6200 series Operations Manual
Rev D 2/14/2012
Page 25 of 60
Operation of the Defrost / Low Temperature System
A Defrost System is used to maintain operational temperature below 5ºC. When the
chamber temperature is below 4.5ºC, the defrost system is enabled automatically.
When the chamber temperature is above 4.5ºC (except during a defrost cycle), the
defrost system is disabled automatically.
When the defrost system is enabled (below 4.5ºC), a defrost cycle will occur once
every 96 hours and lasts for 20 minutes. During the defrost cycle, the chamber
temperature will increase several degrees above set point to melt any ice that has
formed on the evaporator. This temperature ‘spike’ is normal and assures long-term
operation.
Operation in Low Temperature Mode (6220 & 6240 only)
When the chamber is operating at temperatures below 4.5C, it automatically enters the
Low Temperature Mode. In this mode, the humidity control and display is disabled
because of the risk of water freezing and causing damage. When in low temperature
mode, the humidity controller will not turn on and the yellow ‘inactive’ light will
illuminate when the humidity switch is turned on.
