Thanks, yes, I have tested all breakers. That's how I found this one. I did the full range of tests, including ramp tests etc and recorded all values, before the electrician who will issue the certs comes and does his own. I installed a full RCBO board in my new kitchen (which is the main test job) and this board was previously installed in another space to serve other circuits. It was the only faulty MCB.
For the record, I looked into trading standards in Kent. They hive reports straight off to Citizens Advice. They in turn made it clear that they are not the slightest bit interested in this, and nor would trading standards be either, unless I could identify a criminal individual or organisation.
Hager has no complaints facility on line. Surprising. When I rang customer services, it took some time to explain the problem as the operator in customer services had no idea what an MCB was. It was suggested that I contact the seller. When I suggested in turn that it may be counterfeit or faulty goods, they suggested I return the item to them if I wanted to, at my cost. So that is a no then!
An MTN140 Type B 6kA costs £3.99 with free prime delivery (same or next day) from Amazon. Only £2.46 at Edwardes. It is simply not worth messing around with. In this case I do not believe that the item was counterfeit. It is just faulty, and if they can make them that cheaply (retail must be double ex factory cost) then it is inevitable that some will be defective.
Interesting experience though.
