Screen 6: Defrost - Emerson MultiFlex CUB-II Installation And Operation Manual

Offset
The Offset field allows you to calibrate a
sensor by adjusting the raw sensor value by a
fixed amount. The value entered in the Offset
field will always be added to the raw sensor
value in the engineering units designated for that
sensor.
An offset can also be used to subtract from a
raw sensor value. To do this, enter a negative
value in the Offset field.

7.3.6. Screen 6: Defrost

Figure 7-8 - Screen 6: Defrost Screen
Defrost Type
Choose the manner in which the case circuit
will be defrosted in the Defrost Type field.
There are two options:
• Off Cycle - Refrigeration will be disabled during de-
frost, and no heat will be directly applied to the
evaporator.
• Electric - Refrigeration will be disabled during de-
frost, and electric heat will be applied to the evapo-
rator.
Defr Pump Down
Enabling Defrost Pump Down causes the
CUB to delay transition from Refrigeration to
Defrost to allow refrigerant to be pumped out of
the evaporator.
To enable the Pump Down Delay, set this
field to ENABLE. To disable the Pump Down
Delay, set this field to DISABLE.
34 • MultiFlex CUB-II and CUB-TD I&O Guide
Term. Type
The Termination Type determines which
sensor's value will be used to determine when a
defrost cycle must be terminated. There are six
options:
• Digital - Digital temperature sensor (Klixon).
• Term Temp - Analog temperature sensor. Defrost
will terminate when the temperature is above the ter-
mination temp setpoint.
• Time - Defrost will terminate when defrost time ex-
pires (this is the same as no termination).
• Min Case Temp - Instead of using a dedicated
"Term Temp" sensor, the CUB will use the lowest
value among all case temperature sensors as the de-
frost termination temperature value.
• Suction Pressure - The suction pressure transducer.
Defrost will terminate when suction pressure rises
above the termination pressure setpoint.
• Case Temp 1-6 - Instead of using a dedicated "Term
Temp" sensor, the CUB will use one of the six case
temperature sensors as the termination sensor during
defrost.
Suction Term
If you selected Suction Pressure as the Ter-
mination Type, the Suction Term field will
appear on this screen. Enter the suction pressure
that, when exceeded by the suction transducer,
will cause defrost to terminate.
Fans dur def
Fans During Defrost determines the state of
the case circuit evaporator fans when defrost is
active for the circuit. Set this field to ON to turn
the case fans ON during defrost, or OFF to turn
the case fans OFF.
Fans at idle
This field determines the state of the case
circuit evaporator fans when the case tempera-
ture setpoint is satisfied and refrigeration is not
active in the case. Set this field to ON to leave
the case fans ON during idle, or OFF to turn the
case fans OFF.
026-1705 Rev 7 06-APR-2010