Reply
 
Thread Tools Display Modes
 
Old 12-28-2018, 02:21 PM   #1
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 301
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Truck Apu DC generator

I am kicking around the idea of getting a salvaged truck APU and using it for a generator. I am thinking that a large 12v or 24v alternator could be added in addition to the 120v generator or in place of it. If the set up correctly the engine rpm could be varied to provide the needed output currant/dc voltage. It would allow the engine to run more slowly/quietly for battery charging. If a larger DC load was placed on the system or 120v power was wanted the rpm could be increased. Most APUs are belt driven from the engine so swapping out components shouldn't be too hard. Has anyone tried this?

Ted
TJones is offline   Reply With Quote
Old 12-28-2018, 02:52 PM   #2
Bus Nut
 
Join Date: Nov 2016
Posts: 539
No, but would not do both.

A rectifier/PSU/charger from AC to DC, or an inverter to go from DC to AC are not expensive even at high amps.

KISS for moving parts stuff for sure.

Only advantage I see over a quiet little Honda is if you want to use diesel, same fuel as your bus.
john61ct is offline   Reply With Quote
Old 12-28-2018, 06:30 PM   #3
Bus Crazy
 
milkmania's Avatar
 
Join Date: May 2015
Location: Oklahoma aka "God's blind spot"
Posts: 2,357
Year: 1989
Coachwork: 1853FC International/Navistar
Chassis: 35' Retired Air Force Ambulance
Engine: DT466, MT643
Rated Cap: 6 souls and a driver
Quote:
Originally Posted by john61ct View Post
No, but would not do both.

A rectifier/PSU/charger from AC to DC, or an inverter to go from DC to AC are not expensive even at high amps.

KISS for moving parts stuff for sure.

Only advantage I see over a quiet little Honda is if you want to use diesel, same fuel as your bus.
agreed, I'd go this route personally
__________________
I once complained I had no shoes....
Until I met a man with no feet
milkmania is offline   Reply With Quote
Old 12-28-2018, 07:54 PM   #4
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 11,136
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
this guy has some good ideas, only real issue being having to carry gasoline.. actual truck APUs come in masny flavors from mild to wild..



some will connect to the truck's cooling system to keep the engine warm, or heat heating loops , some have as belt drivern A/C, others electric. every last one of them except maybe the newest most expensive are defimnitely not nearly as quiet as a honda generator.. in the trucking world, noise is no barrier.. trucks arent parked in RV parks or campgrounds where quiet-time is encouraged..



-Christopher
cadillackid is offline   Reply With Quote
Old 12-28-2018, 11:31 PM   #5
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 301
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Few generators are as quiet as Hondas. I would like to have just diesel for fuel. An APU would be louder but I don't think it would be too bad if it could be run at high idle around 1000 rpm vs the 1800 rpm to 3600 rpm needed for non inverting generators. I could use the heat from the APU coolant for heating the domestic water, interior or bus engine preheat. I will not be spending much time in RV parks so I wouldn't annoy anyone too much.

Ted
TJones is offline   Reply With Quote
Old 12-29-2018, 11:54 AM   #6
Bus Nut
 
Join Date: Nov 2016
Posts: 539
If you need to carry propane anyway, that's a **great** option for a small inverter genset, better than gas.
john61ct is offline   Reply With Quote
Old 12-29-2018, 11:10 PM   #7
Bus Crazy
 
Join Date: Aug 2014
Location: SW New Hampshire
Posts: 1,249
Quote:
Originally Posted by TJones View Post
I am kicking around the idea of getting a salvaged truck APU and using it for a generator. I am thinking that a large 12v or 24v alternator could be added in addition to the 120v generator or in place of it. If the set up correctly the engine rpm could be varied to provide the needed output currant/dc voltage. It would allow the engine to run more slowly/quietly for battery charging. If a larger DC load was placed on the system or 120v power was wanted the rpm could be increased. Most APUs are belt driven from the engine so swapping out components shouldn't be too hard. Has anyone tried this?

Ted
I floated an idea pretty much identical to this on the forum a while back and got crickets. I priced out a used Yanmar diesel APU engine, a 200A 24V alternator, and a (4? 6?) kw inverter for significantly less than I could find a similarly sized diesel genset. This would come with the additional benefit of charging a 24V battery bank which could feed the inverter when parked, etc.

Then I jumped down the rabbit hole of DIY lithium ion battery packs. That's a whole different story. But I'm on board with the idea.
dan-fox is offline   Reply With Quote
Old 12-29-2018, 11:32 PM   #8
Bus Nut
 
Join Date: Nov 2016
Posts: 539
Yes it can be done, for those who enjoy such projects and will be there to DIY the maintenance.

But IMO for most people an easy OTS solution is more practical, something breaks, buy a replacement
john61ct is offline   Reply With Quote
Old 12-30-2018, 01:46 PM   #9
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 301
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Quote:
Originally Posted by dan-fox View Post
I floated an idea pretty much identical to this on the forum a while back and got crickets. I priced out a used Yanmar diesel APU engine, a 200A 24V alternator, and a (4? 6?) kw inverter for significantly less than I could find a similarly sized diesel genset. This would come with the additional benefit of charging a 24V battery bank which could feed the inverter when parked, etc.

Then I jumped down the rabbit hole of DIY lithium ion battery packs. That's a whole different story. But I'm on board with the idea.
I came to the same conclusion you did as far as the pricing comparison between used diesel gen and apu. I've seen some fairly low hour salvage apu advertised for around $1500. Most were around 3kw. Many of them run 2 cylinder kubota engines rated from 9 to 13 hp. There are a couple that had 3 cylinder isuzu. It seemed the older models had perkins and yanmar.

The lithium will be a fun project.

Ted
TJones is offline   Reply With Quote
Old 12-30-2018, 01:50 PM   #10
Bus Nut
 
TJones's Avatar
 
Join Date: Jul 2017
Location: Rapid City, SD
Posts: 301
Year: 2001
Coachwork: Blue Bird
Chassis: CS RE
Engine: ISC 8.3 L 260 hp
Rated Cap: 36
Quote:
Originally Posted by john61ct View Post
Yes it can be done, for those who enjoy such projects and will be there to DIY the maintenance.

But IMO for most people an easy OTS solution is more practical, something breaks, buy a replacement
I do like projects! Your right for the average person it's better to be plug and play.

Ted
TJones is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:45 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.