MCB / CU compatibility?

[HDRW]

I thought that modern Consumer Units with DIN rails were designed to some sort of standard measurements, so you could use any MCB in any CU. However...

I have a Proteus split load CU with Proteus Incomer and RCD, and DETA MCBs. This CU has only the top half of the DIN rail - where the bottom part should be is flat, and the bus-bar forms the mounting for the bottom part of the MCBs.

Looking to add another circuit (a job I started last year, naturally ) I have looked at various makes of MCB and most of them don't fit! Wylex looks like it may be OK, but MK, MEM and Merlin-Gerin seem to have too little clearance for the busbar at the bottom, making the MCB sit too high, with the "island" with the switch on it too high up to go through the slot in the lid of the CU.

Added to which some MCBs have the fixed part of the DIN clip at the top, others at the bottom, which means the location on the top half of the DIN rail can be a bit unconvincing.

I've also noticed that RCBOs vary in design, with some having the RCD section added at the top of the unit, others at the bottom (so these can't be used with a bus-bar).

Now I have little experience with modern CUs, so should I stick to using all components from the same manufacturer? (Seems to negate the point of the DIN "standard"!)

Or is there any "common knowledge" which says that Brand X is tolerant of others' parts, Brand Y only really works with their own parts, and so on?

I'm not terribly impressed with the Proteus CU, so I may change it if there's a better made, more tolerant make, and I'm open to suggestions!

Cheers,

Howard

 

[kai]

You cannot safely mix different makes of parts in the same CU. for the reasons you describe, and the risk of fire from poor contact. stick to the same make throughout your install.
The "DIN standard" was one of those that was never thought out properly!

 

[ban-all-sheds]

I thought that modern Consumer Units with DIN rails were designed to some sort of standard measurements,

Only the DIN rail itself is standard

so you could use any MCB in any CU.

The manufacturers don't want you to do that.

I have a Proteus split load CU with Proteus Incomer and RCD, and DETA MCBs. This CU has only the top half of the DIN rail - where the bottom part should be is flat,

Then it isn't a DIN rail...

Looking to add another circuit (a job I started last year, naturally ) I have looked at various makes of MCB and most of them don't fit!

That's because most are DIN rail mount items, and you don't have a DIN rail.

Wylex looks like it may be OK, but MK, MEM and Merlin-Gerin seem to have too little clearance for the busbar at the bottom, making the MCB sit too high, with the "island" with the switch on it too high up to go through the slot in the lid of the CU.

The DIN standard only defines the size and profile of the rail, not the items which mount on it.

Added to which some MCBs have the fixed part of the DIN clip at the top, others at the bottom, which means the location on the top half of the DIN rail can be a bit unconvincing.

The DIN standard only defines the size and profile of the rail, not where the clip is on the items which mount on it.

I've also noticed that RCBOs vary in design, with some having the RCD section added at the top of the unit, others at the bottom (so these can't be used with a bus-bar).

That's because these aspects are not covered by the DIN rail standard, and manufacturers don't want you to use their competitors' products in their boards.

Now I have little experience with modern CUs, so should I stick to using all components from the same manufacturer? (Seems to negate the point of the DIN "standard"!)

Same manufacturer makes life much simpler. It does not negate the point of the DIN standard, as the DIN standard only defines the size and profile of the rail.

Or is there any "common knowledge" which says that Brand X is tolerant of others' parts, Brand Y only really works with their own parts, and so on?

There may well be a set of brands whose products are similar enough to mix'n'match, but why would you want to, unless you had a really bizarre combination of requirements, in which case you should approach a professional panel builder for assistance.

I'm not terribly impressed with the Proteus CU, so I may change it if there's a better made, more tolerant make, and I'm open to suggestions!

Different people have their favourites, but as a whole the common consumer brands (Proteus, Wylex, Volex, MK) tend to be towards the bottom of the lists, and Hager, Telemecanique, Merlin-Gerin, Siemens tend to be nearer the top.

 

[Scoby_Beasley]

Different people have their favourites, but as a whole the common consumer brands (Proteus, Wylex, Volex, MK) tend to be towards the bottom of the lists, and Hager, Telemecanique, Merlin-Gerin, Siemens tend to be nearer the top.

That frightens me ban as I've always been an "MK", "Crabtree"< "wylex " fan and now you're telling me they're crap. !! HELP !!

 

[plugwash]

from what i gather mk is kinda the best of the consumer brands but thier recent boards are kinda flimsy.

the other brands ban mentioned are generally considered higher quality but aren't eften seen domestically (presumablly because of price issues).

 

[Lectrician]

I hate MK and the other crap listed above as low end.

MEM is good kit.

I also use Merlin and Square D (although square D has those crap push in prongs for the busbar.)

 

[theshogun]

I hate MK and the other rubbish listed above as low end.

I also use Merlin and Square D (although square D has those rubbish push in prongs for the busbar.)

The MCB'S above are all the same , the prongs once removed from a squareD MCB (flip the top off and unscrew them) leave same profile MCB, the only difference i can find is in the cost. Probably come out of same factory

With regards the cu's, depends i find on what make you are replacing or if fitting from new.

 

[supersparks]

mk, flimsy recently, dont fit em now cos of it, possibly the best looking though if fitted throughout, although mem has one there aswell....

top makes im my book are hager, mem and probrably square D, MK if i cant get the others or if they bring out a decent design on their switches and a CU that dosnt snap if there is a light breeze.....

and for dist boards MEM has to take it with Hager close behind