2015 11

Updated: 2015-11-10

I am going to separate the computer and network power systems from the main house system. I had everything except the panels and I got a great deal on those. Now I have the following components for the dedicated computer/network power system:

1. (3) 225w Sunpower E18 panels
2. Xantrex C40 charge controller with control panel.
3. (8) 95ah batteries in rack
4. 3KW modified sine wave inverter

I am still debating how how I will mount the three panels either on a portable skid-mount or on some really high pole mount arrangement that can be adjusted seasonally. I had thought about mounting them on the roof but that isn't in keeping with my aim to be portable with nothing permanently mounted anywhere.

These panels are a lot smaller than my Sharp 230w panels.

Updated: 2015-11-12

I have the unistrut but am waiting on the slick nut caddy hardware to mount the panels.

I prefer to use the slick caddy hardware ("CADDY SLICK strut nut, 1/4-20") to attach panels as I can slide them around with the nut inserted into the channel easier.


These are the best things I have used for mounting panels if you don't mind drilling into your panel frame.


I ordered 5-sets of male/female MC4 connectors with crimp-on hardware and will build my own wiring harness into the combiner box. first I will create (3) pigtail sets of MC4 connectors to raw 10ga wire that will be attached to the (3) fuse holders and onto the buss bar.

If I use another portable skid mount design it will have to be about 100' away from my office. I would have to buy some 6-ga cable for such a long run. That will be very expensive as well. The cable is usually well shielded and a tough exterior so I leave it above ground so it can be rolled up and re-used when I set up the portable panels elsewhere.

I am investigating a pole mount attached to the house itself lifting it 8-10' feet above the roofline but into the sun from morning until sunset as the west side of the house has sun almost until the end of daylight. I like the idea of a 4" pole mount being anchored right to the house and then lifted above as the price of a 30' pipe is much more than a 12' pipe. In order to mount something heavy the pipe will have to be anchored to something very very strong. This might be easier if I simply purchase a 30' pipe and then mount it in concrete base

I already have the combiner box but also had to order a waterproof fitting so I can run all the cabling into the box. I also need to locate some 1" metal strapping so I can fabricate the mount for the combiner to the back of the 3-panel array you see below.

It looks like I will shorten the unistrut to match these Sunpower E18 panels. There is not quite enough room to fit a fourth panel unfortunately. They are much smaller than my Sharp panels, I did not factor the size-change into my design and am reworking the entire plan to see if I might use a different approach in mounting these small 225w panels.

I am going to have to drill (4) new holes on the length side of each (2-per side) panels there is not a lot of clearance between the inner wall and the edge of the frame back so the holes will have to be perfectly positioned for drilling as almost no tolerance for 'slop'.

Updated: 2015-11-13

I have the panels mounted and secured to the unistrut. I will probably disassemble everything now after I label and identify the parts. It is simply too heavy to work with while partially assembled. I have still not decided on if if it will be a pole mount or another portable skid-mount. If you zoom in to the unistrut where the panels are connected you will see the slick caddy nuts.


They are simply the best for this kind of thing even though you have to bolt them from, behind using 1" 1/4-20 bolts which means a lot of small wrench action.


I still have not decided if I want to cut off the excess unistrut or wait to see if they are of some use in the new mounting method. Best to wait as I can always slice them off at any point.

The Great Redesign

I am installing a new Xantrex 3012 True Sine Wave Inverter/Charger now which needs to have the AC input and outputs completely isolated. I need to install a main lug box in the house next to the main circuit breaker panel to feed AC in to the new inverter/charger. I am going to use a 30A breaker in the lug box since that is my input on the inverter as well.

Updated: 2015-11-21

I have finished rebuilding the main power system and rewiring everything to work with Xantrex isolated input/output design. I have to say it went very well and was simple and straightforward. Their concept is that the inverter/charger handles transfer, power monitoring (switching to inverter/line) automatically or manually depending on how you have the inverter/charger configured. I was forced to change everything because the Xantrex 3012 Inverter/Charger requires isolating the input and output AC. It sounds complicated but in fact in order to use the inverter you must rely on the 3012 to do everything (transfer, sensing) via the SCP (System Control Panel.) It seems to me I should be looking at getting a spare control panel (scp) and eventually a spare inverter/charger.


This was how it looked on Saturday. I had already begun using the inverter but was unable to charge it via the grid if I needed as there was s fault condition coming up because I had the neutrals connected in common, which worked with the old inverter but because this one requires isolation I had to disconnect the AC input neutral at the inverter to avoid the fault condition. The AC input wasn't being used any way unless I was charging. I was getting all the power I needed on the panels except for the days it snowed which was enough to have me manually connecting the neutral, using the transfer switch and then charging the battery pack.


I finally had the time to remove ALL of my previous design and rewire everything the way Xantrex requires. First I removed all the wiring from the transfer switch and dismounted it.


I pulled the wire bundle back through the conduit and can re-utilize them they are about 20-feet long.


I utilized the 10ga wiring (orange) for AC inverter input and output, the connectors on the inverter/charger handled the larger gauge perfectly. I crimped on some connectors for the ground bus I never really trust those but had no other way of doing it. Although I do have L2 coming from the pole I don't really need it right now. I did wire it into the main lug breaker that I just installed but did not run L2 into the inverter or the panel. I can always run another wire if I have to but I don't have any red building wire right now either.


The AC input and output feeding into the inverter. If you look near the conduit coming up from beneath the cabin you will see a second hole where I drilled right into the floor joist. I have to repair that area and reinforce the joist where I cut into it. I made a huge mistake and eye-balled it instead of actually measuring.


This main lug box sits between the grid and the AC input of the inverter/charger:

In this case, the "grid" is a buried wire going to an outdoor pole with a meter and load center which has a 60A breaker I chose for the house. The outdoor load center feeds the water pump, an RV space there I currently park a shipping container and the house. The local power company has a meter installed there a that pole (and one up at the observatory.)

I installed a 30A breaker in the main lug box and wired L1 and L2 through the breaker but only L1 is wired into the inverter. The way things are now in order to switch to battery power (inverter) I just turn of this main breaker and I am running from batteries. It is that simple. In my case the grid is the power company of course. I use it like I would use a generator. It costs less to run than a generator though


You will see another view of the mistake I made when drilling the hole for the conduit. I will be patching that soon. The inverter/charger sits underneath the bed and is well ventilated. It is much quieter than the Tripplite MRV2012UL was.


The Xantrex SCP sitting on top of the main lug breaker box I just installed.

I have to build a thin instrumentation panel underneath the load center to accommodate all these control panels.

I no longer have a sheet metal press so I will have to have something fabricated from sheet steel so I can primer it for a nice white enamel coat or three.

I am going to install a breaker between the charge controller and the battery pack as I keep having to power cycle the charge controller. It seems to be going into an overcurrent situaiton which sometimes causes it to shut down on me. I need a safe way to detach and power off the charge controller from the battery bank. I ordered one of these today.


The overcurrent situation I mentioned above is merely because I am producing too much power occasionally for the Xantrex C60 but it doesn't always seem to handle the situation gracefully. Powering it off and on always clears it up though.

Updated: 2015-11-26

This 675W array is for a second power system I am building just for my computer and network equipment. It will be charging the set of UPS batteries in the 19" telco rack above.
The plan is to run all my computer and network equipment full time on inverter and establish a separate and redundant power system so that no matter what I can work and maintain network connection to the outside world.

I built 3-sets of MC4 pigtail cables that will run from the panels to the array combiner box. I crimped the connectors and hopefully did a quality job. I made each pigtail 92" and plan on trimming any excess once they are wired into the combiner box.


Updated: 2015-11-28

This combiner is for the second power system I am building just for my computer and network equipment. The array of (3) panels above and this combiner will be attached to the same portable skid mount systems used above 100' away from my office on the north-east side of the house. I will be picking it up soon from the person that builds them for me.


When I do this I always start with a pilot hole (of course.)


We use a hole saw to do the rest.


I installed the waterproof connector on the combiner box and then also fed the cables in but will leave them as yet untrimmed at their 92" length for now. I will coil up the excess and place it back into the combiner box and seal it for now.


I didn't tighten anything snug yet as I will be trimming the cables further. Since I used MC4 connections I can now just unplug the box and wait for the rest of the project to catch up.


I ordered 100' of VNT6-3C-G cable from my favourite vendor. 6-3C THHN-PVC Tray Cable with Ground


This is very good stuff I have been using this for my main power system for the house it is durable and versatile. This is of course 6AWG (3-conductos plus one ground.) I will be able to re-use this for a long time if I ever take my solar power systems 'portable' I will simply wind and unwind them onto a cable spool.

Applications: In free air, raceways or direct burial. In wet or dry locations. Approved for direct burial, Class I, Div. 2 industrial hazardous locations per NEC. Permitted for Exposed Run (ER) use in accordance with NEC.

Size: 6 AWG
Number of Conductors: 3
Conductor Strand: 7/.0612
Ground Wire Size: 8 AWG
Minimum AVG Insulation Thickness: 0.91 mm / 0.036 inches
Minimum AVG Jacket Thickness: 1.52 mm / 0.060 inches
Outside Diameter: 17.53 mm / 0.690 inches
Copper Weight: 0.300 lbs per ft
Net Weight: 0.434 lbs per ft
Allowable Ampacity: 75 Amps