Now What? How to start building your off-grid system
By Renee Donaldson
Please note that EcoDirect strongly recommends you hire a licensed electrician or installer (fill out our form here for some help finding one) because installing an off-grid system by yourself can get you electrocuted or destroy your components. If this happens because you tried to install the system yourself, EcoDirect is not responsible. Now that the disclaimer is out of the way, let’s begin!
Start it Up
So you have all of your materials for your system and you’re wondering where to start. Here is a step by step process to help remove some of the fog.
Before you begin, be sure to go through your checklist to make sure you have everything you’ll need. Once you start putting things together, finding out you’re missing pieces will cost you time. One critical piece of equipment you might not think of at first is a quality voltmeter.
First, identify all of your power sources. Lock out all of your breakers and disconnects. Remove the fuses. Make sure that absolutely nothing can conduct electricity. Then build your array.
Once this is complete, keep your home run wire off to the side and wire your AC service panel. Add in your inverter so you have you L1 and neutral wires in, but do not connect to the array just yet. We want to make sure that everything is wired correctly alone before wiring it all together. Double check that all breakers are in the open (off) position.
Now we want to add in the DC breakers. Wire in the breaker that goes between your battery and the inverter first. Always insure that the breaker is in the open position (off) before landing any conductors. Hold off on connecting your batteries for right now. Next, wire your home run cable into your combiner box. Make the series connections with in your combiner box, and go ahead and make the interconnections with your battery bank. Again, keep your battery bank separate for right now, this will be one of the last connections made. In particular the positive conductor should remain removed from the battery bank.
Next, add in your breaker that goes between your battery bank and your controller (Please reference Home Power Issue 137 on Battery to Inverter Circuit Breaker AIC & Sizing). Insure this is your DC positive conductor going to the breaker. Once you have all of your breakers and/or fuses in place and everything looks good, go around and complete a torque check on your system.
Now it's time to make the final power connections. Remember to check voltage and polarity as you move along. Make sure that your home run wire is in you combiner box secured. Check for voltage and polarity. Again the positive conductors are going through the breakers. Check to make sure that the breaker from your array in your combiner box is OFF. Make your final battery connection. Be sure to continue to double check the parts you are using are in fact compatible with one another, double and triple check polarity on the DC conductors.
At any point if you get an incorrect reading or if something doesn't make sense, stop. Work backwards until you are able to find out where a mistake was made (perhaps you made series connections instead of parallel, for example). Once you are certain that your batteries have been properly wired for your inverters nominal DC voltage. Use a meter to check your voltages along the way. At this point, nothing is on, but everything should be connected.
Alright! We are cool on the DC side. There is no AC power yet, but we are going to start turning things on. First close (turn on) the DC breaker from your PV array to your charge controller, then close the DC breaker between the inverter and the battery bank. Be sure to check the voltage on the inverter at this point as well. The final connection will be to close (turn on) the breakers to your AC Service Panel. Once this has been completed, you want to go to all of your load breakers and make sure that everything looks good and makes sense.
Shut it Down
Now that we’ve taken you through the process of turning everything on, we are going to tell you how to shut everything down. There are a few reasons that you may have to shutdown your system:
- Equipment Failure
So in the event that you need to shut down your system, here is a step by step guide to help you complete the task in a safe manner.
First, open (off) the breaker between your PV array to your Charge Controller, then the breaker between your charge controller and your battery. Go to your load center and turn off all of your loads and breakers there. Shut off the inverter to generator/grid power. Turn off Inverter to main AC service breaker.
Lastly, turn off the breaker connecting your battery to the inverter. At this point, everything should be off, but it is imperative to double check that there are no live wires. Remove the positive conductor directly on the battery bank. Use probes to test series connections to make sure that there is absolutely no current flowing. Probe with a volt meter to insure there is no power within the system. Once you are positive that everything is off and that you have no live circuits, proceed carefully.