Md-II 50 SR info

[xeonpro]

I have been looking online for any info, brochures about this unit and have come up empty handed.
Can someone tell me specs on this unit?
I gather the "50" means it can be plugged in vs "30" not being able to.
Can it handle deep frozen? And what time frame was it manufactured?

TIA for any info!

- I'm looking at a used '03 truck from Ryder that has this unit on it.

[Robert Hilton]

Check the serial number. The first three tell the month and year that it was manufactured eg; 099 would (or could) say the ninth month of the ninth year. which decade requires more knowledge of when the units where available.
Deep frozen would be alot to ask of an MDII. They had the least capacity of the over-cab range. They can be used for it but will require good load/unload discipline to retain the temperature.

[xeonpro]

Thanks for the reply...not exactly what I wanted to hear lol...
My plan was to put a bulkhead (vented or with a thermostatic fan) about 6' back from the front, to keep ice cream up there, accessed from the side door then refrigerated product behind it such as pies and farm fresh veg.



The company I work for makes our own ice cream and we try to source as much vegetables as we can from local farms for our 15 restaurants, what we can't source gets delivered through one of our purveyors

[tony2009]

There are a number of factors which determine what unit will be best for a given application. The MD-II SR is a great unit and yes you are correct 50 means with standby and 30 means without. Assuming the unit is running on R404 and providing the construction of the body is suitable for frozen applications and door openings are such as to allow the goods to remain frozen, then there shouldn't be an issue with the MD-II SR unit handling frozen goods.
People often ask which unit is best for frozen, but in actual fact it relates to a variety of issues, rather than just the unit itself.

[tony2009]

I forgot to mention body size as well the body construction. Robert is correct in that the MD-II is amongst the smaller units in the self powered range and having said that, assuming that all the variables fall into place, then yes, the MD-II SR unit should be o.k.

[tony2009]

If you want to let me know the specs of the body you want to use it with I can let you know whether it should be suitable. To give you an example, if you were specifying a unit, you would look at external length, width, height, body construction type (ie material and thickness), ambient temperature range, unit operation hours, number of door and number of door openings along with the weight of the product. Hope this is what you were looking for. Please let me know if you want more info.

[xeonpro]

The Body is 18' Morgan, not sure on thickness of wall yet, waiting to hear back from Ryder on that. As I mentioned earlier I only need for 6' or so of it to be deep frozen. I'm from nh so ambient temperature rarely gets into the 90s (except last week!) it has a roll up rear door (not the best for temperature regulation I know) and a curb door within the first 6' of the body.

[xeonpro]

http://www.usedtrucks.ryder.com/Vehicle/VehicleSearch.aspx?VehicleId=959650

[tony2009]

Based on what you've told me and what you haven't, plus the many variables available and considering the closest I have specs on in terms of capacity would be the MD200, I've made a number of assumptions. Working on a body of approx L18'xW7'xH6.5' with a wall thickness of approx 4" made of fiberglass and assuming that of the 2 doors, the rear is opened around 10 times a day and the side around 20 times a day with a load weight of approx 8800lb (height or length of load doesn't matter), with the unit operating around 10hrs a day with ambients of between 23 and 50F; without door switches or curtains then something like an MD200 would be suitable; though with the rear door being a roller (assuming it's a Toddco or Whiting (or similar) insulated door, then this will have an effect on the overall ability of the unit to achieve deep frozen. Deep frozen being around 23 - -20F.
Remember that the calculations take in the whole area to be controlled which is classified as a compartment and assuming that the product is frozen prior to being packed into the body.
Hope this has been useful, but you will of course need to check the variables to ensure they fall in around these if you are looking at deep frozen. If I had all the information, I could have been a little more precise but hope this helps anyway. Let me know if you need more info. Regards; Tony

[xeonpro]

Thanks for the information! I would be installing side and rear door Strip curtains. Your input makes me more at ease, thank you. Havnt found another truck with under 230k miles for that price, I assume it's because of it only being an md-II. While all the other trucks of that vintage are running ts-300s.

[tony2009]

No worries, I normally work in metric but have no problem working with imperial measurements as well.
Can I suggest, that you might like to also check out http://reefertek.com/tektalk/ as this is also a very handy site considering the information you are looking for.
I'm more than happy to help where I can. If you don't mind me asking, what part of the US are you operating in as I have friends in various parts of the US, most of whom are involved in the transport refrigeration industry, who might be able to help with area specific information.
Regards; Tony

[tony2009]

Personally, I'm not a big fan of scroll compressors in transport applications, but that's me, we all have different viewpoints on that subject. For me, I would stay with reciprocating compressors in preference and there's nothing wrong with a properly maintained MD-II, they've got a good heritage; the TS series are still developing theirs.
The X214 compressor is a quick and easy rebuild should anything go wrong, compared to the scroll.
The TK reciprocating compressors have been around for many many years and are a proven and reliable piece of equipment, whilst the MD-II series as such has been around since the mid eighties making them a very reliable unit; in my opinion, it's very hard to go past something like that.
Overall, the MD-II units are very straightforward regardless of which variant it is.
As mentioned, it's not just the unit but a combination of the variables that will determine whether the unit will be suitable for the application.