JOHNSON CONTROLS
144
FORM 155.30-ICOM2.EN.UL
ISSUE DATE: 12/21/2018
SECTION 7 – MAINTENANCE
FLOW SPEED IN TUBES
Since the water flow speed in the tubes is closely relat-
ed to any existing corrosion, do not increase the water
supply rate more than recommended. If the flow speed
reaches 11.6 to 13.3 feet per second, the tubes may
erode. When changing the flow rate, contact your local
Johnson Controls Service Center.
If the water supply rate is adjusted at the inlet side of
the heat exchanger (evaporator, condenser, absorber,
and generator), the eddy current at the inlet may cor-
rode the tube.
Be sure to control the flow rate on the outlet side.
The eddy current caused by foreign matter in the heat
exchanger is also a factor in corrosion. Be sure to in-
stall a strainer on the inlet side of the heat exchanger
and clean the strainer every 3 months..
STORAGE METHOD OF THE CHILLER
If the chiller needs to be stored longer than 15 days, the
storage method varies. This depends on the machine
room temperature condition and the storage period. If
the machine room temperature is below 32°F, drain off
the chilled water, cooling water, and the hot water. Dry
the tube interiors. Make sure all equipment installed in
the chilled water, cooling water, and hot water lines is
completely dry.
Nitrogen gas pressurization inside the absorption
chiller is required when the storage period exceeds 6
months. Contact your local Johnson Controls Service
Center for more details.
DANGER: The chiller is not explosion
proof. Highly flammable items, gas, or
liquids should not be handled or stored
near the chiller and must be removed.
Failure to do this may result in explosion,
injury, or damage to the equipment and/
or building.
There are two storage methods available for the chiller
during off-season (winter) or plant suspension; the wet
storage method and the dry storage method. The wet
storage method is available only where the chilled wa-
ter, cooling water and/or the hot water will not freeze.
Each storage method has its own characteristics. Select
the method to use based on the plant’s features and the
storage period. Details follow.
Wet Storage Method
The wet storage method may be used when there is no
concern about chilled water, cooling water, and/or the
hot water freezing in winter. Store the machine in a
place where the ambient temperature will remain high-
er than 32°F.
If it is likely that the temperature will drop below that,
provide a heater for the machine. If a heater is not pos-
sible, contact your local Johnson Controls service cen-
ter for further information. For details on the wet stor-
age method, see
.
The wet storage procedure is as follows if the chilled
water, cooling water and/or the hot water line is an
open system:
1. Completely drain the water from the systems if it
has deteriorated in quality.
2. Clean the water systems by passing clear water
through them from a position higher than the
chiller.
3. Fill the water systems with clear water.
4. Circulate the clear water through the water pump
for 30 minutes to one hour to clean it.
5. Drain the water.
6. Completely fill the water systems with clear water
again.
7. Store the machine.
