ult -95 degree

[edi]

hai,
anybody can help me,
i had a problem with my ult frezzer cascade system
with refrigerant r 1270 for high comp and r1150 for low comp with inter cooling spiral 14 m lenght. two comps are using danfoss gs 26 clx.i filled r 1270 at 12 psi r1150 at 12 psi too. but the temperature was stopped at -80 degree. i need it at - 95 degree. any body can help me to solve the problem. thanks at all.

[norseman]

Edi.

At first, the pressures you gives seems to be strange. Is it running pressures you describe?
If this system has a heat exchanger temperature sensor, you can check at what temperature the HX is running. You need some information from the producer about what the HX should be at by the load of the second stage. Such a test would tell you about the harmony between the two stages. Since this one use R1150 in the second stage, oil restriction in the second stage which can be a problem on ultra low system seldom happen. If this unit has servicer valves, a good way to start is to measure the static pressure in the second stage which is normally rated at ambient temperature in the all system. You have several other failures who can ,ake this to happen so if you are common to cascade systems or working on others, you have to track it down by using some common sense:D
The little you tell can not make too many out there to give some advise I think.

[edi]

first thanks for your advised.
full of my cascade system unit below :
2 Gs 26 clx
Refrigerant receiver tank for second stages
oil separator for second stages
hx 14 m lenght
selenoid valve for second stages
automatic pressure switch second stages
filter drier for each stage
thermostat
evaporator about 43 m 3/8 copper pipe tube

first stage running for the hx high compressor with refrigerant r 1270 at 12 psi lp and 240 psi hp (inlet cap tube 2,4 m/m 12 turn) for temperature -31 degree, next second stages running for the hx low compressor with thermostat on -30 degree with refrigerant r 1150 at 12 psi lp and 280 psi hp (outlet cap tube 3,0 m/m 100 turn).
for temperature -95 degree.pressure switch running at second stages hp increasing to 300 psi for sol valve by pass for receiver tank to suction line.oil separator install return back to lp side of the compressor.

next that was stopped at -80 degree the others problem appeared is when shutdown the power mean all the systems, then power on again second stages system pressure become very high and lp dropped to 6 psi. thanks.


best regards,


edi
batam indonesia. :)