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citytosurf
04-02-2009, 12:18 PM
hey guys i am a new refrigdie just out of trade school and i just did my first call room unit change over evap and condenser and i need some help setting the tx valve super heat settings i have not worked much with tx valves i mainly deal with domestic stuff but the unit is the right size and when every thing is runnig fine it is ok i had a fue problems with leaks on the liqude like flare nut on the tx valve once i fixed that every thing was fine other then i then the evap was not fully frosted if i put more gas in it the peshers would not have been right so i ajusted the tx valve but know i think i have gone to far because the just rang back in said it is fluding back to the compress so how do i set the super heat please help thanks guys the unit is running on r404 medium temp

nike123
04-02-2009, 12:24 PM
What is TXV model #?

Also, read this (http://www.refrigeration-engineer.com/forums/showthread.php?t=11903&highlight=adjust) thread!

citytosurf
04-02-2009, 12:29 PM
not shore sorry i know i is the small danfoss mechanical with number 01 orifice

nike123
04-02-2009, 12:32 PM
not shore sorry i know i is the small danfoss mechanical with number 01 orifice

What is design evaporation temperature and cooling capacity of evaporator?

citytosurf
04-02-2009, 12:34 PM
1500watts design temp of the evap-6

nike123
04-02-2009, 12:53 PM
1500watts design temp of the evap-6

Then it is TS2 or TES2 if with external equalization.
Turn the adjustment screw counterclockwise until the end and then turn clockwise 3 turns (3x360°) if it is not Mop charge and 2 turns (2x360°) if it is Mop charge, to restore factory setting.
Then proceed with subcooling measurements to establish correct charge.

citytosurf
04-02-2009, 01:03 PM
what should the super heat be set to i think it is a ts2

citytosurf
04-02-2009, 01:04 PM
it is a internal valve with flare nuts

nike123
04-02-2009, 01:09 PM
what should the super heat be set to i think it is a ts2

Do not attempt to change superheat (other than I just told you) until you have correct charge, and cold room at or near design temperature.
When you readjust valve as I described, you will be having factory adjusted superheat. That superheat could be case, only if you have liquid only at entrance of TXV and cold room temperature near design conditions. In all other cases, you will be having higher superheat, no matter what superheat is adjusted at TXV.

Keep reading that thread i linked.

nike123
04-02-2009, 01:15 PM
what should the super heat be set to i think it is a ts2

Factory set superheat (also right one for your application) is 5K and it is adjusted as I just told you.

http://rc.danfoss.com/TechnicalInfo/literature/manuals/01/ri1ae300.pdf

citytosurf
04-02-2009, 01:19 PM
thanks alot for your help how menny degree td would you run between the evap and the food i wanna get the room sitting at about 1 or 2 dregrees what should my suction presher be around hey while i have got you what should i set my hp lp at i all ready have a t/stat that is the main contorl the hp lp is mainly for safty i was not shore where to set it

citytosurf
04-02-2009, 01:21 PM
what does mop stand for

Slatts
04-02-2009, 01:44 PM
maximum outlet pressure.
Try hitting F7 before you post city.

nike123
04-02-2009, 01:45 PM
thanks alot for your help how menny degree td would you run between the evap and the food i wanna get the room sitting at about 1 or 2 dregrees what should my suction presher be around hey while i have got you what should i set my hp lp at i all ready have a t/stat that is the main contorl the hp lp is mainly for safty i was not shore where to set it

Please format your sentences, it is hard to read without any formatting.


TD depend on evaporator construction and application. For your case it is important to know what humidity you want in cold room.
Pressure in evaporator is result of evaporator air in temperature and TD of evaporator. TD of evaporator could be adjusted with superheat change and air quantity at evaporator.
You need to ensure enough total superheat (evaporator superheat+ suction line superheat) to ensure that liquid cannot come to compressor. In the same time high evaporator superheat mean low humidity and inefficient evaporator.

citytosurf
04-02-2009, 01:52 PM
the room is at a restaurant. They have meat and vegetables in the room

Slatts
04-02-2009, 01:53 PM
Here city, download this (http://www.heatcraftrpd.com/resources/wiringdiagrams/H-ENG-2.pdf) and have a read. The units are all imperial but the info is good.

Ah, that's better. We can understand that.

citytosurf
04-02-2009, 02:02 PM
thanks alot that was a good help

nike123
04-02-2009, 02:27 PM
the room is at a restaurant. They have meat and vegetables in the roomThan best is to have high humidity which mean low TD of about 5K.

That mean 2°C room temperature - 5K TD = -3°C evaporation temperature (4,5 Bar gauge) but only when room temperature is 2°C and TD of evaporator is 5K

nike123
04-02-2009, 03:01 PM
what should i set my hp lp at i all ready have a t/stat that is the main contorl the hp lp is mainly for safty i was not shore where to set it

It should be set in way that pressure/temperature newer goes out of operation envelope of compressor.
For example, if operation envelope of compressor is -20°C/45°C than Lp should be set 4 bar gauge (cut out) and 1bar differential, and Hp should be set 21,5 bar gauge.

frank
04-02-2009, 09:27 PM
I don't want to start a war, but......

We have experienced fridge engineers emigrating to Auz that have to go back to college, study and then take exams before they are allowed to work in the Auz trade, (if they can get a place in college) and here we have a fellow, just out of college in Auz,(I assume a native of Auz) who doesn't appear to have even the basic understanding of the trade??

Am I missing something??

nike123
04-02-2009, 09:44 PM
[quote=frank;134414]I don't want to start a war, but......

We have experienced fridge engineers emigrating to Auz that have to go back to college, study and then take exams before they are allowed to work in the Auz trade, (if they can get a place in college) and here we have a fellow, just out of college in Auz,(I assume a native of Auz) who doesn't appear to have even the basic understanding of the trade??


Nobody forbid immigrants that, after exam, forget everything they knew.:D;)

Slatts
05-02-2009, 03:14 AM
I don't want to start a war, but......

We have experienced fridge engineers emigrating to Auz that have to go back to college, study and then take exams before they are allowed to work in the Auz trade, (if they can get a place in college) and here we have a fellow, just out of college in Auz,(I assume a native of Auz) who doesn't appear to have even the basic understanding of the trade??

Am I missing something??
He's from Victoria Frank. We make allowances for them.
We've just exported one of our X apprentices to Scotland. The stories he's sent back from there would turn my hair white... If I still had some;)