Interchangeable MCB'S RCD'S Etc ( What Fits? )

[phil d]

3 actually, use an existing circuit. Either a 6A circuit to connect the lights to directly, a <32A circuit and connect a switch fuse or find a spare circuit (or make one) and stick another board as a sub off the existing.

True, but I was thinking of an absolute worst case scenario, where your option wasn't possible.lol

 

[Sidewinder]

The issue that exists is that this problem has been recognised by the "powers that be", and formal guidance published in the way of a British Standard explaining what needs to be done to comply with the safety requirements of the enclosure.assembly after the alternative parts have been fitted.

This is detailed in:

BS 6423:2014, Code of practice for maintenance of low-voltage switchgear and controlgear. (£190.00 / 44 pgs)

The BS EN 61439 series of standards are heavily referenced within this standard, and, the requirements of this series are the prime requirement.

So, if you are substituting without considering the requirements of this standard and being able to justify this, then, if, something goes wrong, questions would be asked as to why the standard was not followed, and to justify how you can prove that your solution is just as safe.

Which is going to be difficult by this time, as there is already an issue with your solution, and, you had not followed the accepted published industry guidance on the process.

 

[steptoe]

a LOT depends on the circumstances,

I done a job last week where I noticed a 1mm cable had been terminated from a 16A MCB, not having the correct make of MCB with me I fitted an alternative 6A that was a physical match, I feel I have left the install safer than it was before I visited.

 

[Sidewinder]

a LOT depends on the circumstances,

I done a job last week where I noticed a 1mm cable had been terminated from a 16A MCB, not having the correct make of MCB with me I fitted an alternative 6A that was a physical match, I feel I have left the install safer than it was before I visited.

In one way, definitely, in others, perhaps not?

IF, the correct MCB is still available from the board, and it goes pear shaped, you will be expected to prove how what you did was as safe as fitting the correct MCB, if, it wasn't available, you will be expected to explain how you validated the fitting of the MCB you did.

I don't like it, just like I don't like the idea of the 18th, and I have made my voice known, along with what I have heard of the content, but, one solitary Engineer protesting against things, gets nothing changed.

 

[steptoe]

In one way, definitely, in others, perhaps not?

IF, the correct MCB is still available from the board, and it goes pear shaped, you will be expected to prove how what you did was as safe as fitting the correct MCB, if, it wasn't available, you will be expected to explain how you validated the fitting of the MCB you did.

I don't like it, just like I don't like the idea of the 18th, and I have made my voice known, along with what I have heard of the content, but, one solitary Engineer protesting against things, gets nothing changed.

devils advocate

should I have disconnected the lighting circuit and left the lady with no lights in her house?

surely that would have been a dangerous act?

and,

to leave the circuit connected to an obviously oversized OCPD  would have been an equally dangerous act,  ?

I know that I feel what I done was the right thing to do, whether actually correct and proper in the regs,  down to interpetation imho,

 

[Lurch]

I know that I feel what I done was the right thing to do, whether actually correct and proper in the regs,  down to interpetation imho,

Pretty much the correct response to most regulations. Most of our work nowadays is arse covering and blindly following loose rules, no-one thinks about what they are doing and why, and why the regulations are there.

 

[Doc Hudson]

to anyone's knowledge have there been any proven catastrophic system failures, due to mixed brands within an enclosure, that have resulted in any individual or business being successfully prosecuted? I am assuming any instance since May 2009 would have already been linked or referenced in this thread?

Doc H.

 

[SBS Dave]

Hi Doc,

There have been many dire warnings from BEAMA regarding Mix & Match, but I don't recall them ever giving an example of system problems, let alone prosecutions.

BEAMA coined the phrase Mix & Match to describe bad practice in their view, but they didn't think it through and they really meant Mix & Mismatch.

No electrician would deliberately mismatch equipment, but physically compatible devices to the required standards, IMHO, can be and are used in situations where there are no viable alternatives. This is where the professional electrician considers risk assessment and works within his interpretation of the relevant Regulations. This is MIX & MATCH, the operative word being "match".

Last year, after many years battling this subject, I put down my thoughts in relation to my Compact RCBOS, but most of the points are valid with respect to MCBs or any other Consumer Unit device.  I attach it for the Forum's consideration.

SBS Dave 

 

[SBS Dave]

Don't know where the file went, but here it is again

 

[Evans Electric]

I can confirm that the MCBs used in the Memera 2000  consumers ( quite common in this area)  are EXACTLTY the same as  the Bill Talisman / MEM /Eaton range of breaker .

The only difference is the part number ...which , when you think about it , is ludicrous . 

Now surely if you retrofit one of those into a Memera 2000  you won't end up in the Old Bailey for invalidating the BS of the board with them all coming from the same factory. 

My wholesaler insists that many MCBs come from 1 of 2 factories in Europe , badged up in many guises .

 

[kerching]

I can confirm that the MCBs used in the Memera 2000  consumers ( quite common in this area)  are EXACTLTY the same as  the Bill Talisman / MEM range of breaker .

The only difference is the part number ...which , when you think about it , is ludicrous . 

Same with the BILL/MEM MCCBS

TLGs.  Are same as MGLs...

same throughout the whole range

and since they discontinued the range some are as rare as Rocking Horse Faeces and cost serious money.

 

[Evans Electric]

Yep,  just had a 50A MEM   on ebay for £10 .

 

[Andy™]

now if only there was something that would fit a QOE...

 

[Evans Electric]

Looks like Schneider are making them Andy  .   

There are a few rogue MCBs  that stand alone ...just to anoy us :-

Federal Electric

Square D  QOE

Crabtree C50

 

[ProDave]

I have never had a problem finding QOE mcb's on ebay, but I keep a few anyway as an industrial unit I look after uses them.

Back to Memera2000. Wylex mcb's / rcbo's are a perfect fit, unless you find a MEM2000 with the wide fingered busbar (then there is always a file) :run  

 

[steptoe]

I have never had a problem finding QOE mcb's on ebay, but I keep a few anyway as an industrial unit I look after uses them.

Back to Memera2000. Wylex mcb's / rcbo's are a perfect fit, unless you find a MEM2000 with the wide fingered busbar (then there is always a file) :run  

Aren't they the memshield2 boards Dave,?

I didn't have that issue of the wide fingers on the last one I did, maybe the busbar faeries had been there before me,   :innocent

 

[kerching]

now if only there was something that would fit a QOE...

QOE?...is that the one with the two U shaped clips?.....one for the fixing rail and one for the busbar?

if so then I have a fair number of them along with a load of TP type4/X ones.......I feel,an eBay moment coming on

 

[Mike Mckay]

now if only there was something that would fit a QOE...

With the QOE ones though, if its a replacement just get any standard MCB, remove the clip part from the one being replaced and attach it to the new standard MCB

Its only an issue if youre adding an extra MCB rather than replacing a faulty one

Once I realised what an oddball they were I just started keeping the additional bit with the clips on whenever I removed one of them

What should really have happened though if the British standards institute was actually doing the job it was being paid for would have been for one of the safer systems like the crabtree shielded busbar system to have been made the british standard, same too with the pendant fittings that remove power from the pins when the bulb is removed

When a product is clearly superior to anything else on the market the BSI "should" be all over it pushing for it to become the standard and the only one persmissable even as far as things like fixed screw hole locations for conductors on sockets for greater compatibility when someone has cut the wires short so that any socket will fit thereafter

 

[Andy™]

Looks like Schneider are making them Andy  .   

There are a few rogue MCBs  that stand alone ...just to anoy us :-

Federal Electric

Square D  QOE

Crabtree C50

nope. schneider make the KQ's which are identical to the square D KQ's, but the older QOE can only be got on ebay

another regional thing, federal electric boards are very rare up here too. dont find many C50's either

 

[Evans Electric]

What should really have happened though if the British standards institute was actually doing the job it was being paid for would have been for one of the safer systems like the crabtree shielded busbar system to have been made the british standard, same too with the pendant fittings that remove power from the pins when the bulb is removed

I'd second that .  But it does seem that what is important to us is'nt  the same to the establishment . 

All this about not using another make in a board can cost you a lot of time & money .  I agree that it looks like a codge but in the real world  if the MCB is made to , say , BS 60898 , whats not to like when you cannot source the same make ?

I remember many years ago,  the NICEIC man said he was at a cable manufacturer's conference  the next day ...I said .. can you persuade them to drop the new  diabolical  , solid strand 2.5  T&E  7 return to stranded .

He said why would you think they'd listen to your complaints .          ( That was a statement that changed my attitude at a stroke)