SECTION 7 – MAINTENANCE
FORM 155.32-ICOM2.EN.UL
ISSUE DATE:1/10/2018
128
JOHNSON CONTROLS
MANUAL METHOD TO PURGE NON-CONDENSABLE GAS FROM THE
PURGE TANK
While the absorption chiller-heater operates, non-condensable gas collects in the purging
tank. You can purge those gases manually using the following procedure.
1. Set the valves according to Pattern C, see
.
2. Press the Purge Mode
Manual
button.
3. Press the Manual Purge
ON
button. The vacuum pump starts. The solenoid valves
SV1 and SV2 open.
4. After 1-2 minutes, confirm that the vacuum gauge indicates approximately1 kPa.
5. Verify that valve V10 is open.
6. Reading the vacuum gauge, gradually open valve V11.
7. The manual purge procedure is complete when the pressure reaches 3 kPa and be-
low on the vacuum gauge.
8. Close valve V11.
9. Press the Purge Pump
OFF
button. The vacuum pump stops. For information on how
to set up an automatic purge,
Automatic Method to Purge Non-condensable Gas
from the Purge Tank on page 128
.
AUTOMATIC METHOD TO PURGE NON-CONDENSABLE GAS FROM
THE PURGE TANK
This chiller-heater has an automatic purge system. The vacuum pump starts and stops by
detecting the pressure inside the purge tank.
1. Set the valve according to Pattern D.
Purge Valve Operation on page 133
.
2. Press the Manual Purge
OFF
button.
3. Press the Purge Mode
Auto
button.
4. The purge solenoid valves automatically open and close.
During the automatic purge operation, the vacuum pump starts when the purging tank
pressure increases to 7 kPa abs and stops when it decreases to 3 kPa abs.
WARNING: When you replace the oil in the vacuum pump or belt or perform
maintenance work while the absorption chiller-heater is running, be sure to turn off the
circuit breaker of the vacuum pump in the control panel. If not, the vacuum pump could
start abruptly and cause injury.
