2015 02


I haven't had a lot of time to work on anything but today I cut (4) pieces of steel for the combiner mount and drilled the mounting holes.

I don't have a drill press but it wasn't so bad using a hand drill.


I did this rather late in the day so the paint won't be dry until tomorrow. The temperature is dropping rapidly here and overnight lows will be in the low 30s. I will paint the other side tomorrow.


I ended up using a set of commercial (2) combiner boxes. I felt my home made combiner boxes were all right but I liked having something that looked professional and would stand up to the elements better.

I also liked the heavy duty hardware which will allow me to use 8-ga wiring into the house from the combiner mounted on the skid mounts.


I am using (3) 10A fuses on each panel and will use (3) weatherproof fittings to secure the wiring going into the combiner box. I will have to drill holes for those.



I was able to get the mounting brackets painted, drilled a third hole in each bracket and finally mounted securely on the skid-mounts.


I hope to get the weatherproof fittings attached to the combiner boxes (more drilling) and get the wiring attached later this week.



I had a few minutes today to work on one of the combiner boxes. I've drilled out the holes for the weatherproof fittings and cleaned up the cables a bit.



I had some time to make a little progress on preparing the cabin for the transfer switch.

This is what the internals look like on the transfer switch. Not much to it but in a very convenient package. I only have a 60A feed to the cabin so this is more than sufficient. I will switch between internal power and commercial power (electric company) for now.

Below you will see I have mounted it and it's ready for wiring. I have also run the conduit from the inverter through the floor so will wire up the inverter to the transfer switch next. I still have not had a chance to wire the solar panels to the charge controller yet.


The large metal conduit goes up the load center (not shown.)

I ran the 10AWG wiring from the panels to the location of the charge controller inside the house through conduit but did not have time (nightfall) to connect everything. I have to solder terminal lugs on the charge controller side and then run the wiring into the combiner boxes at the panels.

The runs are fairly short about 20-feet so 10AWG will be fine. I used the special very heavy-duty PVC direct burial solar wiring.

I ran (4) wires for 6-panels. Each string of 3-panels is connected to (1) combiner with (2) wires output.

At maximum output each pair of wires will carry about 28A and the wire is rated at 40A so I'm well within limits.

I cannot wait for daylight so I can finally start charging the battery bank from the sun. Up till now it's just been from power supply/charger units plugged into commercial power.

I have the inverter AC output wiring almost finished and will have to install another conduit for the ground wiring and the inverter AC input wiring (to charge the battery bank from commercial power when I have the transfer switch set to commercial power input.)


The above design will allow the battery bank to be charged from commercial power when the transfer switch is in that position. Updated: This design only works with inverters that are not isolating the AC input or output. This design has only been confirmed to work with the Tripplite Invetter/Charger which was a modified-sine-wave inverter.

The Midnite Solar design has the Inverter/Charger's AC IN feed before the circuit breaker which won't work for my design since I am not using a generator. I must instead put the Inverter/Charger AC IN after the circuit breaker so that it is only live when running the power system off commercial power.

I will need to either wire up a second transfer switch or an outdoor socket with a new breaker at the load center to actually connect the generator.

I'll get to that at some point.

I miscalculated the amount of wiring that would need to be run and the conduit I installed today is already full from the panels and inverter AC output.


I don't mind drilling into the floor for the second conduit as I can use the extra conduit for some network and video cable going outside.


I finished wiring up the panels today into the charge controller. I had to solder the lugs on which went well. There was not much sun today, the weather is turning bad and snow is expected over the next few days so I was disappointed in how much power the panels produced.

If you noticed the colored tape on the wires coming in from the combiner boxes outside, that was so I can identify which set of panels. When I was running the wire yesterday I used three different colors to mark what pairs and polarity. One set of 3 panels was "brown" the other "blue" and the positive cables have red tape and the negative cables just have the color of which set of panels.

Next I have to install another conduit, connect the inverter/charger and then get the inverter/charger AC IN and AC OUT cables connected to the transfer switch.



My new C60 charge controller was bad (DOA.)

When the sun first started producing real energy this morning I was very happy and ran to the charge controller to see what was going on. I heard something hissing inside the charge controller and there was the smell of something burning.

The remote display indicated it was producing 16.7V output and the current readings on the remote were not accurate. I checked the voltage at the battery to verify and it was definitely 16.7V.

I quickly disconnected the controller from the combiner boxes and the battery as I was afraid of damaging the batteries.

I measured the open collector voltage from the (3) panels and that was 37.5 VDC.

While troubleshooting I later reconnected just one set of panels and started making measurements.

When I connected the single set of 3-panels and then measured with an ammeter they were pushing 29.7A (the sun was very bright then!) yet the remote display was still only indicating 9A.

I used a Fluke clamp-on meter to measure the current and a Beckman DVM for voltage measurements.

After calling the place I bought it from where they essentially told me I was on my own and to call Schneider.

I worked with Schneider Electric technical support and after a few calls and emails they agreed it was broken. They are shipping me a new controller.

On the second call to the place I bought it (between calls from Schneider) from they tried to tell me my entire configuration was wrong.

They said all sorts of erroneous stuff like the "C60 can't step down from those 36.7V panels and you have to have 12-14V panels" and all sorts of other nonsense.

First charge controllers don't "Step Down" they simply produce a regulated voltage (in my case either 12V or 24V) based on any input voltage within the controller's specifications. They are simply a DC-DC converter in this case.

They tried to tell me that because I had a 12V system it was going to produce too much current for the charge controller because at 12V the current would be much higher than if I had been using 24V system and even quoted Ohm's Law at me.

I kept trying to explain to them that Ohm's Law didn't apply since the charge controller was designed to handle the same amount of current no matter what the OUTPUT voltage was configured for.

Of course all of this was accompanied with the recommendation I buy a much more expensive Midnite Solar MPPT controller that could handle a lot more input current.

After a call back from Schneider who confirmed my configuration is entirely acceptable I was relieved to hear them say that while it is true that I am wasting some power by not using an MPPT charge controller my configuration is just fine.

I know my configuration is acceptable but I don't have the money right now to reconfigure for 24V system and I wanted something that was compatible with all my existing stuff. I don't mind using 12V believe me.

Whenever you deal with the pseudo-experts at "Renewable Energy" retail outlets (and online in forums) make sure you double check every word that comes out of their mouths.

I am not going to mention any names but they are in Colorado, USA.

I am not able to afford an MPPT controller right now but when I do it will be Xantrx (Schneider Electric.)

Meanwhile I have only connected 3 panels to a spare Xantrex C40 and am charging the battery bank with just those three to get them fully charged.

Those (3) panels alone are producing significant power and I wanted to keep something on the battery bank as it had sat for about 1.5 months with no charge.

In a few days when I get the replacement charge controller I will re-wire everything again and see where I am at that point.

Let the above nonsense be a warning, watch out for idiots and trust in yourself.


I received the RMA charge controller today and connected everything. We haven't had much sunlight today so I can't really be sure the new charge controller is working. There was no burning smells or hissing so I guess that is a favorable omen. (Joking.) The most power I've noticed after I installed it was about 8.5A but the battery pack was already almost fully charged.

I will need to discharge the battery bank in order to really test the charge controller. I have not yet wired up the inverter/charger yet so I don't really have a way to drain the batteries easily. I might have some spare time this weekend to get that done.

Schneider stands behind their Xantrex products.