As per the subject, if one mixes MCBs and/or RCBOs of different makes in a consumer unit is it likely to stop it conforming to IEE rules?
Also I presume the new (18th edition) rules regarding flammability of CUs would only apply if one replaces a CU and are not retrospective. Adding or changing MCBs to RCBOs in an existing CU wouldn't require that the CU be upgraded to 'non flammable'.
Assuming they are mechanically compatible, then there is no real practical problem. The resulting setup may not meet type approval any more, but I can't see that being a issue.
Correct.
Yup, if you install a whole new CU then it needs to be to current standards. No requirement to change what is there.
Thanks John, just what I needed.
I'd be a little perturbed that CUs were even made that easily caught fire at any time in history myself. Seems a little counter intuitive to me. Brian
Its not so much that they catch fire, but more they are unable to contain one inside the CU. Even plastic CUs are required to be made from a self extinguishing material.
They don't easily catch fire. They catch fire more since the requirement to fit active bits like RCDs as they are more likely to overheat than a plain fuse.
The cause of catching fire was entirely poor workmanship by electricians
- not doing up the terminal screws tightly enough (or at all in some cases). It was well researched, because it started becoming a significant problem in new installations. It wasn't failure or ageing of any of the internal components.
It's now on the 18th edition EICRs that the person doing the testing has to check the tightness of the bus bar connections and check that the bus bar to the bottom of the MCBs is actually inside the MCB clamp.
Here is one I found last year.
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