Johnson Controls York YHAU-CGH-CXR Series, Installation, Commissioning, Operation, And Maintenance

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Changeover to cooling mode
1. Press and hold the Operation Mode Cooling button on the setting screen for 15 seconds. See
Figure 72.
2. Press the Cool or Heat Simultaneous OFF button on the setting screen. See Figure 72.
3. Set each cooling or heating changeover valve to cooling mode. See Table 30.
4. Verify that the cooling water piping system is filled with water.
5. Verify that the tapped air is vented.
6. Open (or close) each valve in the cooling water piping system to ensure the cooling water
circulation in the system.
7. Manually operate the cooling water pump and cooling tower fan.
8. Verify that these can be operated and that the cooling water is circulated.
Note: Do not operate the cooling water pump without operating the chilled/hot water
pump to prevent the freezing of chilled/hot water.
9. While the chiller-heater is stopping, purge the purging tank. See Manual method to purge non-
condensable gas from the purge tank .
10. While the chiller-heater is stopping, purge the absorber. See Manual method to purge non-
condensable gas directly from absorber .
11. Operate the chiller-heater.
12. Purge the absorber again. See Manual method to purge non-condensable gas directly from
absorber .
13. Press the Purge Mode Auto button on the Setting screen. See Automatic method to purge non-
condensable gas from the purge tank .
Changeover to heating mode
1. Select the appropriate method to treat the cooling water in the absorber and condenser tubes
during the heating operation period. See Storage method of the cooling water during heating
operation period .
Note: If the operation mode (cooling or heating) is changed periodically, clean each heat
transfer tube with a nylon brush during this step.
2. Press and hold the Operation Mode Heating button on the Setting screen for 15 seconds. See
Figure 72.
3. Press the Cool or Heat Simultaneous OFF button on the Setting screen. See Figure 72.
4. Set each cooling or heating changeover valve to Heating mode. See Table 30.
5. While the chiller-heater is stopping, purge the purge tank. Use the procedure shown in Manual
method to purge non-condensable gas from the purge tank .
Model YHAU-CGN/H-CXR(M)Double Effect Direct Fired Small Absorption Chiller-Heater 138