York YHAU-CE, Installation Operation & Maintenance, Page: 89 / 136

JOHNSON CONTROLS
89
SECTION 7 – MAINTENANCE
FORM 155.35-ICOM2.EN.CE/GB (1018)
DATE: 10/30/2018
7
PURGE PROCEDURE
Non-condensable gas must be purged from the chiller-
heater to maintain its performance and prevent dete-
rioration of its internal parts. This chiller-heater has an
automatic purge system.
Even if the automatic purge mode is used during nor-
mal operation, perform the manual operation for the
purging tank and absorber periodically. For the purging
period, see
Table 20 on page 95 .
Manual Method to Purge Non-condensable
Gas Directly from Absorber
When the chiller-heater operates at a lower capacity
than usual for a long period of time or when it restarts
after a power failure, the absorber may contain non-
condensable gases. If the machine starts under these
conditions, its performance and efficiency go down. If
this happens, purge air directly from the absorber man-
ually according to the following procedure.
1. Set the valves according to pattern B shown in
Table 19 on page 90 .
2. Navigate to the Control Panel Setting screen.
3. Press the Purge Mode
Manual button.
4. Press the Manual Purge ON button. The vacuum
pump starts and the solenoid valves SV1 and SV2
open.
5. After 1-2 minutes, confirm that the vacuum gauge
stands at 0~1 kPa.
6. Reading the vacuum gauge, open valve V17 grad-
ually. Confirm that the pressure on the vacuum
gauge increases slightly.
If the pressure decreases when valve V17
opens, the vacuum pump capacity is too
small. Close valve V17 at once. Check the
purge line.
7. If no problems are found, open valve V17.
Make sure the valve is completely open.
8. Continue the purge for up to 3 hours.
9. Close valve V17.
10. Press the Manual Purge OFF button. The vacuum
pump stops and the solenoid valves close.
Manual Method to Purge Non-condensable
Gas from Purging Tank
While the absorption chiller-heater operates, non-
condensable gas collects in the purging tank. You can
purge those gases manually using the following pro-
cedure.
1. Set the valves according to pattern C shown in
Table 19 on page 90
.
2. Navigate to the Control Panel Setting screen.
3. Press the Purge Mode
Manual
button.
4. Press the Manual Purge ON button. The vacuum
pump starts and the solenoid valves SV1 and SV2
open.
5. 3-4 minutes after the vacuum pump starts, con-
firm that the vacuum gauge stands at 0~1 kPa.
6. Reading the vacuum gauge, gradually open valve
V19.
7. The manual purge procedure is complete when
the pressure reaches 3 kPa on the vacuum gauge.
8. Close valve V19.
9. Press the Manual Purge
OFF button. The vacuum
pump stops and the solenoid valves close.