Generally, MC 4 connectors from  reputable makes (Stäubli come to mind, there are many other makes) have an environmental rating of IP67 but only when the correct cable diameter is used and the glands are done up as per the instructions. This means they are then fine for short periods of immersion. However,  generally cables and connectors left in the sun and the wind and the rain, will not last as long as the same part under some sort of shelter, even if it is just tucked under the panel, and I'd certainly expect things to be neatly tied up and not flapping about in the open or able to be trodden on or tripped over.

Apart from mis- assembly , as alluded above, the other problem  is if they have been mated while damp, as then that sealing works against you and the ingredients for corrosion are sealed in, instead of out.

What sort of problems are you seeing - it is quite possible that the connectors are not the real problem, but rather like seeing mismatched screw heads on door handles can be a flag to check the rest of the woodwork, a sloppy approach to what you can see, may indicate the same (lack of) attention to detail in other areas less obvious.

Mike.

Hi Mike, 

Thanks for your reply. I have attached photos. 
Basically, inverter is picking up loads of issues. 

I am starting to wonder if the installations were in fact correct or not? The cables are submerged in water. 

Is this correct installation in the first place as per BS7671? 

Appreciate your expert review and feedback. 

Thanks,

Kiran

Proper PV cables are pretty robust - Elland for example say their PV cables are suitable for AD8 - immersion - and I'd guess other reputable brands will be very similar - so the cables themselves should be OK on that score.

The panels do look to be at a very shallow angle though - and with likely shadowing from that concrete(?) upstand shown in the last picture, I wouldn't be at all surprised if the performance was pretty disappointing during the winter months when the sun is low in the sky.

   - Andy.

Its not as bad as it might be !
That roof top weed pond reminds me why truly flat roofs are not supposed to exist according to building control. ;-)  If there are joints sitting under that day after day, I'd be looking to lift them up out of it, though if the cable is unbroken it should be fine - cables underground are often in ducts that are full of water for a large chunk of the year, but you can't see it.
The use of concrete blocks suggests the metal frames are sat on the roof and retained only by gravity and friction - which from a roof integrity perspective is the best,  but means that the low angle is probably more about keeping out of the wind than a tropical location with near overhead sunshine.

Are the flat strips cable guard that is not really attached to the cables ?

I'm assuming the panels are wired in long series strings and the inverter electronics is elsewhere - what are the reported issues?

Mike.

mapj1 said:

If there are joints sitting under that day after day, I'd be looking to lift them up out of it, though if the cable is unbroken it should be fine

Unless I'm much mistaken, looking at that last photo, several of the connectors have been laid on top of buckets!  I'm not sure which section of BS7671 that corresponds to 

not sure which section of BS7671 that corresponds to

133.5 ?

  - Andy.

not sure which section of BS7671 that corresponds to

133.5 ?

  - Andy.