7. Store the machine.
Precautions against external damage
Avoid storing the machine in a place that is easily accessible or near a construction site. If this is
unavoidable, provide the machine with protection.
If it is not possible to protect the machine, fill the interior with N
2
to minimize the amount of air
leakage. For details, contact your local Johnson Controls service center.
Table 37: Wet storage method
Storage period
Part
Storage method
Notes
Chilled/hot water line
Cooling water line
Filled with water
Storage Period; less than
2 months
Inside of shells
Vacuum
Chilled/hot water
system
Cooling water system
Filled with water
Storage Period; more
than 2 months and less
than 6 months
Inside of shells
Vacuum
Chilled/hot water
system
Cooling water system
Filled with water
Storage Period; more
than 6 months
Inside of shells
Pressurized with nitrogen
(1.5~3PSIG (0.01~0.02 MPa))
1. The manual valve on the purge piping must be fully closed. See Figure 75.
2. If the storage period exceeds 2 months, algae and bacteria can propagate and
corrode the tubes depending on the water quality, chemicals must be fed to
avoid such propagation.
3. If the storage period exceeds 2 months, water inside the chiller-heater must
be replaced. If the same water remains in the chiller-heater for longer than
2 months, bacteria can propagate and corrode the tubes depending on the
environmental condition and water quality. Hence, the chilled/hot water and
cooling water pumps must be operated for a short time periodically and the
water inside chiller-heater must be replaced completely (at least one time
each month).
4. If the storage period exceeds 6 months, apply pressure 1.5~3PSIG (0.01~0.02
MPa) with nitrogen inside the shells and leave as is. Internal-pressure must be
checked at least one time every week to confirm that no pressure drop occurs.
Table 38: Dry storage method
Storage period
Part
Storage method
Notes
Chilled/hot water
system
Cooling water system
Dried and pressurized with
nitrogen (1.5~3PSIG (0.01~0.02
MPa))
Storage Period; less
than 6 months
Inside of shells
Vacuum
Chilled/hot water
system
Cooling water system
Dried and pressurized with
nitrogen (1.5~3PSIG (0.01~0.02
MPa))
Storage Period; more
than 6 months
Inside of shells
Pressurized with nitrogen (1.5 ~
3 psig (0.01 ~ 0.02 MPa))
1. Chilled/hot water and cooling water systems must be drained completely
and dried by nitrogen blow, then pressurized with nitrogen and left as is.
Depending on the water quality, hard scale can be fixed on the inside surface
of tubes by drying and it can be removed by chemical cleaning only. For
more than 1 year’s storage, it is necessary to, after cleaning the tubes, drain
completely, dry up inside by nitrogen blow, then pressurize with nitrogen and
leave as is.
2. If the storage period exceeds 6 months, apply pressure 1.5~3PSIG (0.01~0.02
MPa) with nitrogen inside the shells and leave as is. Internal-pressure must be
checked at least one time every week to confirm no pressure drop occurs.
3. The manual valve on the purge piping must be fully closed. See Figure 75.
Storage method of the cooling water during heating
operation period
Do not operate the cooling water pump during operation in heating mode, simultaneous heating
and residential hot water supply mode, and residential hot water only (sole) supply mode.
Treat the cooling water in the absorber and condenser tubes during the heating operation using
one of the following two methods.
Wet storage
This method of storage leaves water in the tubes. It is applicable to indoor installations.
This condition around the chiller-heater is as follows:
• During the heating operation period, there is no concern about the cooling water freezing. (If
there is a risk of freezing, apply an insulation material to the cooling water piping.
• The cooling tower is installed at the high level (height) of the chiller-heater to prevent the high
temperature water from flowing into the cooling tower.
165
Model YHAU-CGN/H-CXR(M)Double Effect Direct Fired Small Absorption Chiller-Heater
