2 Stage compressor coil body not cold!

Hello every body ,

Today i face a problem with the 2 stage compressor . could anybody guide me how to solve the problem . That is freezer room -25°C . Your help would be much appreciate .

Compressor Model : Bitzer S6F-30.2Y-40P
Refrigerant use : R507
Condenser air in temperature : +33°C
Condenser air out temperature : +41°C
Evaporator air in temperature : -18°C
Evaporator air out temperature : -
Suction line at evaporator outlet : -
Liquid line at receiver oulet : +42°C
Temperature at compressor inlet : - 11°C
High side pressure at receiver outlet :290 psi (sct= 46°C)
Low side pressure at compressor :20 psi (sst= -27°C)

My problem is why i can't adjust the compressor coil cold ( condensation ) . I have measured the temperature at subcooler( Measured at outlet of subcooler where its back to compressor coil for body cooling ). The temperature was fractuated at +16°C to +20°C .The sight glass at subcooler not full but the sight glass at liquid line full .

Thank you

Regards
oilzee

what happen if the filter drier block at subcooler ? should i refill gas until sight glass full (at subcooler) to cold the compressor coil ?

today i went to the side to check the compressor again , its still the same ( compressor coil no condensation )
should i change the subcooler expansion valve ? Right now compressor running ampere is 20A .

I had same case before. You should refill gas until sight glass full (at subcooler) to cold the compressor coil and expansion valve of subcooler is not normal one if you want to chage it it shoud be same as old one.
+check filter + did you vacume it ((high vacume = 1 hour should be in vacume))
During refilling you can cool the condenser by water. it give you time to fill gas in low presure at discharge side and coil of compressor runs in normal temperature .

Quote:

---

Originally Posted by mbc

You should refill gas until sight glass full (at subcooler) to cold the compressor coil .

---

Thanks for your help Mbc . i don't understand why the sight glass at liquid line full but sight glass at subcooler not full . I am afraid some body has adjusted the expansion valve . I am the 3rd person to troubleshoot this system .As i know the compressor coil should be cold but do you know what is the right temperature at inlet of the coil ?

I wiil come back this everning to up date you . thank you .

regards
oilzee

Quote:

---

Originally Posted by oilzee

what happen if the filter drier block at subcooler ? should i refill gas until sight glass full (at subcooler) to cold the compressor coil ?

---

I'm agree wd you,Ihad same problem befor:cool:

Hello ,

today i face another problem ,that is refrigerant can't pass through that sight glass at subcooler .Its look like some where blocked. First of all i thought 3/8" filter drier blocked , so i changed it but once i test run after vacuum its still the same ( no refrigerant pass through ).
Then i quickly got another subcooler expansion valve orifice from other system ( Bitzer S6F-30.2Y-40P ) which is good one and chnged it .The result were same (refrigerant pass through ).
I still don't know where is the block ? expansion valve ? subcooler ( heat exchanger )? i am sure the solenoid valve is proper fuction when coil energized because i test for it .

Quote:

---

Originally Posted by oilzee

Hello every body ,

Today i face a problem with the 2 stage compressor . could anybody guide me how to solve the problem . That is freezer room -25°C . Your help would be much appreciate .

Compressor Model : Bitzer S6F-30.2Y-40P
Refrigerant use : R507
Condenser air in temperature : +33°C
Condenser air out temperature : +41°C
Evaporator air in temperature : -18°C
Evaporator air out temperature : -
Suction line at evaporator outlet : -
Liquid line at receiver oulet : +42°C
Temperature at compressor inlet : - 11°C
High side pressure at receiver outlet :290 psi (sct= 46°C)
Low side pressure at compressor :20 psi (sst= -27°C)

My problem is why i can't adjust the compressor coil cold ( condensation ) . I have measured the temperature at subcooler( Measured at outlet of subcooler where its back to compressor coil for body cooling ). The temperature was fractuated at +16°C to +20°C .The sight glass at subcooler not full but the sight glass at liquid line full .

Thank you

Regards
oilzee

---

Hallo Olizee,
I had attend the same problem in BITZER, In my case I stiped the compressor then checked-Suddenly raised suction line & Motor temperature . Then i changed the valve plate.Now it`s OK

Quote:

---

Originally Posted by Joy

Then i changed the valve plate.Now it`s OK

---

Hi Joy,

thanks for your help ,do you mean changed suction valve plate at the compressor ?

Regards
oilzee

Quote:

---

Originally Posted by oilzee

Hi Joy,

thanks for your help ,do you mean changed suction valve plate at the compressor ?

Regards
oilzee

---

Hi Oilzee
I changed the compressor Valve plate

had same fault found broken valves in comp

Please give me .
Suction Pressure - intermediate pressure -
also check the bulb of expantion valve to sits on pipe exactly it is very important

Quote:

---

Originally Posted by mbc

Please give me .
Suction Pressure - intermediate pressure -
also check the bulb of expantion valve to sits on pipe exactly it is very important

---

Hello

i just came back from side.Here the temperature i recorded .R507

condenser air in temperature : +30°C
condenser air outlet temperature : 39°C
Liquid line pressure : 260psi (SCT +41°C)
Suction line pressure at compressor inlet :12psi(SST-33°C)
Evaporator air inlet temperature : -17°C
Evaporator air outlet temperature : -
Suction line at evaporator outlet : -
Liquid line temperature at receiver outlet : +36°C
Discharge temperature at compressor outlet : +80°C
Suction line temperature at compressor inlet : 0°C
Compressor coil inlet temperature : +35°C
Liquid line temperature at sub-cooler outlet : +23°C

Liquid line Sight glass full but sight glass at sub-cooler not full ?

Thank you

Quote:

---

Originally Posted by martinw58

had same fault found broken valves in comp

---

May i know why the compressor valve plate easy broken ? Thank you

Quote:

---

Originally Posted by oilzee

May i know why the compressor valve plate easy broken ? Thank you

---

liquied or oil in top of pistons = liqied retrun from system or heater of comp. during of time does not work
too much oil in crancase ( compressor )

you have:
Suction line pressure at compressor inlet :12psi(SST-33°C)
Evaporator air inlet temperature : -17°
Delta T of those is too high it should be about 8
Refill gas then check again if is higher than 8 open Expantion valve (( system should be off))
Compressor coil inlet temperature : +35°C = is not too high

Quote:

---

Originally Posted by oilzee

May i know why the compressor valve plate easy broken ? Thank you

---

In my case there is a miner leak in valve .when the compressor stop with high head pressure then hot gas flow through valve to the suction side. Check the valve condition, Check-Refrigerant charge, Ex- valve, IF any Suction heat Exchanger, Motor Amps and Volt. Oil viscosity, crankcase heater…..
If it is possible, change set point temp -25`C to -22`C

Quote:

---

Originally Posted by Joy

In my case there is a miner leak in valve .when the compressor stop with high head pressure then hot gas flow through valve to the suction side. Check the valve condition, Check-Refrigerant charge, Ex- valve, IF any Suction heat Exchanger, Motor Amps and Volt. Oil viscosity, crankcase heater…..
If it is possible, change set point temp -25`C to -22`C

---

Quote:

---

Originally Posted by mbc

you have:
Suction line pressure at compressor inlet :12psi(SST-33°C)
Evaporator air inlet temperature : -17°
Delta T of those is too high it should be about 8
Refill gas then check again if is higher than 8 open Expantion valve (( system should be off))
Compressor coil inlet temperature : +35°C = is not too high

---

I am greatly appreciate all your help . I will do my best .