In applications where a freeze protection fluid is not used but continuous power to the chiller
control panel, chilled fluid circuit pumps, and evaporator heaters can be guaranteed during periods
of subfreezing ambient temperatures, then one of the freeze damage protection protocols in the
following table must be followed.
Table 12: YVAM freeze damage protection requirements
Condition
Chiller control of chilled fluid
circuit pumps
Waterbox immersion heaters
Ambient air temperatures from 32°F (0°C) down to
0°F (-17.8°C)
Required
Not required
Ambient air temperatures below 0°F (-17.8°C) down
to -20°F (-28°C)
Required
Required
Evaporator water piping
Level and wedge the unit in place for optional spring isolators before you install the piping
connections for the chilled water. The piping must be arranged with offsets for flexibility, and
adequately supported and braced independently of the chiller to avoid pipe strain on the chiller
and for isolation of vibration transmission. Note the following considerations for the installation of
evaporator water piping:
• Hangers must allow for alignment of pipe. Isolators, in the piping are a preferred option,
and may be required by specifications in order to effectively use the vibration isolation
characteristics of the vibration isolation mounts of the unit. Johnson Controls do not supply the
isolators.
• Piping connecting to chillers on spring isolators must be isolated with correctly aligned and
supported flexible connections. Otherwise, the piping joint becomes the primary resistance to
motion, and pipe or fittings are likely to deform or fatigue during operation.
• Piping and fittings immediately next to the evaporator must be readily removable to enable
cleaning before operation and to facilitate visual inspection of the exchanger nozzles.
• The evaporator liquid heads of the chiller have nozzles that are grooved, but are also suitable
for welding 150 psig DWP flanges or the use of flexible couplings. Factory mounted flanges
are optional. If the nozzles are welded, disconnect the flow switches and water temperature
thermistors. Make sure that the welding ground has good electrical contact located directly on
the piping or waterbox to prevent welding voltage or current damage to the devices.
• The nozzles and water pass arrangements are furnished in accordance with the job
requirements. Refer to the product drawings furnished with the job. Standard units are
designed for 150 psig DWP on the water side. If the job requirements are for greater than 150
psig DWP, check the unit data plate before applying pressure to evaporator water circuit to
determine if the chiller has provisions for the required DWP.
• Foreign objects that could lodge in, or block flow through, the evaporator tubes must be kept
out of the water circuit. Clean and flush all water piping before connecting the piping to the
chiller pumps or other equipment.
• The evaporator must not be exposed to flushing velocities or debris released during flushing.
Install a suitably sized bypass and valve arrangement to facilitate flushing of the piping system.
The bypass can be used during maintenance to isolate the heat exchanger without disrupting
flow to other units.
Note:
The evaporator must be protected by a strainer, preferably of 16 mesh, fitted
as close as possible to the liquid inlet connection, and provided with a means of local
isolation.
• Provide thermometer and pressure gauge connections on the inlet and outlet connections of
each evaporator. Johnson Controls do not supply or furnish the gauges or the thermometers.
35
YVAM Air-Cooled Centrifugal Liquid Chiller
