More ground questions

Old 05-25-15, 07:13 PM
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More ground questions

so many people have different ideas of proper grounds ..... Here is another scenario.
If you install a small solar system (not tied to your grid system at all)at your house for power back up and you want to ground the inverter and panels/batteries
on the back roof and the grid service ground is 100 ft put in another ground rod out back.
But some people say that in the event of lightning you can create an imbalance problem between
the 2 ground rods if they are not connected by a wire.Voltage can build up between them due to potential difference and damage equipment. Even if the 2 systems are totally different and not connected at all.
Is it really that bad to do this,install another rod, if you install a lightning arrest unit as part of the solar system??
Old 05-25-15, 07:58 PM
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Yes, in the event of a near by lightning strike you can have a voltage difference between the two grounding electrodes. Yes, installations without a bond are done all the time, sometimes with no harm and other times with disastrous results.

In case of a direct strike you should hope to have a goose in between the two systems because it will be cooked.
Old 05-26-15, 02:30 PM
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A solar power system or generator system with all separate wiring and receptacles and with no proximity of conductors or components let alone transfer switch or other interconnection with any other wiring involving ground rods would not need its ground rod to be bonded to such other ground rods.

Code requires that if you have more than one ground rod being used for anything or something or other including antennas connected to radios powered by the home electrical system then all rods most be interconnected using #6 copper wire or equivalent.

Exception: Any such grounding electrode conductors that would have to cross lawns, sidewalks, etc. to get to rods for different buildings may be summarily omitted.

The grounding electrode conductors described here give an easier path for voltage differentials across horizontal distance on the ground that are likely to exist momentarily in the vicinity of lightning strikes to dissipate without using and burning up coax shields or equipment grounding conductors or (by jumping through insulation) using juxtaposed current carrying conductors of wiring inside the house.

Last edited by AllanJ; 05-26-15 at 02:59 PM.

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