York YHAU-CGN, Installation Operation & Maintenance

Page: 117 / 182

FORM 155.32-ICOM2.EN.UL SECTION 6 – OPERATION
ISSUE DATE:1/10/2018
JOHNSON CONTROLS 117
Use Simultaneous Residential Hot Water Supply Mode (Option) for Chillers
with Evaporator Heating
In this mode, residential hot water is supplied through the auxiliary heat exchanger (option)
while chilled water or hot water is supplied through the evaporator.
1. Check that the correct Operation Mode button ( Cooling or Heating ) is pressed on the
Setting screen. See Figure 55 on page 112
2. Press the Simultaneous ON button on the Setting screen. See Figure 55 on page 112
3. Press the RHW only operation OFF button on the Setting screen.
4. Set each Cooling or Heating changeover valve and manual valve to the desired opera-
tion mode (“Simultaneous cooling and residential hot water supply” mode or “Simulta-
neous heating and residential hot water supply” mode). See
Table 33 on page 119
Changeover to Residential Hot Water Sole Supply Mode (Option) for Chillers
with Evaporator Heating
In this mode, residential hot water is supplied through the auxiliary heat exchanger (option),
No chilled/hot water is supplied through the evaporator.
1. Choose how to treat the cooling water in the absorber and condenser tubes during the
residential hot water supply operation period. See Storage Method of the Cooling Wa-
ter During Heating Operation Period on page 153 , for more information and instruc-
tions.
2. Choose how to treat the chilled/hot water in the evaporator tubes during the residen-
tial hot water supply operation period. See Storage Method of the Cooling Water
During Heating Operation Period on page 153 , for more information and instructions.
3. Verify the following two manual valves are open:
a. on the weak solution line from the low-temperature heat exchanger to the solution
flow control float valve in the high-temperature generator.
b. on the strong solution line from the high-temperature heat exchanger to the solu-
tion spray pump.
4. Press and hold the Forced Dilution ON button on the Setting screen for 10 seconds.
See Figure 55 on page 112
5. The solution pump and refrigerant pump start independently.
6. Open the refrigerant manual blow valve. For the location of the blow valve. See Fig-
ure 59 on page 124 . The refrigerant in the evaporator is diverted into the absorber.
7. Observe the liquid level at the lower part of the evaporator through the level gauge
(G102).
8. Immediately after the refrigerant liquid level appears in the level gauge (G102), close
the refrigerant manual blow valve (turn it to the right until it stops).
9. Press the Refrigerant Pump Stop button on the Setting screen. See Figure 55 on
page 112 .
10. The refrigerant pump stops. Run the solution pump independently for 10 minutes.
11. Press the Forced Dilution OFF button on the Setting screen. See Figure 55 on page
112 . The solution pump stops.
CAUTION: If you need to change the operation mode, remember to press and hold the
button for 15 seconds.
CAUTION: The chilled/hot water pump should be operating during forced dilution to
prevent freezing of the chilled/hot water.