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That just confirms what I said. The point I was making is 300 ma is more than enough to kill you. 30 ma is quite painful but not considered lethal to a healthy person and about what a Stun Gun supplies. Enough to knock you down and paralyze you for a few minutes. Now if you are on your roof and get hit with 30 ma may kill you when you fall off the roof. Grounded systems are dangerous.
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MSEE, PE -
Normal Array Leakage Current
I went out to get a handle on this; here are the results.
The system is in 2 identical arrays that had been running all day.
Array description: 5 strings of panels: 2 strings with 10 panels of 72 cells and 3 strings
of 12 panels of 60 cells; 6" X 6" cells. About 820' of PV 10 gauge wire, 75' of that
underground in plastic conduit. 460' of 6 gauge buried in plastic conduit.
Mostly sunny, 1 deg F. Both sides measured the same. Operation was at about 404 VDC.
I went out while power was dropping, about 1KW, and opened the DC disconnect switches.
All power connections were broken. Either array open circuit voltage was about 454 VDC.
Voltage drop across a 1 ohm resistor was monitored by a DVM, to determine the current.
One end of the resistor was tied to ground metal, and a probe on the other end made
contact with an array + or - terminal. If there was leakage current from the array to
ground, it could flow through this resistor. Each milliamp of current would produce a
millivolt across the resistor. I noted there was a small spark on INITIAL contact, probably
due to static charge of the capacity to ground (No, I didn't measure the capacity THIS TIME).
Current through the 1 ohm resistor was too low to register on my MV DVM. I switched
to a 1000 ohm resistor, 1 mv = 1 micro amp. I found the current would start around 5
micro amp, but over some seconds trail off to 3 micro amp or less. This was consistent,
on either the + or - terminal, either array.
I concluded each array was properly insulated, and the current was lower than I anticipated
given the voltage and amount of insulation involved. If it were a steamy rain soaked day
I would expect an increase, but that measurement will have to wait till summer. Bruce RoeComment
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Hi wondering if someone can help,
We had pigeons nesting under the solar panels, so had a company come in and put chicken wire in the gap, however this didn't work and they managed to still get in. We researched and saw that you can put metal mesh from the aluminium frames down to the roof and this works. My husband did this with metal screws and washers. He did this sat on the roof and when he got to the back where he couldn't sit on the roof any longer, he went to finish it off standing on the ladder.
As soon as he touched the solar panel he got a shock, so the panels were live.
In all the forums he looked in, it said you can drill into the aluminium frame, he drilled into the lower part.
What do we do now, to stop the panels being live?
Please help, thanks in advanceComment
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