Solar is LIVE!

by Ben N on June 6, 2017

IMG_5033Bam! My solar is now fully operational!

This morning, the electrical inspector stopped by. I pulled off the cover of the MidNite Solar AC Disconnect Box for him to look inside. That was about it. VERY simple inspection for the solar. I also had a sample of the Enphase trunk cabling to show him. After that, he took a look at the rest of the general garage wiring. So, I now have Final Electrical Inspection for both the solar AND the whole garage!

Not too much later, I got a phone call from the power utility. Last week, I sent an e-mail saying that I would be doing the wiring this past Friday, and installing the panels on Monday (which was yesterday.) After the installation yesterday, I sent another e-mail saying the installation was complete. This morning, Greg, the utility representative asked if they could come over to perform the Anti-Islanding Test. YES, PLEASE!

Anti-islanding is an important feature of grid-interactive solar inverters. The inverters create 240V AC electricity in sync with the grid. If I consume LESS power than is created from the solar panels, the excess power flows out over the grid to my neighbors. In the event of a blackout, we would NOT want current to flow back to the grid! An unexpected second source of power would run backwards through transformers to even higher voltage. An electrician, working to FIX the blackout could come in contact with LIVE conductors that he would have expected to be dead because he disconnected the other end! High-voltage power has the potential to be lethal, so the Anti-Islanding is an important test. The upside is that it’s also a safety feature built right in to any modern inverter designed for grid-tie solar.

The point is, it’s important, and the utility wants to test the automatic shut-down feature of the inverters before giving me permission to connect to their grid.

Twenty minutes later, Greg, an electrical engineer, and other utility employee hopped out of a van in my driveway.

IMG_5035Their first question was “Where is your big inverter?”. I had to explain that there WAS not single central inverter for the solar. They were used to seeing a big box on the wall with a display that always tells the power output in real time. I explained with my micro-inverter system just uses a simple connection to one breaker. There is no central box with display. I also have a smart-phone and web interface for the micro-inverters, although those wouldn’t be appropriate for the split-second measurements for the anti-islanding testing.

I suggested they simply throw an ammeter on the one of the hot wires. We turned on the power – both the 30A breaker and the outside AC Disconnect. The inverters will NOT produce power for a full five minutes after connection to the grid.

In the mean time, the engineer unscrewed the cover for the pulling body on the inside of the garage, pulled out a hot wire, and clamped the ammeter to it. I explained a little more about how my system worked, and showed some sample components to the utility employees as well.

Once the five minutes was up, we could see power starting to flow on the ammeter display. Greg had out his stop watch while the engineer flipped off the main breaker to simulate a blackout. Instantly, power stopped from the micro-inverters. The testing was quick and simple, but required to make sure that the system will always be safe for line workers.

IMG_5038After that, the guys pointed out to me how my reprogrammed utility meter will now show both energy consumed AND energy produced. My digital meter has an underscore symbol at the bottom of the display. This takes the place of the black mark on the disc of the old mechanical meters. When it animates to the right, I’m using power, when it animates to the left, I’m producing power. In another part of the display, there is an arrow. When it’s a left arrow, I’m producing, when it’s a right arrow, I’m consuming. I also showed the utility folks a sample piece of my roofing and the S-5 clamps.

So, that’s that! My roof is now producing power!

I set up my software metering so, please visit the link: https://enlighten.enphaseenergy.com/pv/public_systems/PqBp1213167/overview (Please ignore the extra two solar panels shown in the display. Those were two that I experimented with earlier and am trying to figure out how to delete!)

In some ways, it’s completely anti-climactic. There were no sparks or noise when flipping the switch. There’s no whir of a wind-turbine or the putt-putt-putt and fumes of a gasoline generator. The solar panels just sit there, quietly producing energy. Very modest, those solar panels, working so hard, yet looking like they are sitting there not doing a thing!

Until next time, stay charged up!

-Ben

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Wiring for Solar

by Ben N on June 2, 2017

We got the wiring for the solar done!

My electrician, Ross, came over and we set to work on the wiring. I already had mounted electrical boxes to the racking on the roof and connected the Enphase Engage cable to the boxes with liquid-tight cable strain reliefs. I also made the conduit connections from the boxes down to the edge of the roof. However, I still needed to run conduit from the edge of the roof down to where the disconnect would be. Since I didn’t know EXACTLY where the box would be, I hadn’t done that section of conduit.

IMG_4920My brother had made a block which matched the garage trim on which I could install the disconnect box. This would provide a solid raised surface to install the box and a place for the siding (still to be installed) to run in to. I centered the box on the wood blocking and marked where the knock-out on the back would go. I then drilled that 1 inch hole with a Forstner Bit. On the SIDE of The MidNite Solar disconnect box there is a  1/2″ knockout for the incoming wire, but we are using 3/4″ conduit. So, Ross pulled out his step bit, and we drilled out the box for a 3/4″ connection for the wiring from the roof.

We screwed the blocking and box to the side of the building, using a short level, to ensure both were plumb (mostly to look nice.) We then ran the conduit down so that a 90 degree elbow would be directly horizontal from the hole in the side of the box. The hole in the disconnect is actually out from the wall just a bit, so we needed an offset. I already experimented with heating PVC conduit to shape it, but hadn’t done a particularly good job. Ross showed me how to measure the offset. We then cut a piece of conduit the right length and stacked up scrap wood to the same height as our offset. We then heated the PCV and put one end on the pavement, the other end on top of the scrap wood, and then just pushed and held the ends down. This made a very nice custom offset. That piece then went into the side of the box with a gasket.

We ran a short piece of conduit through the wall and installed a pulling body on the backside. It turned out that we ended up needing a short conduit extension on BOTH sides of the elbow to reach the main electric panel! I was so concerned with the box on the outside (being at the right height, meeting code in various ways, etc.) that I missed simplifying the installation on the inside of the wall by just lining it up with stock conduit components! Oh well.

IMG_4923At this point, all the conduit was complete, and we could start the actual wiring pull. This project is two 20 amp 240V circuits. That’s a hot, hot, and neutral for each of the two, plus a ground wire, 7 wires total. Ross set up several rolls of wire on an extra wide reel. The plan was to feed the wiring in a straight line from the bottom box up to the middle box, and then pull just the top circuit to the top box. One of the hot wires used purple insulation (instead of the typical red) so that we had the “Purple wire group” and the “Red wire group”. This made it a little easier to keep the two circuits straight.

The top box was pretty straight forward. I simply used wire nuts to connect the four wires from the Enphase cable to the four wires I pulled through the conduit to the box. I put a small dab of No-Ox in each nut before making the connection.

Next, at the middle box, I needed to splice the ground, and connect the Enphase cable to the wires of the second circuit. This circuit would be the middle and bottom rows of solar panels.

At the bottom box, I pulled out a loop of the second circuit wiring, cut it and then spliced it together with the bottom row Enphase cable. The “Purple wire group” was only connected to the top row of panels, and simply passed through the middle and bottom junction boxes.

IMG_4929Ross cut the wires on the ground to a length long enough to wind their way through the conduit down to the disconnect box. I pulled up the wires, taped the ends together, and then pushed them down through the conduit to the disconnect box. Ross made the electrical connection at the box and already ran and connected the 10 gauge wiring from the disconnect box to the main breaker panel.

After that, the electrician packed up and left. (Good! They get paid by the hour! My plan with building the junction boxes and installing them and the conduit on the roof was to minimize how long I’d have an electrician there. Gotta stay on budget!)

I checked over everything on the roof and closed up the weatherproof junction boxes.

At the MidNite Solar AC Disconnect, I installed the inside cover and the slider that connects the two circuit breakers to the big red lever on the face of the box exterior. One of the few things that my Utility specifies is the exact wording on the box. I mail-ordered a red plastic sign earlier in the week, and it happened to show up that morning! I peeled off wax paper from the sticky-back tape and applied the sign to the box. I had also ordered a placard from my utility meter. My Utility didn’t specify that I need it, but many utility companies do. It didn’t cost much more to have a second sign in the same order, so I purchased that second sign and put it on my meter.

IMG_4935Other than just a little clean-up, the wiring was now complete. Frankly, I COULD have done it all by myself. I already used a wiring calculator, and double-checked which size conduit to use, etc. I really wanted an electrician there because I was required to have an electrical permit, which specified a particular master electricians license. I also wanted a little advice just to make sure everything was to code, and lastly, what I really wanted was just the confidence that I was doing everything right. (Which I was, but I didn’t know that for sure.) It was also nice to have somebody there for advice and if I ran into any problems.

It was also good to have an electrician because he has all the spare odd electrical bits in his truck (instead of yet ANOTHER run to the store) and he had the large reels of wire (which are very expensive to buy from the big box home improvement store.)

Still, I was the guy designing the system, and the guy up on the roof pulling the cable and making connections, so I WAS getting real experience building a solar system.

Later in the day, Wayne stopped over, and we got some of the siding started.

The roofer is supposed to come this Monday with his lift. This project really requires some power equipment to get the solar panels onto the roof. The guy that I hired to roof the garage has a nice lift along with a trailer to deliver it and the experience to operate it. Between the two of us and one person on the ground, we SHOULD be able to make pretty quick work of installing the solar panels.

Until next time, stay charged up!

-Ben

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Electric Boxes on Roof continues

by Ben N on May 29, 2017

I did some more work today on the junction boxes on the roof.

For one thing, I couldn’t get one of the 1/2 liquid-tight connectors to seal up. I ended up replacing it with a 3/4″ version instead. Of course, by that time, I had sort of messed up the whole box and ended up re-doing it.

I also started connecting the three boxes with conduit, which is pretty straight-forward. Lastly, I was trying to figure out the best way to get the conduit AROUND the roof and down the side of the building. I experimented with a few PVC elbows and got the conduit roughly where I want it to go. However, it still doesn’t look great. I think I can solve that by using a 90 degree pulling elbow. That should make a nice tight connection around the roof. At this point, I haven’t cemented any of the PVC. I’ll wait until the electrician comes out so that I can ensure things are to code before making anything permanent!

I’ll also want his input on the BEST way to make the conduit look nice! I have an appointment with the electrician later this week, but we’ll have to see how the weather holds out. I can’t walk the metal roof in the middle of a thunderstorm!

Until next time, stay charged up!

-Ben

PS: In the photos below, please note that NO plastic touches the roof. The PVC boxes are screwed right to the aluminum racking, and the conduit runs UNDER the racking, but does not touch the roof. At this point, I’m basically experimenting with cheap materials to see what will and won’t work out well on the roof. The PVC boxes will all be UNDER the solar panels and not visible when the project is complete.

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Electric Boxes for Solar Roof

by Ben N on May 28, 2017

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I had to double-check and saw that it’s been over TWO WEEKS since my last solar garage update. I’ve just been busy, working out of town and on the weekends.

In the time that I’ve had, I’ve chipped away at getting the racking installed over the course of several evenings. After that, I also installed the micro-inverters and trunk cable.

Today, I got to take a look at what I plan to do for the electrical junction boxes on the roof. I have three sections of 240V trunk cable – one for each row of eight solar panels. Each of those cables needs to go into a junction box where it can connect to plain 12 ga wires and get routed through conduit down to the side of the building. From there, it will go into an AC Disconnect and then finally into the building to the main circuit breaker panel.

I purchased several outdoor rated plastic electric boxes. One was a plain double-gang box. The other two were 6″x6″x4″. The nice thing about the double-gang box is that it already has threaded holes on it for conduit adapters to thread right in. However, it’s a relatively small box, but big enough to connect my Enphase trunk cable to some standard 12 ga wire and send it down the conduit.

At the other two boxes, I need a little more space. There will be more total wires coming through and two of the three rows will be connected in parallel. Connecting them all together would be too much current for the 12 gauge wiring, whereas having each on its own would require another circuit. Those boxes are also deeper. That will allow space for connecting the conduit and having it run UNDER the racking.

IMG_4807The larger boxes are plain, there’s no holes in them. I drilled two 1 inch holes so that I could insert a threaded 3/4″ conduit connection. I also drilled a 3/4″ hole so that I could add a 1/2″ watertight connector for the trunk cable to enter. I also made sure to use silicon sealant at all the ports and the drilled holes to make sure they stay weather-proof.

Each of the three boxes just gets mounted to the Iron Ridge racking with self-tapping screws. This past Thursday, I attended some solar training sponsored by Iron Ridge and Enphase. I asked the Enphase representative about the “proper” way to attach junction boxes to the racking for their system and mentioned that I had trouble finding the right brackets. His response was that they used to make those but stopped because “Everyone just screwed the boxes right to the racking anyways…”

So, while just using a few screws to connect the boxes feels like a very low-tech solution and perhaps not the “correct” way, it turns out that’s how everyone was  doing it anyhow!

I also cut two pieces of 3/4″ plastic conduit to run from the top box to the middle one and from the middle to the bottom box. I’m still trying to figure out the best way to wrap the conduit around the edge of the roof and have it visually look okay. I might just buy some spare PVC conduit parts to have handy so that when I do get the electrician over, we can come up with a solution together while minimizing the time (and thus cost) of having the electrician there.

I also need some blocking to which I can attach my AC Disconnect. We don’t have the siding up yet , and we will want a nice flat surface for the disconnect. My brother (who is the one with all the construction experience, and acting as my general contractor for the garage) said that he would make up some blocking for me for the disconnect. Then we can put up the siding around it when we get to that point.

IMG_4809I haven’t cemented the PVC conduit yet. First, I just want to make sure that everything lays out right. I also ran into a problem with the 1/2″ waterproof connectors I was using for the trunk cable. The connectors are rated for cable thickness up to exactly the thickness of the cable that I’m using. When I was at the store, I even tested one on a sample piece of my cable. It worked fine in the store and again at home later. Of course, once I was on the roof, it was nearly impossible to thread on the connector. It was as though the cable was just a little too thick, and I couldn’t get the threads started. Even when I did, the plastic connectors would cross-thread and distort. I was able to get two of the three connectors to tighten down, although I wasn’t real confident with them. I might have to head back to the store and see whether or not the 3/4″ version of the same connector will work or not.

As it is right now, I’m expecting the electrician to come out at the end of the week. (Unfortunately, the weather report suggests thunderstorms that day!)

I’ve also been trying to nail down my roofer on a date. He did a fantastic job on the metal roof and has a man-lift which would be perfect to get the solar panels up. With my experience so far, I really don’t feel that there’s any good safe way to install the panels on the roof WITHOUT some sort of power equipment. The roofer would be able to provide both the equipment and the experience to operate it. He would also transport it to and from my property. Add that all up, and it makes more sense to hire a guy and his gear for a day then try to go rent something and transport it myself.

I talked to him last week. He’s been very busy too, but has promised me a day to work on my project. I’m hoping to hear back from him after the Memorial Day Weekend.

At this point, the solar project feels like it’s in a holding pattern. I’m also trying to think of the best way to make sure the solar panels go on STRAIGHT and LEVEL when I put them up. In my experience with things like shingling, we usually used measurements and chalk lines. With the solar panels up on the racking, there’s no easy way to compare them to a chalk line. (No idea how well that would work on a metal roof anyways!) Perhaps I’ll just stick a large square behind the panels and make sure it’s at a right-angle to the racking. I’m pretty confident on the overall racking installation. One other reason why I’d like to hire the roofer is not just for his man-lift, but also for the experience he has making things square and level.

The MREA Energy Fair is coming up real soon and my goal has always been to have the solar up and running by then. Besides the installation, I still need the electrical inspection AND have the Power Utility to do a test before I can commission the system. Who knows how long THOSE take to happen!

I hope that THIS becomes the week that I REALLY get something done on my solar, but it is heavily dependent on other people’s schedules…

-Ben

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Fall Protection

by Ben N on May 10, 2017

IMG_4476

Probably my single biggest goal of building my own solar system is simply to NOT FALL OFF MY ROOF!

Once I got the first piece of solar racking up, I had a brace which let me get ON the roof. At that point, I realized that the metal roofing is INSANELY slippery and would NOT be walkable. Not only did I need some sort of roof jack, I also needed fall protection.

IMG_4430This past weekend, I took a three-day hands-on workshop-style Wind Turbine Class. I already knew the instructor, which is how I found out about the class. Fall protection and safety is a BIG DEAL in the wind industry, so I made sure to ask about fall protection (and how to best deal with it on my project.) In the end, I got a personal loan of an automatic retractor strap.

This device works much like a safety belt in a car – gently pull it and it moves – jerk it, and it locks in place.

The next thing I would have to figure out is how to attach the strap to the roof. Fall protection anchor points are commonly used for roofing, but are installed BEFORE the roof goes on, screwed right to the structure of the roof. I have a brand-spanking-new metal roof, which I don’t want to put any holes in. I do have two “extra” S-5! brand metal roofing clamps. The problem with using those is that they are really a permanent clamp. Once they are on, they are difficult to remove, and installation leaves a mark on the roof. (The set screw actually BENDS the roofing, which is what makes the clamp so powerful.)

IMG_4489So, one solution would be to install a clamp for fall protection, and leave it there permanently. The downside of that is having an ugly clamp there for all eternity. That actually got my mind going. What if there was some OTHER use for the clamp later? I was trying to figure out a way of using MULTIPLE clamps to span the ridge vent. In a web image search, I realized that what I wanted to do is actually similar to a weather vane mount! Perhaps I could install a few clamps, and then use them for a decorative weather vane later on!

I still didn’t know the best way to attach my fall protection to an S-5! clamp. I would need some sort of heavy welded ring or something similar to which I could hook the safety. I started looking around for what I had for materials and realized I had a piece of angle iron longer than 16″. I could drill two holes through the angle, attach an S-5! clamp to either end, and clamp the whole thing to the roof. This would give me a solid 16″ grab bar I could hook anything I want to.

IMG_4474I got out my drill and bit set and used the 1/8, 1/4, and 3/8″ bits to drill the two holes to size. Starting with the small bits and working my way up, it was SURPRISINGLY easy to drill the holes….. which was good, because I ended up doing it twice.

I fit the clamps to my drilled angle iron and tested the bolts. It all looked good.

Next, I needed to climb up onto the roof. My solar racking (being used as foot-holds) only extends half way up the roof. I pulled up a step-ladder and laid it flat on the roof, with the ladder’s feet braced against the top piece of racking. I crawled up to the peak, where I could stay in place by uncomfortably straddling the ridge. I installed both clamps rather close to the ridge, centered on the south face of the roof. This should keep the fall protection up above the top of my finished row of installed solar panels. When I went to bolt the bar to the clamps, I realized that the roofing is NOT actually spaced to exactly 16″ – it’s a hair less than that. I would have to climb back down, re-drill my holes, and come back up. Because the measurement was less than one hole diameter, I’d have to move over on the angle iron and drill a new pair of holes, instead of just one.

So, one more time, I drilled the holes and climbed back to the roof. This time, I was able to thread the bolts through the iron and torque them down into the clamps. The iron felt very solid on the roof.

IMG_4484Next, I connected the auto-retractor strap and hooked it the the climbing harness, which with some forethought, I was already wearing. I crab-walked down the roof to see how far I could get. Uh-oh. I couldn’t reach the bottom without running out of strap. On the device, part of the model number was “12″. I was afraid that it probably referred to twelve feet of reach with the strap, and I was right. My roof is about 18 feet from the peak to the eaves. I went and got my engine hoist lifting strap, looped that around my angle iron anchor, and then attached the fall protection device to it. This time, I was able to walk all the way down the roof to the ladder.

IMG_4483At that point, I can unhook the harness and then loop the auto-retractor to either the ladder or the lowest solar rack. Then I just need to make sure to walk down the ladder safely.

After once again checking everything over it seemed very solid and secure. The only thing I will likely do is add a piece of foam or some sort of padding under the retractor strap reel. If I move to the far edges of the roof, the reel slides around and can drag on the roof. It’s brand-new, and I’d like to keep it from getting scratched up!

I now feel MUCH more confident about safety on the roof.
No, I didn’t get any more of the racking installed, but I’m now ready to tackle the rest of it (as soon as I get some more time!) and can then begin installing the cabling and micr0-inverters.

Until next time, stay charged up!

-Ben

PS: As I was finishing up, I did a few short controlled slides on my butt, lowering myself down the roof. Suddenly, I remembered the fact that when I was a kid, my Dad built us a homemade slide in the back yard. It was wood, covered with sheet metal used for roofing. I think the angle was even about what my roof is. The metal was dark brown and really soaked up the heat of the summer sun. We would go out to use the slide and get burned if we were wearing shorts. My typical hand-me-down corduroy pants slipped right down the slide, while preventing burns.

PPS: If I’m working on the upper part of the roof, I’ll reconnect the retractor directly to my anchor point. That way, there’s no slack due to the purple strap. Also, I did look up the real-world testing on the S-5 Clamps. For that style, and the type of roofing I’m using, each one will hold over 1,000 pounds, or 2,000 lbs for the two of them. In theory, I could suspend a Geo Metro from my roof.

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