Danfoss Optyma OP-UPAC015COP04E, Инструкции по применению

Страница: 33 / 48

5.2 Vacuuming
• After the airtight test, connect the vacuum pump to the low pressure side service port and high pressure side service port, and evacuate.
• Use always a vacuum pump to the equipment. Never attempt to evacuate by its own in any event.
• This unit displays the low pressure digitally on the controller. If the unit is not energized during the evacuation, the controller does not
display the low pressure. Check the low pressure with the gauge manifold or vacuum gauge.
• When the unit is not energized, remove the coil from the medium pressure suction solenoid valve, and open it forcibly using a special
magnet.
• When the unit is energized, turn the DIP switch SW5-7 to ON (Up) to turn on the unit’s power source. The electronic expansion valve and
solenoid valve in the unit open. The vacuum pump is connected to the low pressure side only at that time.
5. System design recommendations
High pressure side service port
Low pressure side service port
Note on R744 (CO
2
) :
Since R744 (CO2) may corrode metals if it solves into water, becoming weakly acidic, it is necessary to dry sufficiently by the
vacuum drying.
Fig. 20
Start evacuation from the low pressure side to prevent the reverse phase on the compressor.
Vacuum sufficiently for 2 to 3 hours after reaching a degree of vacuum at lower than -1 bar.
Use a vacuum pump with a higher exhaust speed. (Conventional small pumps with exhaust
speed of 20 to 30 l/min, which are in use widely, will take too much time.)
Install a vacuum pump adaptor to prevent oil from returning from the pump to the refrigeration
cycle.
Use a manifold valve and a charge hose special to R744 (CO2).
A joint (Reducer) to install on the service valve is included in the accessories. When performing
the airtight test or vacuuming, finish the connection form of the joint according to purposes.
When the degree of vacuum rises, presence of moisture, or leaks, is suspected. Check for
moisture, or leaks. (Special vacuum dry)
i. Vacuum dry (1st).
ii. Vacuum dry (1st). : Pressurize nitrogen gas to 0.5 bar, and charge. Use nitrogen always.
iii. Vacuum dry (2nd).
iv. Ultimate vacuum must be maintained at -1 bar after letting it alone. If it is not, repeat the
vacuum dry and vacuum break.
Reducer
Fig. 21
33
AB408540130380en-000102 © Danfoss | Climate Solutions | 2023.02
Application Guidelines