use the MEM memshield 500 (IIRC) range. (I think MEM recently changed its name to Eaton or something like that). I like the way you can make up RCBO's by adding an RCBO pod to their MCB's to get an RCBO of any rating (although the 10mA RCBO's are only available preassembled). However, these CU's won't take MK parts -- bus bar is different style. They also do a downrated residential range but I've never used that.

[Dorothy Bradbury]

Yes they were - albeit more expensive.

That is handy re upgrade/migration path.

I wonder if the bus bar difference can be avoided... o Move isolator, rcd, split-load-cabling, busbar, RCBOs from old unit o Adjust the DIN rail to cover plate distance if needed

Could be the DIN plate isn't in the correct place...

I'm thinking of the French CU which have enough space in them to get the average estate agent excited in terms of sub-letting. An issue there may be the positioning of N & E bars re plain distance.

Thanks.

[Andrew Gabriel]

Yes, but I buy MK on quality, not price, so that was expected.

I don't think they use a top-hat DIN rail. I don't have one handy to look in, but I suspect it has an assymetric DIN rail which only holds the top of the breaker, as the bus bar holds the bottom.

[Dorothy Bradbury]

Ah. Noted, will wait until the next renovation :-)

Thanks.

[John Rumm]

The Contactum range from TLC have a fair bit of clearance. Piccie here:-

[Christian McArdle]

Yes, I used one. Loads of room for RCBOs and all sorts in there. No problem with a mixture of top and bottom entry, either. The RCBOs tend to be double width, which is not a problem for me as they do large consumer units, single width RCBOs often claim they must have a blank space beside them anyway, and it makes the wiring less congested.

Christian.

[John Rumm]

IIRC TLC do a range of single width RCBOs (only available in their "extended range" on the web) that run without needing the extra space.