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

QrizB

Telegraph_Sam said:

This shows the MCB's next to the inverter

The one on the left is an RCD. The one on the right is a MCB. Which one keeps tripping, left or right?

The wiring diagram in-between the CU and inverter should show how everything is connected together.

To be brutally honest if you can't tell an RCD apart from a MCB, you probably shouldn't be thinking of opening anything up.

Telegraph_Sam

Easy, it's the right hand one = MCB that has been tripping. My thoughts entirely about getting in an electrician. But my local standby declined. I don't know if replacing the MCB is a particularly complex task

QrizB

Telegraph_Sam said:

Easy, it's the right hand one = MCB that has been tripping. My thoughts entirely about getting in an electrician. But my local standby declined. I don't know if replacing the MCB is a particularly complex task

If the fault is confined to the MCB, it shouldn't take an electrician more than 30 minutes. What might take longer is confirming that it's the MCB at fault rather than anything else.

Telegraph_Sam

Is this the wiring diagram? If all is not clear then it's back to the beginning as far as investigations and causes are concerned

QrizB

I think we're back to "you need an electrician or a MCS-accredited installer, and it's your choice as to which".

Telegraph_Sam

Yea. I'm trying the first route, failing which the second. Is there an online (searchable) MCS database?

debitcardmayhem

Sam again 
https://mcscertified.com/find-an-installer/

Magnitio

As mentioned before,  https://www.susenergy.co.uk/ have good reviews. I know someone who has used them and they were very professional and helpful.

Heedtheadvice

Been watching  the thread and you are getting a good advice. 

If the system does not trip immediately but repeatedly after a period of time when you have lots of  generation  or just randomly the first port of call should be no. 1 on the list above.

As the Main RCB isolator is not tripping then you do not gave an earth leakage fault. 

The Right MCB (MD116B) does a similar job to a fuse and trips if too much current is passing through it. The inverter should be limiting the current to a nominal 16 amps( the rating of the MCB ) . 

At times of high generation power ( probably only in clear sunshine or very light cloud) is when that 16amp current generation is approached, so if the inverter is working properly the mcb should never trip as it needs more than 16 amps and some time to trip. 

It would trip straight away if there was  a permanent short circuit in the inverter or the wiring ( very high current ).

However that is not how you describe the problem and you also say you have not noticed a pattern.

In my opinion it is most likely that the mcb is faulty ( as previously mentioned in the thread) but an inverter fault cannot be ruled out.

MCBs are common , easily obtained everywhere,  cheap, quick to change and therefore not an expensive job. So despite your earlier comment of "forget the ****ing around..." it is the sensible first action   and can be done by any qualified electrician and therefore low cost and easier for you compared with souci g an onverter test/repair (inverter investigation/diagnosis/replacement will be a lot more costly into the several £100s). Wiring and switches can be checked at the same time just in case of an intermittent fault but that is most unlkely if there has not been any damage to them.

( note 1 that to follow regulations you are not allowed to do that mcb work yourself )

( note 2 isolating the inverter at the AC switch will not prove that that the MCB is working properly! )

QrizB

Telegraph_Sam said:
I see that the source is susenergy. I came across them whilst pursuing one of my other avenues. I think their approach is to charge £120  for call out to locations covering quite a large geog area. 

At this time of year your panels will be earning £10+ a day when they're working. Prevaricating for too long is going to end up costing you more than susenergy's call out fee!