August 1 – 31 2010 Inverter and Solar installation
I decided to upgrade our 2010 Lance 1685 travel trailer to include an inverter to power our microwave and accessory outlets. We have two Honda EU2000I generators but you can’t always use a generator when you want to in a campground and we are usually dry camping since our background is originally tent campers who moved up to pop up tent trailers prior to getting our first travel trailer. I was going to only install an inverter since the trailer already had a charger built into the power distribution center but it was hard to find an inverter without a charger in the wattage (size) I wanted to use.
While doing my research I decided that by installing an inverter/charger, I would end up with a better quality charger that was more efficient in charging the batteries since it would be connected with larger cables and installed within two feet of the batteries. Trying to power the A/C with an inverter was out of the question so since the microwave was the next largest load and is rated for 1050 watts I chose the Xantrex Freedom HF1800 modified sine wave inverter/charger and it has worked fine.
In making the decision to install the inverter, I also decided to upgrade the batteries from two 12 Volt (parallel) to two 6 Volt (series). This provided over 30% more Amp Hours available as well as having batteries with much heavier plates in them for better deep cycle use. The one area where this design was lacking was a way to feed power into the batteries that the inverter would quickly use up, without having to run the generators on a daily basis.
A Trimetric 2020 power meter that we installed in April 2010 helped us gauge our pre-inverter power usage while dry camping at 20 Ahrs per day. With the addition of an inverter, we could easily double our usage rate to 40 Ahrs per day. Solar panels were the answer. Solar charging the batteries will be quiet and automatic.
List of Components:
- Xantrex Freedom HF 1800 Inverter Charger - $619
- Kyocera KD135SX-UPU 135W 12V Solar Panel J-BOX - $417 each
- CW Combiner box for fridge vent - $40
- Unirac 990013 RV Rack w/ Folding Tilt Legs - $68 each
- Blue Sky Solar Boost 2512iX 25A,12V 3 Stage Charger with Remote IPN Panel- $420
- Interstate 6 Volt Battery with Box - $155 each
- Cable, Breakers, Switches, Fuses, metal fabrication, panel installation, tools, etc - $1560
- Panel installation by service center - $440
The
front storage compartment of the trailer was chosen to hold the inverter, solar controller, and switch/fuse circuitry. This location was as close as possible to the batteries, and protected from the weather.
The first step was to remove the shore power input from the power distribution center inside the trailer and using a junction box and 10 gauge cable, extend the power cable up to a circuit breaker box in the front storage compartment.
This breaker box fed into the AC input of the inverter and then another cable was run from the AC output of the inverter back to the power distribution box and connected so the same power distribution designed into the trailer could be reused. The power leads to the old converter in the power distribution box were removed and capped to that it can be used in the future if required. The Freedom HF 1800 has an automatic power transfer switch built into the unit.
The second step was to replace the old 12 Volt batteries with the new 6 Volt Batteries. This required building a new battery rack to allow enough space to add a small box in the center to house the 12 Volt cutout switch and the shunt from the Trimetric 2020 power meter.
With the new rack in place, cables were measured and installed from the batteries to the front storage compartment for connection to the inverter and solar controller. The shortest route was to drill two holes into the front of the trailer behind the batteries. Plastic through hull fittings from my local boat shop allowed the entry points to remain sealed.
An access hole was cut in the front storage compartment wall to allow access to the front of the trailer where the battery cables came through.
2/0 battery cables were measured and installed to connect the batteries, battery bank cutout switch, Trimetric meter shunt and also to feed into the Inverter/controller panel. Through hull fittings were used in the center switch box for entry/exit of the cables due to the difficulty in bending cables of this size. The DC input cables to the trailer distribution panel were also connected in this switch box.
The third step was to build a panel to install in the front storage compartment which would support the Solar panel controller and Inverter. This panel contained the 12 VDC cutout switch and 250Amp DC fuse for the Inverter, as well as the Solar Controller and circuit breaker panel (20 Amp for Panel input & 30 Amp for controller output to batteries).
Two 400A Blue Sea feed through terminals were installed in the panel to connect the battery cables (on the back side) to the inverter and controller (on the front side).
A 6 gauge ground wire was run from the panel to the trailer chassis ground. The panel was installed over top of the access hole that was cut in the storage compartment wall.
With the AC circuit breaker box installed along with the DC control panel, the forth step was to install the inverter in the front storage compartment. More 2/0 power cables were measured and cut to connect the inverter to the feed through terminals on the DC control panel and a 6 gauge wire measured to connect the inverter ground to the trailer chassis ground on the DC control panel. A wire shelf was cut to make a cage surronding the inverter for protection.
The Xantrex Freedom HF 1800 control panel was removed from the inverter and remotely installed inside the trailer between the Trimetric 2020 power meter and the original Lance Systems Monitor Panel. This allowes ease of use in turning the Inverter on/off as required, as well as monitoring the power usage gauged by the Xantrex remote panel which can be compared to the Trimetric meter results to the left of the Xantrex remote panel.
The fifth and final step was to wire in the solar panels. A combiner box was installed on the outside of the fridge vent on the roof of the trailer.
This allowed the use of 6 gauge cable to be run from the combiner box, down the fridge vent to the back of the fridge access hatch and down from the access hatch to the front storage compartment along the same route as the shore power cable and then connected to the solar controller.
As a compromise with my better half, I agreed to have a service center install the panels on our Lance travel trailer to ensure that water tight integrity remained in the roof; a small compromise considering we will now have an inverter and solar charging system installed in our trailer. Since we live within 2 hours of the Lance manufacturing facility in Lancaster, CA, I chose to have their service department install the panels because they have access to all the diagrams of wiring runs for the trailer roof.
We had two Kyocera
KD135SX-UPU 135W 12V Solar Panels with J-BOX's installed on Unirac 990013 RV Racks w/ Folding Tilt Legs. This allows us the option to tilt the panels if desired, or use them flat on the roof.
One panel was installed on the front left corner of the trailer.
The second panel was installed on the rear right side above the entry door.
8 gauge wire was used to connect the panels in parallel to the juction box on the fridge vent cover.
I realized that in order to program the solar charge controller, I would need to use a Blue Sky IPN remote panel. I purchased one and installed it in place of my Trimetric 2020 battery meter. I had to upgrade my 100A shunt to a 500A shunt in the process to account for the new inverter draw from the batteries. The IPN remote gives me the battery use monitoring capability while also letting me program the solar controller for proper charging voltatges during bulk, absorption, and float stages of charging as well as other functions.
During our first use of the system, the panels produced 11.7A per hour in full sun (10AM to 2 PM) with the panels flat on the roof. I will do some experiments with tilting the panels in the future to see how much of an increase I can gain. Overall, this upgrade has been worth it for us to have the availability of the microwave and convenience outlets all the time while boondocking, and the charging power from the panels to pay the debt back to the batteries while never disturbing the peace and quiet.
After using the system, I found out that I could no longer power my A/C unit with my generators. Research found that the inverter's automatic transfer switch would see a drop in the power from the generators when I would start the A/C and the inverter would automatically try to switch to inverter mode instead of waiting for the generators to speed up to produce the required power for the A/C. To solve this problem, I installed a circuit breaker subpanel in place of the junction box intially installed under the sink and removed the A/C and electric water heater circuits from the power distribution panel that is fed by the inverter.
This was the junction box I originally installed to reroute the shore power input from the power distribution center directly to the inverter/charger.
This is the replacement circuit breaker subpanel that serves as a junction box to route shore power to the inverter/charger, and also sends shore power directly to the A/C and electric water heater so the units do not draw power from the inverter circuit. The generators are now able to run the A/C and electric water heater if desired without causing the inverter's automatic transfer switch to engage.
***UPDATE 11/29/11***
Added an additional breaker into the subpanel for the refrigerator and moved the circuit from the inverter feed to the shore power feed. Although the inverter could power the refrigerator, the draw was too much for the batteries over a long period of time. My concern was that when the trailer loses shore power, the inverter by design automatically comes on to keep providing AC and if the refrigerator is set to AUTO, then it starts to draw from the inverter. If I was using shore power, the power dropped, and I was away from the trailer, the inverter would begin producing AC and the refrigerator would kill the batteries. At this point, I am running the refrigerator (AUTO), A/C, and electric water heater directly off shore power, and only the microwave and accessory outlets off the inverter. If the power drops and the inverter automatically comes on, the refrigerator will switch to propane mode and there is no load on the inverter big enough to worry about if I am gone for awhile.
