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Installing a grid intertied
solar electric power system

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Overview System
Financing Panel
Hardware Grounding Rail

June 25
.  The building is nearly 20 years old and the cheap shingles are overdue for replacement.  My roofer used "Landmark" architectural shingles made by Certainteed.  I selected a lighter shade to reduce the heat gain from the summer sun.  Scott Paraskevakos and his son did a great job, if you live in mid coast Maine and need a roofer call him at:837-2760
June 26
Load panel installed - showing netwrok cableI installed the load panel on the ground floor of my workshop at the closest corner to where the 240V wires will drop down from the solar panels on south west corner of the roof.  I ran 8/3 Romex cable back to the main breaker where it ties in to a 30 Amp double breaker.  In the load panel I installed 2 15-Amp double breakers and pulled 12/3 wire up to the 2nd floor in preparation for pulling it through to the roof to weatherproof junction boxes.

I also installed an outlet on its own 15A breaker below the panel for the Enphase EMU unit that I will mount next to the panel.  Then I ran a CAT-5 network cable from my web router in my office upstairs down to near the panel.
August 1
junction boxAfter I got the rails mounted, I climbed back up and installed the electrical junction boxes.  I drilled holes through the roof and fed the Romex out and through the bottom center of each box via a Romex connector.  Then I bedded the box down in silicone and screwed it down, then beaded the edge with silicone too.  I mounted it diagonally to reduce the risk of ice dams causing stress that could lead to leaks.  I used a 6X6 box so that I would have plenty of room for the 4 wire splice.
August 14
Disconnect breaker box and Enphase EMUYesterday I picked up 12 inverters (waiting for 9 more) and the EMU.  I installed the EMU next to the disconnect breaker box and powered it up and connected it to the web.  After a while the display indicated that it had connected to the web, so it is all ready for the inverters and panels!

Click here to learn about the inverter installation.  I had to wait over 2 months to get these new inverters, and only got 12 of the 21 I needed, and had to find a second source to get the remaining 9.  They are very new and in very high demand.

August 28
We finally got a day of nice weather - not raining, too hot or too humid.  So I decided it was time to put up panels on the 12 inverters that I have installed, the remaining 9 inverters will arrive next week.  I called my friends Topher and Barbara, and neighbor Charlie and his son Taylor, and also drafted our niece Gaia who was visiting before starting her first semester of college in Boston.  We got them up in about 2.5 hours and had fun! 

Thanks to Gaia and Barbara who stopped to take pictures during the process!
Before each panel went up we taped a sheet of cardboard to it so that it would be covered when we plugged it into the inverter.  We made sure that 2 pairs of hands were holding the panel at all times for safety.  We started with the lower right panel, and then added 2 above that, and moved left from there.  We took a lot of trouble to get that first panel square to the rails and as they went up we had to constantly tweak them to get them to line up.  It helped to have the lower panels secured first so they would support the ones above.  Taylor and Gaia with covered solar panelTopher and Barbara hefting a panel to the roofCrew installing solar panels

L: Taylor and Gaia with a covered panel
mid: Topher and Barbara lift a panel up to Charlie and I
R: Charlie and I placing a panel as Topher and Gaia stand by
Here we are plugging the solar panel into the inverter underneath it.  It's important to keep the panel covered when connecting it since the connections will have live power if the panel is exposed to the sun.  You don't want to mess with over 150 Watts of DC power!
Plugging panel into M190 inverterPluggin in a solar panel

L: Charlie holds the panel while I plug it in.
R: Installing the 7th panel.
MC3 connectorsMC4 connectorsThe solar panels I bought came with MC3 style connectors (shown at left), so I had to order microinverters with the right type of mating connectors.  These connectors are a soft rubber press-fit that can be separated relatively easily.  The MC4 style connectors (shown at right) are a locking type that require a special plastic tool to separate.  Different panels come with one or the other as standard and it's important to match connectors between the panel and inverter.
Barbara preparing a parts kit for the next panelThroughout the project Barbara managed all the hardware, and prepared a set of parts for each panel as it went up.  We only dropped one or 2 parts, and this system ensured that there would not be too many parts lost if we dropped a whole container full.  The WEEB washers are $2.00 each and the stainless bolts, washers and nuts are quite expensive too.
Guy torquing down the panel mounting hardware as Charlie watchesPanels secured with mounting clip and hardwareThen we secured the panels with the stainless steel bolts and hardware.  WEEB washers under the panels connect them to the grounded rails and need to be torqued down at 15 foot pounds.  The screws that protrude from each end of the panels (at top and bottom) make it difficult to set one panel directly above the other so I made a wood jig to keep the separation at 1/4".  It is a piece of 1/4" masonite with strips of wood on both sides to hold it up on the panels.   We had some trouble maintaining a consistent vertical gap, and had to go back and adjust the panels a few times.

Charlie (top) and I were the "roof monkeys" on the job.
Some more shots of the installation:First solar panel goes up
Installing the 7th solar panel
Installing the 12th solar panel
After they were all up, Topher walked over the electric meter to watch as I flipped on the circuit breaker in the disconnect box.  "It slowed down a lot!" he exclaimed.  I set the Enphase Energy Management Unit (EMU) to scan for the inverters, and a few hours later it logged them all and showed that it had recorded a total of 3.1kW for the day.  (See the REAL-TIME STATS page for more info).  A nice start for only a few hours of afternoon sun, I'm happy already.  The panels shut down around 7:30pm as they dropped below 5 Watt total output from a max of over 1560 Watts.

September 4, 2009
Yesterday the final 9 inverters arrived and I installed them.  Today my neighbor Charlie and friends Topher and Barbara helped me to install the final 9 solar panels.  It was a blistering, clear, windless day in the 90's ad we were sweating a lot.
Thanks to Rebekah Younger for the photos below
Installing solar panels gatting covered panel into position on the roofSecuring solar panel
At last we're done!    A happy crew celebrated a job well doneI went inside and turned on both circuit breakers. 
Guy turning the solar power on

I set the Envoy to scan for new modules and after a rest break for ice cream and fresh picked blueberries we came back and logged into the Envoy EMU from the LAN.  We saw that all the inverters had been identified and that the system was generating over 2300 Watts!  I emailed Enphase tech support to ask them to update the panel layout on my Enlighten account.