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6.2.3. Case Temperature Control
Case temperature control supports using a
combination of up to six case temperature inputs
as the control input. The CUB-II also supports
multiple strategies for combining multiple case
temp inputs, including minimum temp, maxi-
mum temp, and average temp.
6.3. Defrost Control
The CUB-II controls scheduled defrosts for
its case circuit, and supports both electric and
off-cycle (or timed) defrost. Up to 12 daily
scheduled defrost times can be programmed in
the CUB-II memory. The CUB-II executes
defrost cycles at each scheduled time.
6.3.1. Defrost Termination
The CUB-II allows for defrost termination
based on temperature or suction pressure. Tem-
perature termination can use either a digital
defrost sensor (or Klixon) or an analog termina-
tion sensor, whose value is compared to the ter-
mination setpoint. Suction pressure termination
will terminate a defrost cycle when the suction
pressure rises above a programmed suction pres-
sure termination setpoint.
Defrost cycles may be programmed with a
minimum defrost time and a maximum defrost
time.
6.4. Sensor Control
The CUB-II provides for up to two generic
Cut In/Cut Out control algorithms for use in con-
trolling subsystems related to the condensing
unit. Each sensor control application consists of
an input (or a set of inputs combined into a sin-
gle value), a set of Cut In/Cut Out setpoints, and
a digital output that is controlled by comparing
the input to the setpoints.
Typical uses for a sensor control application
on a CUB-II include: refrigerant leak detection,
motor room temperature control, and case lights.
Defrost Control
6.4.1. How Cut In/Cut Out Control
Works
Cut In/Cut Out setpoints work differently
depending upon whether the Cut In/Cut Out set-
point is higher.
Cut In Higher Than Cut Out
Figure 6-1 - Cut In Setpoint Higher than Cut Out
When the Cut In setpoint is higher than the
Cut Out setpoint, the Sensor Control output turns
ON when the sensor input goes higher than the
Cut In setpoint. The Sensor Control output
remains ON until the input falls below the Cut
Out setpoint, at which time the output turns OFF.
(See Figure 6-1 for an illustration).
MultiFlex CUB-II and CUB-TD Software Overview • 17
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