SP Scientific Freezemobile Series, Operator'S Manual, Page: 24 / 54

Sentry 2.0 Controls VirTis Freezemobile 25L and 35L
14 Rev 005, 02/12
© SP Scientific 2012
Factory Options
The Factory Options screen is used to configure the Bath, Purge, Defrost and Heat
options.

Factory Options
Bath Option YES
Purge Option YES
Hot Gas Defrost YES
Heat Option No
ZL Defrost No
Factory Options are enabled when set to YES, and disabled when set to NO.
Bath, Purge and Heat Options
Enabling these options results in changes to the Main Menu and Synoptic screens,
adding control of these features.
Hot Gas Defrost
The Hot Gas Defrost option uses a hot gas refrigeration loop to reduce defrost time.
ZL Defrost
For every eight hours of runtime, the ZL Defrost function activates two minutes of hot
gas bypass to prevent oil buildup in refrigeration lines.
Note: ZL Defrost functions on ZL systems only.
Interstage Control
If your unit is equipped with a cascade refrigeration system, you can control the
operation of the second compressor from the Interstage Control screen. A cascade
system is a safety feature used to protect the refrigeration system from overloading.

Interstage Control
Interstage ON
ON –12 DIFF 025
Current Temp 1.3

C
If the Interstage Control is set to ON, the COND or AUTO buttons will activate the
high-stage compressor. The Interstage Control’s Current Temp is monitored until the
Interstage ON temperature is reached. Once the Interstage ON temperature is
reached, the low-stage compressor is activated.
The DIFF temperature is used to prevent overloading of the high-stage compressor. If
the Current Temp exceeds the sum of the Interstage ON temperature and the DIFF
value, the low-stage compressor is deactivated. It will reactivate when the Current
Temp recovers.