Code Systems Steve Taylor Photovoltaics, inverters, and batteries have made major improvements just in the last 10 years. At one time, competing with traditional power sources was totally out of the question. Even now it doesn't really PENCIL OUT, but we are indeed on the threshold of a break even point. For many years, solar panels immediately brought to mind a hippy living in a school bus with panels on the roof. I have known many people that started out in a cabin or bus (including myself). Those people were responsible for bringing this industry into the public view, and to prove that it DOES WORK. This is a very high tech industry, and I feel it should be treated as such. Meeting electrical codes is part of renewable energy's growth process. Code Compliance Anyone can go to the book store, purchase the National Electric Code book, and read NEC#690. I recommend that anyone installing their own system do this. But, there is more to it than that. You must open an electrical permit, walk an inspector through the system, and get certified. The problem is that most all other electrical safety requirements apply, whether it is for a solar system, or anything else. So, not only do you have to comply with chapter 690 concerning Alternative Energy systems, you also have to observe standard electrical safety such as: wire type and size, mechanical safety, proper spacing of components of different voltage values, breakers vs. fuses, special signs, and much more. Another problem is that local codes vary from one county to the next. For example, flexible conduit is commonly used here in Washington, but it is not legal in California. Some of the high points the inspector will be looking for is: Fused Array Disconnect (DC Rated) This disconnect provides the capability of disconnecting the array from the charge regulator and batteries. This unit should be DC rated, and have fuses of a slightly higher value than the array peak current. In the event there is a short in the array wiring, then the fuse would blow instead of allowing your batteries to send 900 to 2,000 amps through the charge regulator. The disconnect provides fire safety and the convenience in disconnecting the array. Array Grounding The solar array mounts and frames should be grounded directly with an 8' ground rod. Grounding reduces the possibility of lightning damage should your system take a direct strike. Battery Enclosure & Batteries Battery enclosures vary from one installing dealer to the next, but basic guidelines include: Fully enclosed, and not readily accessible by unqualified or unsuspecting people (such as a 2 year old with a wrench in his hand). This vent should be as vertical as possible, and exit from the highest point of the enclosure. Although it is not required by the code book, the batteries should be well insulated from the floor, so the cold can not conduct directly in. Batteries like to be around 78ˇF. In most cases, our battery enclosures are insulated to a value of R19 or better, on the floor and all four sides. In warm climates, I would still recommend insulating the battery from the floor. The battery negative terminal should be grounded to an 8' ground rod, along with all other neutral lines in the home. Inverters Inverter ac outputs can be hard wired in conduit. Also, the inverter should have fused disconnects on the ac output AND DC input. These fuses should be of slightly higher value than the inverter rated input/output capacities. The inverter ac output fuse and disconnect should be totally independent of the home's main breaker. Inverters should be securely mounted well away from the battery gasses. Signs & Warning Stickers Homes with multiple voltage sources such as 12 volt lighting and 120 AC should have signs at both main breakers and outside at the service entry stating something like: CAUTION MULTIPLE VOLTAGE SOURCES. Other signs and stickers include: ARRAY DISCONNECT, INVERTER DISCONNECT, CAUTION BATTERY CHARGING AREA, DANGER HIGH DC CURRENT AREA, 120 VOLTS, 240 VOLTS, 12 VOLTS, 24 VOLTS, ETC. We have these stickers in stock here at the store, if anyone needs them. There is more to it than the items mentioned, but those are the main ones. You should all consider including them even if you don't want to get inspected. I recommend that all code quality systems should be done by a qualified, established sales, service and installing dealer. Other advantages of a code inspected system include the availability of bank financing, and home owner's insurance. So protect your investment in renewable energy by meeting the electrical codes in your system. Steve Taylor is the owner of Steamco Solar Electric, the only ARCO Solar¨ factory trained dealer in the state of Washington. He specializes in code complying, renewable energy systems. STEAMCO SOLAR ELECTRIC, 2700 Cantu Ln. NW, Bremerton, WA 98312 or call 206-830-4301.