Lightning Protection
This basic scheme shows the use of Delta Lightning Arrestors in various
locations.
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Grounding Panels |
From the wiring page... A ground wire needs to be installed:
1. along each panel to the PSPV, preferably using a Grounding Lug similar to the one
pictured at the right. I generally use 8 or 10ga, please check the code (you
may need to use 6ga for its resistance to damage).
2. from the PSPV to a ground rod driven into the ground near the Solar
Array. I generally use minimum 6 ga wire (or same size as 3.), please check the
code for details.
3. from the PSPV to the PS2DC ground bus connection. I use the same gauge as
the positive/negative conductors. This PSPV Photo shows the
ground wires mentioned above. Plus it shows a Delta LA302-DC Lightning
Arrestor. Learn More about Delta Lightning Arrestors. |
Click Image to Enlarge |
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Ground Rod Installation |
This photo shows 2 each 8 foot copper clad steel rods in
the ground. Two ground clamps connect the 6 ga solid copper wire to the
Ground Bus of the Outback PSPV. |
Click Image to Enlarge |
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Grounding Notes |
A protection system with a poor ground is the same as having no
protection at all. Too many times proper grounding has been overlooked.
Recommended grounds are the utility company ground, a ground rod, well
casings, and cold water pipes that are of continuous metal. A note of
caution, sometimes the metal-cold water pipes are repaired and/or extended
PVC piping. The introduction of PVC material renders the cold water pipe
ground unacceptable. A thorough investigation of a cold water pipe ground is
important since the PVC repairs or extensions may be covered by drywall.
Grounds that are unacceptable include sprinkler pipes, PVC pipe, conduit,
buried wire and any ground that cannot be verified.
Bonding ensures the most effective ground. Bonding ties all of the grounds
in the building together electrically. If there is a rise in ground
potential and all of the grounds are bonded, no damage will occur since it
is differential voltage that causes problems.
It is absolutely necessary to make sure that the ground used for the AC
power is the same as the ground used for the data-line surge protectors. A
common ground reference must be achieved for all equipment. All ground wires
must be as short as possible and it is imperative that the ground wire not
be coiled nor looped. The ground wire must be as straight as possible,
remember that it must be the path of least resistance. Regarding the
diameter of the ground wire, the larger the better. The larger the diameter,
the better electrical conductivity. Finally, the earth ground resistance on
which the whole grounding system relies, must be less than 5 ohms.
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Grounding Practices |
See this link for interesting articles on PV and
Grounding...
http://www.iaei.org/subscriber/magazine/series.htm#pv |
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