FORM 155.32-ICOM2.EN.UL
SECTION 7 – MAINTENANCE
ISSUE DATE:1/10/2018
JOHNSON CONTROLS
155
Dry Storage
Dry storage involves draining the water from the tubes. It is most often used when the unit
is installed in an outdoor location.
Condition around the chiller-heater:
• During the heating operation period, there is concern of cooling water freezing.
• Cooling tower is installed at the same level (height) of the chiller-heater.
• Lining pipe is used for the cooling water piping system.
Figure 72 -
Dry Storage During Heating Operation Period
Work Procedure
1. Drain all of the cooling water from the absorber and the
condenser
.
2. Flow the clean water from the higher location than the chiller-heater, and then feed
the clean water continuously and clean the tubes well.
3. Fill absorber and condenser with clean water.
4. Circulate it with the cooling water pump for 30 minutes to 1 hour.
5. Drain all of the cooling water from the absorber and the condenser.
6. Dry inside of each water chamber and heat transfer tube well.
7. Keep this condition during heating operation period.
CAUTION: Do NOT leave the tubes in absorber and condenser as is after simply drain-
ing the remained cooling water. If you do, the heat transfer tubes will be at high risk of
corrosion and rusty water (red rust) generation.
LD20942
Start/stop signal for cooling tower fan
Cooling
Tower
Open/close signal for three way valve
Thermometer
Chiller-Heater
Thermometer
Strainer
Close
Cooling water pump
Filled with water
P
T
T
Close
Drain valve
Close
Drain valve
Open slightly
