Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1206
| Posted: 05:07am 22 Jul 2024 |
If I am aware of an approaching electrical storm or if travelling away for a few weeks I still turn off power points for most appliances especially big screen TVs etc to avoid a disaster. You raise an interesting point though, we have 13.5kW on the roof and I never considered disconnecting the PV input or mains to the inverter. We do have some hefty surge arrestors in the switchboard and I do get some comfort in knowing that there are taller structures (yes some are power poles
) and even taller trees around us.I think if I was in a more remote location and relied maybe 100% on my off grid solar power your suggestion to temporarily isolate the panels from the MPPTs/GTIs for impending storms is a good idea.
When I was in my early teens we had 2 decommissioned 32V Dunlite towers and I wanted a good antenna for shortwave so I fitted a porcelain insulator each end and ran a wire between them with a feed down to my workshop. One warm no clouds light breeze balmy afternoon I entered the workshop to investigate a weird buzzing sound, there were blue sparks in a few places on the wooden bench top and when traced out it came from the disconnected antenna feed and was discharging via odd bits and pieces to a ground point I could easily throw multiple continuous sparks 5-10mm long to ground.
Needless to say when I realised the implications of lightning activity I quickly removed and dismantled the antenna which had seemed like a good idea at the time. The point of the story is that if steps have not been taken to ground the roof or and at least the rails for the Panels, you dont need a lightning strike, just atmospheric ionisation could cause a static build up and flashover. This is really only relevant to a handy man home install, if its setup on a wooden frame for instance, maybe grounding the panel frames might not have been considered.
Re the heatsink I would be looking for something around the same size as the power PCB, the old Aerosharp 1.5kW is fine. Given the quantities of the GTIs they made, it always intrigued me why they chose horizontal fins for their heatsinks, when vertical fins would actually achieve better needed airflow, they certainly had the resources to specify something that would have worked much better for the same price but never did.
Edited 2024-07-22 15:09 by wiseguy