Solar PV "Power failure"? Technicians in North East? Help!

QrizB

Telegraph_Sam said:

Will do. I get the impression that the system needs to "settle down" from time to time. As before the MDB (I said RCD by mistake) won't allow me to re-set it.

If they're working correctly:

- The MCB will trip if the current in the cable exceeds the rating of the MCB. Your MCB is rated at 16 Amps. Your inverter shouldn't be able to exceed that (and it hasn't tripped the MCB in the previous 13 years) so it's likely there's a fault with the inverter, the cabling or the MCB.

- The RCD will trip if the current in the live conductor is different to the current in the neutral conductor. This implies a leakage of current to earth somewhere, due to a fault on the cable, the inverter, the MCB or the RCD.

Any or all of these things could be faulty and need replacing.

Qyburn

Acronyms are all over the place here with MCD and RCB and probably others, none of which actually exist, being bandied about. In the real world you probably have ...

MCB .. which will trip on overload or a high current short circuit fault.
RCD .. which will trip on even a very small mismatch between L and N, effectively on fault current to earth. Typically 30mA fault current will trip it.

Which is tripping?

Telegraph_Sam

To be discussed with the electrician. Noteworthy is that the RCD has been relatively stable throughtout. And that the MCB has seemed to "recover" overnight, enough to provide current for several hours the following day.
I have purchased replacement RCD and MCB's so the obvious route would to get the electrician to replace both in addition to whatever checks he deems relevant.

Telegraph_Sam

Our messages are getting a bit out of sync ..
It is definitely the MCB that is tripping. With the RCD it is less clear cut. Does one have an effect on the other?

QrizB

Telegraph_Sam said:

Our messages are getting a bit out of sync ..
It is definitely the MCB that is tripping. With the RCD it is less clear cut. Does one have an effect on the other?

They shouldn't, no.

You did report a few pages back that, while your main problem was the MCB, the RCD was occasionally tripping too. Was that correct or were you mixing up your terminology?

Telegraph_Sam

Our messages are getting a bit out of sync ..
It is definitely the MCB that is tripping. With the RCD it is less clear cut. Does one have an effect on the other?

QrizB

Telegraph_Sam said:

Our messages are getting a bit out of sync ..
It is definitely the MCB that is tripping. With the RCD it is less clear cut. Does one have an effect on the other?

That's the same message you posted an hour ago. Are you having problems with the forum software?

Telegraph_Sam

Much worse! Domestic drama. Fuse here blown > no internet, no phone connection > and I suspect that the electronics got mixed up (I had not been expecting to continue our conversation ..).
Allowing for different time warps is the situation here reasonably clear? MCB is under suspicion, RCD - the jury's out.  MSE software seems to be in the clear. Return of electrician awaited ..

Telegraph_Sam

Latest: As I was struggling to get the MCB to re-set this morning  a msg came up in the Aurora screen "Inverter OK". Now they tell us

Telegraph_Sam

I suppose that there must be some gut-feel logic in the switches being less liable to trip in cool weather than in hot.

Electricians are obviously a dying breed.