40 amp MCB live when off? Faulty?

[AJB Temple]

Fair point. I'll think it over how to proceed.

 

[brianmoooore]

Might be interesting to compare the weight with a known genuine one.

 

[DPG]

No way could I resist opening that up and having a look.

And definitely report it. If it's a bad batch then action needs taking rather than leaving them in place ready to cause an incident when they don't trip on a fault.

 

[pc1966]

If you do decide to open it up yourself, take plenty of in-focus photos before and during the dismantling process!

 

[AJB Temple]

I weighed it versus a genuine Hager from TLC. Using my bakers scales which weigh digitally to the gram. They are identical. Shaking and it tapping it does not rectify the fault. I can't get it apart non-destructively, so I will be returning it for a refund and have already left a negative review (which may well get blocked).

This is actually the secon Hager MCB we have had fail. We had a defective one in a different CU in a kitchen about 2 years ago, and in that case it just tripped constantly when there was no circuit fault. That one was identified by an electrician who didn't bother with any tests (and said he was not certified anyway - he was near retirement) he just swapped the wiring over and put tape over the dud. I keep meaning to whip it out actually.

 

[Risteard]

Have you verified that there isn't an erroneous connection to another circuit?

 

[littlespark]

Have you verified that there isn't an erroneous connection to another circuit?

He has said earlier that there is no circuit connected to this mcb at all… it is a spare way, but he found power on the outgoing side when the breaker was off.


OP; It would be sensible to check all the breakers for the same thing now you’ve found one faulty device.

 

[Risteard]

He has said earlier that there is no circuit connected to this mcb at all… it is a spare way, but he found power on the outgoing side when the breaker was off.


OP; It would be sensible to check all the breakers for the same thing now you’ve found one faulty device.

Apologies. I read it that there was a cable connected to it, but that it was no longer used.

 

[AJB Temple]

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.