JOHNSON CONTROLS
94
FORM 155.35-ICOM2.EN.CE/GB (1018)
DATE: 10/30/2018
SECTION 7 – MAINTENANCE
DECRYSTALLIZATION METHOD
Even if the solution in the absorption chiller-heater is
crystallized during operation, it can be melted if the
crystallization is not severe. Crystallization becomes
increasing difficult to melt as time passes. As soon as
you observe crystallization, immediately perform the
following operation. If the crystals does not melt us-
ing the following procedure, notify your local Johnson
Controls Service Center immediately.
Indications of Crystallization
• The refrigerating capacity goes down, the liquid
level in the absorber drops, and cavitation noise
comes out of the solution pump.
• The
Solution Circulation P Abnormal
or the
Solution Spray Pump Abnormal
buttons on the
Failure screen light and the solution pump trips.
• The liquid level in the absorber is low. The solu-
tion level seen through the high temperature gen-
erator level gauge (LG3) is white.
• The liquid level in the absorber drops and the tem-
perature of the solution returning from the high
temperature generator goes down.
Decrystallization
1. Stop the absorption chiller-heater. If the solution
pump tripped, reset the thermal relay.
2. Disconnect the electrical wiring of the solution
pump.
3. Navigate to the Setting screen on the Control Pan-
el.
4. Press the Forced Dilution
ON
button.
Since the electrical wiring of the solution
pump is disconnected, only the refrigerant
pump starts.
5. Remove the cap of the refrigerant manual blow-
down valve V2.
For the location of the refrigerant manual
blow valve, see Table 18 - Solenoid Valves
6. Turn the spindle in the valve to the left with the
8 mm hexagon wrench.
The refrigerant in the refrigerant tank
diverts into the absorber.
7. Watch the liquid level of the refrigerant tank.
8. Immediately after the refrigerant liquid level ap-
pears in the level gauge of the refrigerant tank,
close the refrigerant manual blow-down valve
(turn it to the right until it stops).
9. Press the Refrigerant Pump
STOP
button. The re-
frigerant pump stops.
10. Press the Forced Dilution
OFF
button.
11. Re-connect the electrical wiring of the solution
pump.
12. Press the Forced Dilution
ON
button. The solu-
tion pump starts.
13. Navigate to the Main screen on the Control Panel.
14. Set the temperature controller (TIC) to manual
mode for the waste exhaust gas.
15. Adjust both to 30-40%.
16. Watch the liquid level in the absorber while you
perform the adjustments.
17. When the liquid level in the absorber drops, set
the temperature controllers to 0% for the waste
exhaust gas.
18. Navigate to the Control Panel Setting screen.
19. Press the Forced Dilution
OFF
button.
20. Repeat steps 12 - 19 four times.
21. If the liquid level in the absorber does not drop,
the crystals have melted.
22. Press the Forced Dilution
ON
button. The solu-
tion pump operates independently. Let it run for
30 minutes.
23. Watch the liquid level in the absorber while the
solution pump runs.
24. After 30 minutes press the Forced Dilution
OFF
button.