solar power ? or are they more suited for generators?
ie in a motor home situation
Plendo said
06:20 AM Jul 17, 2013
Hi Milo,
I have been researching this topic for a long time, and am convinced it is possible to run a reverse cycle air conditioner from an invertor, however the roof top RV units are not very well suited as they are old style non inverter units.
The roof top RV units I am aware of control the temperature by running the compressor until the temperature drops, then stopping the compressor (fans keep running), then when the temperature rises again they repeat the cycle. The motors only run at one speed (controlled by mains frequency), and are typically hard to start. As an example the Air Command Ibis that I am optioning out of my caravan has a running current of 5.9A, and a quoted starting current of 20 amps. At this sort of drain it would need a huge inverter, and battery to run it.
I am going to run a Fujitsu Split system with inverter drive. What the inverter means here is that the incoming 240V power is rectified to DC, then inverted back to AC but at the frequency the motor needs to run at to maintain the required temperature. Yes it means the motor basically runs all the time but often at a very low speed, and with a very low current drain. It also means the motor can be started gradually, thus reducing the current required to start it. The unit I am going to run requires 2.8A running current, with a maximum current requirement of 6A.
I will be feeding my unit from a low frequency pure sine wave inverter. It is important that it is low frequency as they have a physical transformer, and can handle much higher overloads for longer periods, this means you can reduce the basic size of the inverter. I will be feeding my inverter with DC from a large lithium battery, which I will charge using a number of light weight solar panels glued to the roof.
I hope this vastly simplified explanation helps.
Keith19837 said
10:50 PM Jul 17, 2013
G'day Milo, I'm running a Heron 3.0 (in wall) older type from a 3kw inverter from a 24 volt system (4x 12 volt batteries.) I have found that it drags power at start up (as was mentioned by Plendo) which almost left me red faced when the truck motor only just turned over when trying to drive off. I now run it off either mains or a modified wave generator (pure sine wave is better). Mine is a pre Y2K unit which may/may not make a difference. Collyn RIVERS has a website (and a couple of books) on this type of subject. From memory, go to Google (or similar) and type in Collyn Rivers Articles. Hope this helps.
can a motor home heater/conditioner be run from
solar power ? or are they more suited for generators?
ie in a motor home situation
Hi Milo,
I have been researching this topic for a long time, and am convinced it is possible to run a reverse cycle air conditioner from an invertor, however the roof top RV units are not very well suited as they are old style non inverter units.
The roof top RV units I am aware of control the temperature by running the compressor until the temperature drops, then stopping the compressor (fans keep running), then when the temperature rises again they repeat the cycle. The motors only run at one speed (controlled by mains frequency), and are typically hard to start. As an example the Air Command Ibis that I am optioning out of my caravan has a running current of 5.9A, and a quoted starting current of 20 amps. At this sort of drain it would need a huge inverter, and battery to run it.
I am going to run a Fujitsu Split system with inverter drive. What the inverter means here is that the incoming 240V power is rectified to DC, then inverted back to AC but at the frequency the motor needs to run at to maintain the required temperature. Yes it means the motor basically runs all the time but often at a very low speed, and with a very low current drain. It also means the motor can be started gradually, thus reducing the current required to start it. The unit I am going to run requires 2.8A running current, with a maximum current requirement of 6A.
I will be feeding my unit from a low frequency pure sine wave inverter. It is important that it is low frequency as they have a physical transformer, and can handle much higher overloads for longer periods, this means you can reduce the basic size of the inverter. I will be feeding my inverter with DC from a large lithium battery, which I will charge using a number of light weight solar panels glued to the roof.
I hope this vastly simplified explanation helps.
G'day Milo, I'm running a Heron 3.0 (in wall) older type from a 3kw inverter from a 24 volt system (4x 12 volt batteries.) I have found that it drags power at start up (as was mentioned by Plendo) which almost left me red faced when the truck motor only just turned over when trying to drive off. I now run it off either mains or a modified wave generator (pure sine wave is better). Mine is a pre Y2K unit which may/may not make a difference. Collyn RIVERS has a website (and a couple of books) on this type of subject. From memory, go to Google (or similar) and type in Collyn Rivers Articles. Hope this helps.
For what it's worth.