Install A Proper Ground System

Standard practice on any electrical system is to drive a copper-plated steel rod (usually 8 ft. long) into the earth. This is a minimum procedure in an area where the earth is moist and hence more easily conducts electricity. The north side of a building, where the rain falls on the ground from the roof is a good place. Where ground is dry, especially sandy, or where the array is relatively large and high up, more rods should be installed, at least 10 feet apart. Connect all ground rods together via #6 bare copper wire, buried. Use only the proper clamps (not solder) to connect wire to rods. If your array is some distance from the house, drive ground rod(s) near it, and bury bare wire in the trench with the power lines.

Metal water pipes that are buried in the ground are also good grounds. Purchase connectors made for the purpose, and connect ONLY to cold water pipes, NEVER to hot water or gas pipes. Beware of plastic couplings -- bypass them with copper wire. Iron well casings are super ground rods, but you may need to drill and tap a hole to get a good bolted connection. If you connect to more than one grounded object (the more the better) it is essential to electrically "bond" them all together using min. #8 copper wire. Connections made in or near the ground are subject to corrosion, so use proper bronze or copper connectors. Your ground system is only as good as its weakest electrical connection.

If your site is rocky and you cannot drive ground rods deeply, bury (as much as - feasible) at least 150 feet of bare copper wire. Several pieces radiating outward is best. Try to bury them in areas that tend to be moist. If you are in a lightning-prone area, bury several hundred feet if you can. You can save money by purchasing used copper wire from a scrap metal dealer. If it's insulated strip off the insulation. Use copper "split bolts" to clamp odd pieces together. The idea is to make as much metallic contact with the earth as you can, over the broadest area feasible, preferably moist. If you need to run any power wiring over any distance of 30 feet or more, and are in a high lightning, dry or rocky area, run the wires in metal conduit and ground the conduit. Any time you cut a trench in the earth, consider expanding your grounding system by throwing in some bare copper wire.

What To Connect To Your Ground

GROUND THE METALLIC FRAMEWORK of your PV array. (If your framework is wood, metallically bond the module frames together then ground them.) Be sure to bolt your wires solidly to the metal so it will not come loose, and inspect it periodically. Also ground antenna masts and wind generator towers.

GROUND THE NEGATIVE TERMINAL OF YOUR BATTERY BANK, but FIRST make the following test for leakage to

System Grounding ground. Obtain a common "multi-tester". Set it on the highest "milliamp" scale. Place the negative probe on battery neg. and the positive probe on your ground system. No reading? Good. Now switch it down to the lowest milli or microamp scale and try again. If you get only a few microamps, or zero, THEN GROUND YOUR BATTERY NEGATIVE. If you DID read leakage to ground, check your system for something on the positive side that may be contacting earth somehow. (If you read just a few microamps, it is probably just your meter detecting radio signals.) Connect your NEGATIVE POWER to ground ONLY AT THE BATTERY BANK. Do NOT ground the negative line at the array or at any other points.

GROUND YOUR AC GENERATOR AND/OR INVERTER FRAME and AC neutral wires, conduits, and boxes IN THE MANNER CONVENTIONAL FOR ALL AC SYSTEMS. This protects from shock hazard as well as lightning damage. Follow directions for your generator or inverter or consult an electrician.

ARRAY WIRING (and other outdoor wiring) should be done with minimum lengths of wire, tucked into the metal framework then through metal conduit. Positive and negative wires should be run close together wherever possible. Bury long outdoor wire runs instead of running them overhead. Place them in grounded metal conduit if you feel you need maximum protection.

SURGE PROTECTION DEVICES bypass the high voltages induced by lightning. They are recommended for additional protection in lightning-prone areas where good grounding is not feasible (such as on dry mountain tops) especially if long lines are being run to an array, pump, antenna, or between buildings. To be reliable these devices must be capable of conducting thousands of amps (for a short time!) and must have an indicator to show internal damage. They must be special for low voltage systems, so contact your PV dealer.

SAFETY FIRST!!!! If you are clumsy with wiring, or uncertain how to wire properly HIRE AN ELECTRICIAN!

Windy Dankoff is Owner/Operator of Flowlight Solar Power, POB 548, Santa Cruz, NM 87567 or call 505-753-9699.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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