Functional testing of MCB's??

[La Poste]

It might sound a bit daft but is there any way of functionally testing MCB's?
It's easy to confirm whether an RCD is functioning correctly but is there any way of testing an MCB?
I've just been reading about counterfeit goods and how some MCB's are manufactured with absolutely no working parts inside them at all and that is what led me to asking this question.
Cheers.

 

[Engineer54]

For MCB's it isn't viable to test their operation unless your setting up to do thousands of them. With regard to counterfeiting most manufacturers have a webpage on how to spot counterfeits of their specific brands based on the actual counterfeit items they've encountered.

Far to cheap to just replace when a MCB is suspect!! Unless your dealing with obsolete MCB's, which in the main were crap, (GE/SQ D, amongst others) when they were new anyway!! lol!! Most of those CU/DB's would be better off changing, ...and cheaper in many cases!! lol!!

 

[mcb-expert]

For MCB's it isn't viable to test their operation unless your setting up to do thousands of them. With regard to counterfeiting most manufacturers have a webpage on how to spot counterfeits of their specific brands based on the actual counterfeit items they've encountered.

I respect your opinion & I agree it may not be viable in homes (but I think electricians should do it nevertheless).

Consider this: If your MCB is protecting a high-end equipment, I think it is a good option to have the inexpensive PAT to be sure than to be sorry later Besides if you are buying from various manufacturers, or from an overseas manufacturer especially (& we know the unwritten law of the land that most aren't even manufactured by the brands themselves but by their vendors/OEMs) a tester like this comes nifty!

Apart from this we (not myself but some other department in our company) use it for demonstrating the MCBs we drop in our systems so as to ensure our brand performs like a Merlin Gerin.

I agree with you that there are other ways to check the counterfeit.

 

[Engineer54]

Most of the electricians on this site are self employed one-man bands, no-way would the expense of an MCB test kit such as you have been issued, be a viable proposition, be they house bashers, commercial or industrial. ...I would even go as far as to say that it would even be outside of most smaller outfit's/companies price range.

 

[Marvo]

I respect your opinion & I agree it may not be viable in homes (but I think electricians should do it nevertheless).

Consider this: If your MCB is protecting a high-end equipment, I think it is a good option to have the inexpensive PAT to be sure than to be sorry later

I'm going to disagree about general electricians testing MCB's. In commercial andespecially domestic installations MCB's are used to protect the cabling of the installation against thermal damage due to overload, they're not protecting the high-end equipment or the appliance itself. They're notoriously poor at protecting against marginal overloads even up to double or triple their rated tripping current and even more sometimes depending on their curve of thermal operation. When it comes to short circuit protection and magnetic operation it's a cascade arrangement where if one MCB downstream in the network fails to operate the upstream MCB will trip to the fault still giving the network being supplied equal protection.

Add to this the lack of financial viability of carrying portable current injection kit plus the safety aspects of this kind of procedure and kit, I'm firmly in the no camp at the moment.

 

[Engineer54]

I'm going to disagree about general electricians testing MCB's. In commercial andespecially domestic installations MCB's are used to protect the cabling of the installation against thermal damage due to overload, they're not protecting the high-end equipment or the appliance itself. They're notoriously poor at protecting against marginal overloads even up to double or triple their rated tripping current and even more sometimes depending on their curve of thermal operation. When it comes to short circuit protection and magnetic operation it's a cascade arrangement where if one MCB downstream in the network fails to operate the upstream MCB will trip to the fault still giving the network being supplied equal protection.

Add to this the lack of financial viability of carrying portable current injection kit plus the safety aspects of this kind of procedure and kit, I'm firmly in the no camp at the moment.

I quite agree with you Marvo, i should have mentioned something along these lines, instead of concentrating on the financial burden side of things. Any high end equipment, ...any equipment come to that, if it needs/requires close thermal/magnetic protection, then the manufacturer will have/should incorporate suitable protection measures.

Exactly the same as the fuses in plug-tops and FCU's are not there to protect appliances and equipment, only the cord/lead supplying them...