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RLC-SVX023B-GB
Freeze protection
For all chillers it is extremely important to keep full water fl ow in the evaporator and condenser for an extended time
after last compressor stops. This will protect evaporator tube from freezing by refrigerant migration.
This is why both evaporator and condenser water pump output relay must be used to control the chilled water pump.
It is mandatory even if glycol is used with protection down to lowest ambient expected.
For unit operation in a low temperature environment, adequate protection measures must be taken against freezing.
Freeze protection can be accomplished by adding suffi cient glycol to protect against freezing below the lowest
ambient expected.
Important: Be sure to apply appropriate LERTC (Low Evaporator Refrigerant Temperature Cutout) and LWTC
(Low Water Temperature Cutout) control setpoints based on the concentration of the freeze inhibitor or solution
freeze point temperature.
Avoid the use of very low or near minimum chilled fl uid fl ow rates through the chiller. Higher velocity chilled fl uid
fl ow reduces freeze risk in all situations. Flow rates below published limits have increased freeze potential and have
not been considered by freeze protection algorithms.
• Avoid applications and situations that result in a requirement for rapid cycling or repeated starting and stopping of
the chiller. Keep in mind that chiller control algorithms may prevent a rapid compressor restart after shutting down
when the evaporator has been operating near or below the LERTC limit.
• Maintain refrigerant charge at appropriate levels. If charge is in question, contact Trane service. A reduced or
low level of charge can increase the likelihood of freezing conditions in the evaporator and/or LERTC diagnostic
shutdowns.
Installation - Mechanical
