Western Railroad Discussion > Refrigerator car cycling

Interesting discussion on refrigerator car cooling units at http://model-railroad-hobbyist.com/node/15205

Do mechanical reefers' cooling units and their diesel generators cycle on and off, or do they run constantly?

Surely someone here knows the correct answer.

(edit) I'm most curious about 1970s operations.



Edited 1 time(s). Last edit at 09/11/13 11:47 by grahamline.

I can't speak for the older "built in" refigereation units, but the modern "truck style" units will cycle between high speed, low speed and off.

junctiontower Wrote:
-------------------------------------------------------
> I can't speak for the older "built in"
> refigereation units, but the modern "truck style"
> units will cycle between high speed, low speed and
> off.

The older cars used Detroit 2-53 or 3-53 series 2 stroke
engines which ran constantly, think city buses!
The modern more fuel efficient units work as junctiontower
mentioned!!
Mike

It all depends on the load. Produce, meats, and other commodities have specific temperatures that they have to be keep at for the duration in which they will be transported. Modern day reefers, Thermo King and Carrier reffer units which are found on refridgerated rail cars, Have the ability to be controlled remotely by the persons who is using that car and unit. The reefers send data and the ambient temperature and internal car temperatures. They can see the amount of fuel that the car has, and any mechanical issues that may come about during the trip. Giving the rail carrier and customer the ability to keep track of their loads condition over the rail and fix a problem before it ruins the load. Ingersol Rand diesel engines are what I saw the most when dealing with thermo king units, effiecient and easy to maintain. So the simple answer to your question, is that the reefer unit is cyled through high and low rpms on the unit and on and off if mechanical problems arise or the temperature is effecting the load.

Attached is a picture of the PLN type diesel engine in a Thermo King SB-210.



Edited 1 time(s). Last edit at 09/11/13 19:26 by TaylorUPBNSF.

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Maybe it's both -

The generator could be running the whole time to provide power, but based on temperature, the A/C unit (if you want to call it that) would switch on/off.

BTW, Here's a photo of a Trane A/C unit, sorry it's not a better shot.

The photo is from a 1958 ATSF reefer.

Dan Quiat

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I remember seeing a GM 2-53 engine, and nearby was an SD 45 with a V20-645. The alpha and omega of GM diesel power at that time.