The Inverter Is In, And It Works!
To answer a couple of questions first raised in the comments forms, as soon as this old goat learns how to send pictures with the text I will get photos in the blogs.
As far as how I figured how much current that I wanted from my installation, the answer is simple. I figured that this would be the first phase of the installation and that if I could cut generator use by at least 50% I would be happy. The second requirement was that Lucy could plug the coffee pot in when she got up in the morning without firing up the generator. She has the feeling that when firing the gen set up in the morning that it will disturb my beauty sleep, and god knows I need all the Beauty sleep that I can get. She forgets that I take the hearing aids out when I am in bed and without them I can’t hear the generator, as it is up front on a Foretravel.
Now I could go through all the numbers that I ran, but basically I increased the battery capacity from 225 amps hours to just a tad under 1250 amps hours. The term amp hour is a measure of the capacity of a battery. 225 amp hours means that the battery should be able to deliver 225 amps (units of power) for one hour or one amp for 225 hours before reaching a voltage (pressure) that is considered a dead battery. Usually around 9 or 10 volts. With the available 1250 amp hours available I should be able to run both furnaces about 85 hours. Since the furnaces run about half time when the outside temperature is near freezing, making 170 hours of heat for 85 hours of battery drain.
The microwave draws 65 amps of twelve volt power to run the inverter and make the 120 volt current to operate. Typically the microwave is run 2 minutes to reheat and 10 minutes or so for a frozen meal. So given all the figures that I compiled on the spread sheet I figure that the battery pack alone will run the coach for 4 or 5 days and add the solar gain that could stretch to well over a week.
Under ideal sun conditions the system that I installed will give back 100 amps per day. I figure that will be about 40% of what I need to recharge the batteries over the long haul. The inverter/converter/charger that I installed has a 100 amp charging rate, charging the batteries faster using less generator time and fuel. Now another factor is that if we move several hundred miles in a weeks time the engine alternator will bring the batteries up as the engine alternator is a 125 amp unit. I bought the package from RV Solar Electric in Phoenix Arizona because it more closely matched what I wanted for power than anything else that I found.
The last quest was a two parter, what did I find as an auxiliary circuit breaker panel and where did I mount it. The panel was purchased at Home Depot and is a Square D 6 bay unit 12 circuit model HOM612L100SCP for under $20.00. The auxiliary circuit panel is mounted under the bed beside the main panel with 10 gage romex running up to the inverter and back. The output circuits, 2 legs, are protected by a pair of 30 amp breakers in the main panel and then six thirty amp breaker in the auxiliary panel form all the plugs and stuff. There was one more question about a progressive surge protector being hard wired into the system. To be honest I did not consider a surge protector when putting this rig together, but it is a good idea.
As to where did I put the batteries and the inverter? That is where the rub comes in. We drive an older Foretravel by choice. The older Grand Villa’s were a low profile rig. I have a walking disability and stairs are a problem. When we were looking to get out of the front engine Southwind and into a Diesel Pusher I began counting steps. The Southwind had two steps outside and three inside. That may not seam like much to those with no problems but for me the more steps the fewer times in a day that I can negotiate them. Some of these new rigs have six or more steps to get into the living compartment. The Foretravel is three steps from the ground onto the main floor and does not need outside steps.
The problem with a low profile is the reduction in the height of the storage bays. To install this system we lost one complete storage bay, the one in front of the center entrance door where the six Trojan golf cart batteries and battery tray takes a footprint of 24 inches by 27 inches. The height of the batteries leaves just enough room over the batteries to make the connections and service the batteries. The converter/inverter/charger mounts in the same cabinet and it does allow room for a shelf over it.
Now the system has been up and running for two days as a stand alone. Yesterday I was doing some rewiring on my car trailer lights and had the lights on on the coach. I had the Aux switch on connecting the engine battery into the system. The solar pumped away all day and the batteries registered 13.4 volts at the lowest. Today it is raining and cool meaning that I need to turn the coach heat on to get the freezer to work as we are loading up for an early Saturday take off for the grand Adventure. Even in the rain the solar is producing energy and the battery voltage is in the 13 volt range. It works.
The next installment will be from somewhere on the Lincoln Highway in Pennsylvania.
Brad & Lucy aka The Geezer and the hedgehog, and oh ya Earl the Kitty Kat.