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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: steve5B on May 23, 2007, 05:42:38 AM

Title: AUX GENERATOR?
Post by: steve5B on May 23, 2007, 05:42:38 AM

I have a question, has anyone here tried to use a generator head of any size where the old ac compressor was.  Would it be possible to run it off of the belts of the removed compressor. 

I understand when you slowed the engine down while driving the volts would drop, would this cause problems or is it worth the time an effort put forth? 


Steve-5B
Title: Re: AUX GENERATOR?
Post by: H3Jim on May 23, 2007, 06:38:52 AM
My 50DN puts out more than enough current for anything I might meed to use while underway.  Since I have an inverter, I don't need to generate additional 110 or 220 while underway.  In addition, the main engine would have to be running for it to produce power, so for me anyway it would negate the main reason for having a generator - power while the bus is parked and the main engine is not running.  Certainly using the space to put your generator makes sense.
Title: Re: AUX GENERATOR?
Post by: DrivingMissLazy on May 23, 2007, 06:44:37 AM
Alternators are designed to operate at a specific RPM to produce 60 hertz output power. Typically 1800 or 3600 RPM.

If you couple it at a one to one ratio, then when your engine was at 1800 RPM then the alternator would be producing 60 hertz. If the engine slowed down to 1500 RPM then the output frequency would be 50 hertz. With the engine at 2100 RPM the output frequency would be 70 hertz. With a good (read expensive) voltage regulator the output voltage would probably remain within tolerance during the above excursions. However once you slowed the engine down to 1200 RPM or idle, then everything would quit. In other words, not really practicable.

There are devices on the market that try and control the output RPM of the alternator but the ones I tried never worked very good. Some have been installed on fire trucks and ambulances.

If I was going to try something like this I would look for a relative high speed DC output alternator that would operate in the 2,000 to 6,000 rpm range. At idle speed it would be close to 2,000 RPM and at maximum engine rpm it would be in the 6-8,000 range. The output of this device then fed into a battery bank and then to a high power DC to AC inverter.
Richard


Quote from: steve5B on May 23, 2007, 05:42:38 AM

I have a question, has anyone here tried to use a generator head of any size where the old ac compressor was.  Would it be possible to run it off of the belts of the removed compressor. 

I understand when you slowed the engine down while driving the volts would drop, would this cause problems or is it worth the time an effort put forth? 


Steve-5B
Title: Re: AUX GENERATOR?
Post by: TomC on May 23, 2007, 07:38:09 AM
There is a variable ratio (like a snow mobile belt drive variable speed transmission) drive that is used on boats to obtain 60 cycles from the main engine no matter what the rpm.  But-it doesn't react fast enough for shifting and such in a land vehicle.  As Jim said, the Delco 50DN or Leece Neville 200-300amp alternator through an inverter will just about power anything including one roof top A/C going down the road.  I have a 12v system and with the 300 amp alternator at its' 13.6 volts, that works out to 4080 watts.  If you have the 270 amp 24 volt, at 27 volts when running, that works out to 7290 watts!  Would highly recommend a good true sine wave inverter/charger since it also keeps your batteries up through its' three stage charger when plugged in.  Good Luck, TomC
Title: Re: AUX GENERATOR?
Post by: steve5B on May 23, 2007, 07:15:07 PM

  H3Jim, DrivingMissLazy, TomC.

   Guys, Thank you for the feedback and the info each one of you have stated.  I'll look and see what kind of AMPS it is putting out and take it from there!


Thanks again,

Steve5B