APU

[Michelle]

I installed a Thermoking TriPac APU in my 86 LTL 9000 so I could run the air conditioning without running the truck engine all night. It was a used unit I bought from a friend in Iowa. It is electronic controlled with a automated circuit board that automatically starts the engine and maintains the desired temperature. The circuit board was fried and my friend told me about that before I got it from him. I still wanted it as I figured I could convert it to an electro mechanical unit without much trouble. I rigged up a temporary control board before I ever installed it on the truck to make sure it would run and it did run. I mounted it on the frame rail under the sleeper and with everything connected I vacuumed the A/C system down and surprisingly it held the vacuum. It has been holding it about three or four days now. I started it Friday to let it run for a little while before charging the A/C system and it ran about fifteen or twenty minutes and quit. I have the low oil pressure switch and the high water temp switch wired to the ground side of a single pole double throw relay so it will shut down in the event of low oil pressure or an over temp situation. It has no heat gage. Suspecting one or the other I used my infrared thermometer and pointing at the over heat switch in the thermostat housing, I restarted the unit and monitored the heat. Sure enough it closed the circuit at 200 degrees. It was four thirty Friday afternoon and I called the Thermoking in Austin and ordered a new thermostat. Their UPS driver had already been by so it was sent out today and I should have it by tomorrow afternoon. Hopefully this is going to fix my problem. Tomorrow afternoon I will post again and let you know what happened.

[foodstick]

I can already tell you what happened.. I am sitting here feeling insignificant !

Great work, you will get it no doubt

[Gritsngumbo]

Sounds great Michelle. Just wish I knew what you were talking about. I'm almost as confused as reading a post between Alan and Leeroy

[thenephilm]

I like lamp

[ezernut9mm]

i know what an apu is, but after that, ms. michelle, you done stumped this gear jammer. lol

[foodstick]

Isn't APU the guy that runs the slurpy mart on the Simpsons?


Thank you, come again...

[Michelle]

The APU is a small two cylinder diesel engine that runs an air conditioning compressor and a 65 amp alternator. I have a sleeper on the truck and if I choose to sleep in the truck in the summer months I want to be cool. So I start the APU and run it instead of the truck engine. The APU will run the A/C all night on a gallon of fuel or less. With the A/C running you have the blower motor for the A/C evaporator running, the condinser fan motor running as well as the radiator fan motor for the APU running. The APU belt driven alternator keeps the truck batteries charged so you don't wake up to a dead battery the next morning. The APU is the unit between the fuel tank and the tool box. Sorry I didn't make myself more clear the first time.

[JojoDVM]

I wanna be just like you when I grow up...

[slick4x4]

The APU will run the A/C all night on a gallon of fuel or less.

...........
You mean on less than a gallon per hour me thinks ......

[ezernut9mm]

naw, those apu's are real efficient. heck a big diesel will use a gal an hour.

[Michelle]

They are very fuel efficient, that can run eight to ten hours on a gallon vs ten to twelve gallons if you leave the truck engine running. Also if you leave the truck engine running you have to idle it up to about twelve or thirteen hundred RPM which burns even more fuel. A new APU cost eight to ten thousand dollars, but at four dollars a gallon for fuel times ten or twelve gallons a day idling can mount up a thousand dollars a month, you can see where these units can pay for themselves in less than a year. I have only about a thousand dollars in this one. Another point is that many cities have idling laws and will not allow a truck to idle over fifteen minutes without being ticketed.

[Gritsngumbo]

Thanks for the "learnin'" Michelle. Didn't know about them. An old guy in our local car club says when he wakes at night up from being too hot, he turns the engine on for a few minutes.
This seems to be much more desirable.

[Max]

I want to put one on my Slick just so I can take it out to the airport and tell everyone my Slick has an APU.

[Michelle]

I want to put one on my Slick just so I can take it out to the airport and tell everyone my Slick has an APU.

You can tell them, I have an APU, I am now able to start my own engine in remote areas with out external assistance.

[ezernut9mm]

You can tell them, I have an APU, I am now able to start my own engine in remote areas with out external assistance.

[Alan Mclennan]

Oh I understand completely!.................grits is having a dig at me and Leeroy!!!!

[jwh f-100]

Dont see those up here. Just see Webastos & Espars.. Same idea but fuel fired boilers..

[BigMike]

Just make sure you got good pressure on the whatchamacallit and good current on the thingamajig.

[Alan Mclennan]

Mike, you sound like your up to speed on these thingo`s!

[Michelle]

I did exactly as Mike said and it is now running perfect.