Dollytrolley Posted October 29, 2017 Report Share Posted October 29, 2017 Graveyard shift hiding from memory-loss loss-mom-n-law so.........what better way to start a raging fire here on the forum that to talk..... electricity.... So you ever wonder how Huge the wires are leading out to those EIGHT inch +1,000,000 CP landing lights on large aircraft.......well the answer is......it is a tiny wire full of lotsa big current......400Hz AC then a small transformer just behind the bulb converts the 400Hz into voltage / amps required by the bulb......the weight savings is stunning...... 400Hz AC has other uses such as powering gyros at high speed without needing brush motors. Fast forward to our low tech toybox with a small high-tech fridge with a compressor controlled by a VFD (Variable Frequency Drive) the controller in the fridge VERY Sloooowly starts the compressor and then only turns the compressor just at the RPM needed to attain the desired cooling and not one RPM more......the power savings are silly-low compared to most Dumb-Fridges that start wide open and run wide open throttle.......very power wasteful..... So now that solid state VFD are so common that my cheep fridge has one it seems that some of the "$parky-Minded-Geeks" might offer some thoughts on how some uses for VFD's might save power in RV use???? Now one down side of High Freq AC is that it is Nasty stuff to get shocked by....don't ask me how I know...... Nasty stuff...... Drive on......(VFD'S........ shocking Kool) 97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S Link to comment Share on other sites More sharing options...
Steve from SoCal Posted October 29, 2017 Report Share Posted October 29, 2017 400 Hz power is great for airplanes where inductive loads are common consumers, not that many motors in an RV. I has a couple of CNC routers that had 400Hz (variable frequency drive) vfd inverters for the spindle drives, they were the ONLY application I have ever encountered where that was needed. I am a user of industrial VFD inverters and, for HVAC, refrigeration and , other motor loads they make sense. In an RV or really any DC based power system it would be nice to have DC primary bus VFD inverters to reduce conversion losses. An AC inveter takes mains power and rectifies it to DC then inverts it back to pulsed AC. That is how your fridge and new HVAC systems run. Another nice feature of VFD's is a soft start or ramp up instead of high inrush current typical of a motor starting. With the solar/wind energy field development a lot of efficiency improvements have transpired. Then electric motor technology has really made great leaps, perm magnet motors /BLDC are far better than more common induction AC motors. Look at the mini splits or package AC systems in comparison to an RV AC, they use less than half the power and are quieter. The cookie cutter RV industry will continue to use legacy equipment until consumer demand warrants a change. That doesn't mean we are stuck with it in custom or replacement systems. I went all electric in my Teton, I still have to source a battery bank likely a VOLT. I am far more comfortable with an all electric system from a fire and fuel consideration. An enormous amount of RV fires are propane related, yes the next most common are electric but, a distant second at best. Regarding fuel, it is just far less hassle to fill up at one point and be done. Not to mention the added storage space afforded the former propane bottle locker. Propane is an efficient heat source and has some merit, I just personally feel that it is not an energy source I want to employ in vehicles. Diesel fired heat is an attractive option I have considered but, not for this trailer. My current trailer is somewhat a prof of concept. As I have mentioned to Mike privately I have another project tentatively in the works. Steve 2005 Peterbilt 387-112 Baby Cat 9 speed U-shift 1996/2016 remod Teton Royal Atlanta 1996 Kentucky 48 single drop stacker garage project Pulls like a train, sounds like a plane....faster than a Cheetah sniffin cocaine. Link to comment Share on other sites More sharing options...
Dollytrolley Posted October 30, 2017 Author Report Share Posted October 30, 2017 14 hours ago, Steve from SoCal said: 400 Hz power is great for airplanes where inductive loads are common consumers, not that many motors in an RV. I has a couple of CNC routers that had 400Hz (variable frequency drive) vfd inverters for the spindle drives, they were the ONLY application I have ever encountered where that was needed. I am a user of industrial VFD inverters and, for HVAC, refrigeration and , other motor loads they make sense. In an RV or really any DC based power system it would be nice to have DC primary bus VFD inverters to reduce conversion losses. An AC inveter takes mains power and rectifies it to DC then inverts it back to pulsed AC. That is how your fridge and new HVAC systems run. Another nice feature of VFD's is a soft start or ramp up instead of high inrush current typical of a motor starting. With the solar/wind energy field development a lot of efficiency improvements have transpired. Then electric motor technology has really made great leaps, perm magnet motors /BLDC are far better than more common induction AC motors. Look at the mini splits or package AC systems in comparison to an RV AC, they use less than half the power and are quieter. The cookie cutter RV industry will continue to use legacy equipment until consumer demand warrants a change. That doesn't mean we are stuck with it in custom or replacement systems. I went all electric in my Teton, I still have to source a battery bank likely a VOLT. I am far more comfortable with an all electric system from a fire and fuel consideration. An enormous amount of RV fires are propane related, yes the next most common are electric but, a distant second at best. Regarding fuel, it is just far less hassle to fill up at one point and be done. Not to mention the added storage space afforded the former propane bottle locker. Propane is an efficient heat source and has some merit, I just personally feel that it is not an energy source I want to employ in vehicles. Diesel fired heat is an attractive option I have considered but, not for this trailer. My current trailer is somewhat a prof of concept. As I have mentioned to Mike privately I have another project tentatively in the works. Steve Steve, You bring up good points.... Judging by the lack of response to the subject of VF modification of RV electrical systems this subject is likely too far advanced for RV folks to wrap their minds around. Lithium batteries might be the leading edge for the several years (or decades) to come. VFD's are well accepted installed in many applications that we all use but not understood in primary use other than industrial applications. In the mean time, I will enjoy ice cold Dr Pepper from the VFD fridge that truly "idles" along on a tiny battery bank for days on end...... Drive on..... (VFD......too advanced for RV use?) 97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S Link to comment Share on other sites More sharing options...
Jack Mayer Posted October 30, 2017 Report Share Posted October 30, 2017 So, what fridge do you have, DT??? Jack & Danielle Mayer #60376 Lifetime Member Living on the road since 2000PLEASE no PM's. Email me. jackdanmayer AT gmail 2016 DRV Houston 44' 5er (we still have it) 2022 New Horizons 43' 5er 2016 Itasca 27N 28' motorhome 2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU No truck at the moment - we use one of our demo units 2016 smart Passion, piggyback on the truck -------------------------------------------------------------------------See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar powerwww.jackdanmayer.com Principal in RVH Lifestyles. RVH-Lifestyles.com Link to comment Share on other sites More sharing options...
Dollytrolley Posted October 31, 2017 Author Report Share Posted October 31, 2017 12 hours ago, Jack Mayer said: So, what fridge do you have, DT??? Hey Jack, The fridge I have has been superseded by another Frigidaire model that I have been told is also VFD compressor controlled. Had I known how Kool (pun intended) the fridge would be I would have bought a truck load of them. Many folks contacted me regarding the fridge and several reported that they loved the fridge as well. I am presently dealing with the memory-loss-mom-n-law so when I get a moment in a few days I will see if the replacement model has the same specs as the fridge that has served us so well. Many folks were turned off by the 11.5 C F size but the internal layout is amazing and we could put 3 gallons of Crown Royal and two-L of Dr Pepper in the door shelf (or milk) . The freezer was -10 f one day at Last Chance Peak when it was + 127 f in the shade and our toyhauler was not in the shade and the fridge just idled away with less than 3 amps load running only a few minutes once in a while. I am told that IF the dealer finds out that fridge is installed in a RV that the fridge coverage is void but at $445 for three years of fairly intense service this fridge is now paying me to keep things kool........ Get the new model number for you soon.... Drive on.........(low current cool is........kool) 97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S Link to comment Share on other sites More sharing options...
Jack Mayer Posted October 31, 2017 Report Share Posted October 31, 2017 Thanks DT....no hurry on the fridge info..... Jack & Danielle Mayer #60376 Lifetime Member Living on the road since 2000PLEASE no PM's. Email me. jackdanmayer AT gmail 2016 DRV Houston 44' 5er (we still have it) 2022 New Horizons 43' 5er 2016 Itasca 27N 28' motorhome 2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU No truck at the moment - we use one of our demo units 2016 smart Passion, piggyback on the truck -------------------------------------------------------------------------See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar powerwww.jackdanmayer.com Principal in RVH Lifestyles. RVH-Lifestyles.com Link to comment Share on other sites More sharing options...
Imurphy907 Posted October 31, 2017 Report Share Posted October 31, 2017 I would love to see Dometic or someone like them to implement Inverter(VFD) technology to an RV AC unit. 15,000 BTU Inverter drive AC heat pump with stand alone condenser and evaporator fans. Using communicating thermostats vs on/off T stats. It would be like putting a mini split on the RV, except it would be OEM. RV AC units are the 2nd worst thing about the RV industry. The first being the power converters they call "battery chargers". It would not save any power when its 100% out and they are running full tilt. But between 80 and 20 it would equate to a much more comfortable RV(temp and noise) and prevent the hammering of the power system with the on off BS. Would also make it much easier to run off of self contained power be it generators or onboard battery driven inverters. 2016 Road Warrior 420 2001 Volvo VNL 660 Alaska Based. Link to comment Share on other sites More sharing options...
MsChrissi Posted November 1, 2017 Report Share Posted November 1, 2017 Sounds kind of like the Whirlpool fridge we just installed, 11 CF also and rated at 39watts. That's barely a glow in the light bulb world. Nice thing is it still uses condensing coils in the rear which means the RV fridge plenum can do it's thing, most compact imports use condensing coils imbedded in the skin all around and require inches of clearance for air circulation. Link to comment Share on other sites More sharing options...
Dollytrolley Posted November 2, 2017 Author Report Share Posted November 2, 2017 On 10/31/2017 at 6:25 AM, Jack Mayer said: Thanks DT....no hurry on the fridge info..... Jack, Still not been able to get to the RV component file yet but do have some notes from our fridge search a few years ago and I Think this is the unit we have in the toyhauler... Make: Frigidaire Model: FFTR1222QB Max Load (running): 0.8 to 1.5 My motor geek friend played with the fridge with his Flukescope and measured insanely low current runs with very low compressor runs and vast periods no elec use at all.... He left the Flukescope on the fridge for a couple days and when he played the traces back it was amazing how tiny the current use was.....way below the max listed and it was hot and we opened the door a lot.... Chuck contends that the normal FULL throttle starts and FULL speed compressor runs have been robbing fridge owners since the first fridge was sold... Drive on.....(low current.....high Kool) 97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S Link to comment Share on other sites More sharing options...
Imurphy907 Posted November 2, 2017 Report Share Posted November 2, 2017 The residential 24 cu ft LG in our trailer is inverter tech also. I watch the inverter display alot and have never seen it over 400 watts output. Not saying it does not go higher as i'm sure after stocking it up we put a hurting on it. But it runs for 3 days on two gr 31 rv/marine batteries with a xantrax 2000 w inverter. 2016 Road Warrior 420 2001 Volvo VNL 660 Alaska Based. Link to comment Share on other sites More sharing options...
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