Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

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of subfreezing ambient temperatures, then one of the following freeze protection protocols must
be followed:
• An appropriate freeze protection fluid selected for the lowest possible ambient temperatures
must be used in the chilled fluid circuit.
-OR-
• The fluid in the evaporator must be drained as follows:
a. Remove power to the waterbox heaters.
b. Close the chilled fluid circuit isolation valves.
c. Drain the evaporator.
d. Leave the evaporator drain valves open.
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 7: 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
YVAM Control Center 28