Independent powered homes use standard 120 volt AC wiring just like any city home. But with independent power, you will need a few extra wires. Some will bring solar, wind, or hydro generated power from outside to the battery area. Extra equipment in the house, like a battery meter and generator start/stop switch will need wiring. And to save power, you will have more than the usual number of wall switches to control many local task lights. Extra wall switches also control AC outlets so any appliances that steal your power even when they are turned off can be cut off dead by the switch. Perhaps you will need a few low voltage outlets for some energy saving DC appliances like phone message machine, fans, special refrigerator, or pump.

While planning your unique home, don't forget outlets outside. Summer is when solar electric homes have lots of extra free power, so you may want an electric lawn mower and weed eater or fountain pump. You might want light and power in a shed or detached garage, for power tools, or an emergency battery charger to start the car. Special 12 volt DC motion sensor lights at each entrance, the woodshed, or the outhouse will light up for you even if the inverter (your AC power source) is in idle mode. Even an outhouse should have its chandelier! Plan ahead and wire for all these needs while you build.

CHECKLIST FOR HOUSE WIRING

• AC BREAKER BOX: The inverter in your power system produces 120 volt AC. Normally no 240 volt AC will be used in the house, only 120 volt AC. So you just feed the same 120 volt hot wire to both legs of the AC breaker box. Since most inverters are limited to 20 to 60 amps maximum output, you don’t need a 200 amp main breaker. Eliminate the expensive main breakers by "back feeding" the entire box through two of the load breakers, one for each "leg" of the breaker box. This passes electrical code.

• BACK-UP GENERATOR AC WIRING: Power from the generator should go into the power equipment room on a separate wire, (never fed back through the same wire that carries inverter power out to the generator location). Mark this wire generator direct. This will supply power directly from the generator to the AC IN terminals of standby inverter, and to any special generator direct outlets you might want to add in the power room for other battery chargers. Standby option feature on most inverters (or a separate transfer relay catalog #O-TS30 if the inverter lacks this feature) will automatically switch generator power through to house circuits when the generator runs. When the generator is shut down, household circuits automatically switch back to inverter power. Never connect the generator output directly to the house circuit breaker box if inverter power is connected there. 
  

• You may also want to run a generator direct wire to its own outlet in the garage, or shop. Here you plug in battery chargers which should run only from generator power, as well as a welder, air compressor, or other items the inverter is not large enough to run. Also run a generator direct line for any 220 volt power you might use directly from the generator, like a very deep well pump. No need for separate generator and inverter wiring elsewhere in your home, because generator power automatically comes through all the regular wiring when the generator runs.

LIGHTING IS MORE EFFECTIVE WITH LESS POWER if you have lots of local area "task" lights. Use 15 watt fluorescent lights under cabinets to be close to the kitchen counter and in workshops. Put each wall or ceiling light on it's own wall switch so you can select lighting precisely where it is needed. More, smaller lights use less power with more lighting options than a large central light.

• Timer light switches are great for lights often turned on and then forgotten, as in children's rooms, closets, stair wells, and particularly outdoor lights. The tap of a button or a wind up timer starts the light and sets the time anywhere from a few seconds to an hour, then the light goes out. The timers help keep the peace if lights are often forgotten and carelessly left burning. 

• Motion sensing lights outdoors are great for arrival and departure. Most AC time and motion sensing switches work with inverters, but only if the inverter is running, not in search mode. We offer DC light timers and motion sensors that are on duty all night with almost no power used.
  

• Light dimmers should not be used unless you have a sine wave inverter. And to date, most compact and other fluorescent bulbs cannot be dimmed.

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SPECIAL PURPOSE 12 or 24 VOLT DC CIRCUITS
Plan a few DC circuits in the house for items that have great energy saving advantage using DC power direct from your battery.  One DC circuit to each room is usually enough for "low power, long hour" applications: recharging flashlights and cordless tools, doorbell, intercom, phone answer machine, cordless phone, 2 way radio, desk calculator, or portable stereo. Some energy saving refrigerators, especially small ones, are DC powered, also water pumps, and ceiling fans may also need a DC circuit. DC hot water circulating pumps are used for floor heat systems, water-bed heating, or compost toilet heating. You may want DC circuits to front door or outdoor motion sensing lights so they can operate whether the AC power inverter is active or not.

DC OUTLETS are not standardized. Beware the old RV cigarette lighter plug. They are poor quality, illegal in houses, and will burn. For quality and durable 12 or 24 volt outlets, just use standard 240 volt 20 amp AC outlets. These usually pass code inspection used as DC outlets if there are no actual 240 volt outlets in the same house. They fit the same outlet boxes and same cover plates as regular 120 volt AC outlets, and just as easily attach to wire with a screwdriver. These are listed in our catalog as #O-DC OUTLET and #O-DC PLUG.

To figure the correct wire size to use for 12 and 24 volt DC circuits, use the wire size chart printed with the solar module wiring in our catalog. Generally, use 12 gauge wire up to 35 feet or 10 gauge for runs up to 50 or 60 feet. (Stranded wire and solid wire of the same gauge carry the same ampere rating).

OTHER WIRES TO ADD

• TELEPHONE WIRES should be kept far from your AC power wires. Inverters that are not True SineWave can cause a buzz in the background on your phone if the wires are run beside each other for any length. Use shielded and twisted pair telephone wire with the shield connected to ground to minimize this common noise problem.
  
• SOLAR MODULE WIRES   You will need appropriately sized COPPER wires to bring power from solar modules to the battery / utility area. Our solar mount and wiring catalog page has charts showing the wire gauge to use for various distances for 12, 24, or 48 volt battery. 

• POWER MONITOR WIRING  You may want a battery monitor meter somewhere in the home other than the battery room. While wiring the house, install some 4 or 6 conductor twisted pair intercom or phone type wire for the remote meters like TriMetric.
  
• START AND STOP CONTROL FOR GENERATOR will be needed   in the house if you get a remote control generator. 4 conductor wire 12 gauge does it.
  
• AND ALL OTHER usual extras are more difficult to add after the house is built than when the walls are still open: TV antenna cables, extra telephone wires and outlets, speaker wires for stereo, doorbell and intercom or other special wiring.
  

SOME APPLIANCES STEAL POWER -- EVEN WHEN TURNED OFF

PHANTOM LOADS : Some appliances need to be disconnected from power completely just like pulling the plug, when not in use. Remote control TV, VCR, stereo, and microwave oven, office equipment (computers, fax, etc.) and garage door openers may use a little power 24 hours a day even when switched off! These are called "phantom loads", and taken together, will keep an inverter turned on and waste a large part of your power, if not discovered.

• The cure is to have many of your AC outlets controlled by a wall switch to shut off power completely. This is preferable to pulling the plug every time. In existing houses, just use the outlet strips, (an extension cord with an outlet strip and built in switch) to easily disconnect power robbing items.  One strip can switch your whole stereo/TV assortment, or all your computer items together.
  

To learn the rest of the story that the above was selected from, read the BACKWOODS SOLAR ELECTRIC SYSTEMS solar electric catalog/guidebook, and the other instructional books listed in the catalog. 

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