You can make your own antennas from Peach cans. Cantenna they call them. Good for 1.21 Jigawatts (sic).
Yes, there's no requirement to have a "competent person" connect the DC. I'll connect the cablles to the DC isolator in the house first and then connect the panels last at dusk with a heavy black stage curtain over them for saety.
I’ve never considered that panels could be dangerous. I’ve never had anything to do with them. The only DC I’ve ever dealt with is the normal 12v everyday stuff. In fact I didn’t even realise that panels can produce voltages high enough to be dangerous. In my uneducated mind I’ve always thought of them as sort of trickle chargers.
When I had mine fitted on the house The cable’s run down in a conduit to the garage to where the inverter is, The electrician told me never mess about with them he said you probably wouldn’t be able to let go of them if you did.
My string of panels creates between 500-600 VDC and is capable of putting out about 10A in direct sunlight. That's nasty if you somehow get between the two terminals. I always wait till dark if I need to do anything with them or the inverter. Interestingly, even at night you can see a significant voltage, especially if the moon is full. Probably not enough to shock, but definitely enough to cause a spark.
I always thought the received wisdom was that anything over 20 odds volts may be dangerous under certain conditions, I believe this is why Fluke meters show the lightning symbol when a voltage is read over a certain threshold.
The problem is that there is no scientific threshold. Someone may be able to withstand around 100VAC, or 150V when its DC. The next person it may be 80VAC and 130VDC before it's felt and/or painful or damaging. A lot depends on skin resistance and other factors. Once I was repairing a telephone line while it was live, which was fine (I thought) because there was only 12VDC or so on it - until someone decided to call that extension at the moment I had my fingers on the bare wires. That causes about 100V AC to get put on the circuit which is what old analogue phones use to ring the bell. It was a slightly unpleasant feeling but a valuable lesson.
Perhaps Fluke are being conservative, but as @Coda said it depends upon skin resistance, humidity, so many factors.
Nominal phone line voltage is about 50V across the A and B lines. But, as you say, the ringing voltage is higher. If you want to stick your tongue on a phone line, make sure noone's about to call you
how are you wiring up the panels? Ours are set in rows on the roof, connected in series across the row then the rows are connected in parallel. That way if you lose / break a connection or panel you will only have lost that one row rather than the whole lot.
Apparently people have been killed by 36 volts AC in the USA working in wet conditions. The other factor that DC causes is that corrosion of damp connectors is asymmetric .. the more positive wiring may vanish .. plus the heating effect of the current through a corroded connector can melt it or cause fire. I just couldnt get anybody at work to be worried about the dangers of an installation of two sets of five 20V panels in series. Yes worry about 240V like its going to leap out and bite them, but seawater soaked solar power cable connectors carrying 100VDC, no problem..
I think @Fruitcake said he's having a separate DB installed. Thats a way around having to connect into the existing DB then having to upgrade everything associated with it.
It was my poor attempt at humour due to the reset! I was too late to tell @Merlin Cat to look in her glove box
I sold my van yesterday afternoon, by the evening I apparently hadn't. It was like a Bobby Ewing shower moment.
Apologies if you have this twice, but my post disappeared yesterday! Great thread @Fruitcake and would like to try a similar (OK the same ) system, but wondered where you sourced the panels etc? Looks like the panel company have a UK outlet called Segen?
