Replacement Of Filter Dryer; Service And Maintenance; Evacuation Of Refrigerant - Maersk Container Industry Star Cool SCI-20 Operating And Service Manual

82 of 116 pages

21.8 Replacement of filter dryer

Before replacing the drying filter, the power plug to the unit has to be disconnected.
The drying filter has to be changed every time the compressor is changed or if the moisture
indicators indicate too much moisture in the refrigerant circuit. To change the drying filter, please
follow the procedure below:
1. Power off the unit.
2. Close the stop valve, pos. 14 (P & I diagram).
3. Start the unit in Manual operation.
4. Select compressor frequency to 40 Hz.
5. Observe the suction pressure (Psuc). When Psuc = 0 BarE, power off the unit.
6. Carefully loosen the two union nuts for the drying filter. Beware of pressurized escaping
refrigerant. Always wear protective goggles and gloves.
7. Replace the drying filter with a Danfoss DML 164 O-ring or equivalent. Before mounting of the
filter, put some drops of compressor ester oil on the flare in order to ensure correct tightness.
8. Tighten the two union nuts for the drying filter. (see "26.12 Tightening torques" p. 110).
9. Remove the electrical coils and mount permanent magnet on the two electronically expansion
valves, pos. 16 and 18 (P & I diagram).
10. Carefully loosen the upper union nut for the drying filter, allowing a little amount of refrigerant
gas to escape.
11. Tighten the union nut.
12. Remove the permanent magnets and reinstall the electrical coils on the two electronically
expansion valves, pos. 16 and 18 (P & I diagram).
13. Open the stop-valve, pos. 14 (P & I
14. Power up the unit.

22. Service and maintenance

22.1 Evacuation of refrigerant

Evacuation of refrigerant from the unit is done by the following procedure:
1. Connect a service gauge manifold to the evacuation point, pos. 6 and 27 (P & I diagram) on the
compressor.
2. Connect a recovery unit to the gauge manifold.
a. Connect a recycling bottle to the recovery unit.
b. Use a scale underneath the bottle, for measuring the amount of recycled refrigerant.
3. If it is NOT possible to run the compressor:
a. Remove the electrical coils and install a permanent magnet on the 3 valves pos. 16, 18, and
32 (P & I diagram).
b. Turn off the unit.
c. Close and open again, the discharge service valve pos. 5 (P & I diagram) approx. 4 turns.
d. Check that the recovery unit is set for vapour recovery.
e. Open both service gauge manifold valves (LP/HP). Continue to 5.
4. If possible to run the compressor:
a. Continue operation of the compressor.
b. Close the economizer service valve, pos. 14 (P & I diagram), and run a pump down of the
LP side of the compressor to approx. -0.8 BarE.
c. Turn off the compressor.
d. Close the suction service valve, pos. 26 (P & I diagram). Before operating the suction
service valve, loosen the gland seal by ¼ turn before you move the spindle. Once finished,
tighten the gland seal and put on the protective spindle cap.
e. Check the recovery unit is set for vapour recovery.
f. Remove the electrical coils and install a permanent magnet on the 2 valves, pos. 16 and 18
(P & I diagram).
g. Open only the HP valve on the service gauge manifold.
5. Start and operate the recovery unit as long as necessary to evacuate the desired amount of
refrigerant from the unit, until no pressure left.
diagram).