©2025 Copeland LP.
026-1803 R13 Supervisor I&O User Guide 9 - 62
9.43.3.5 Case States
The XM Circuit application provides a circuit status output
(CASE STATE OUT) to indicate the mode of operation of the
circuit.
The XM Circuit application supports the following case states:
The XM Circuit application determines the state of each
associated case controller by evaluating CASE REFR STA and
CASE DEFR STA. Based on the value of these two input
properties, one of the three case states listed in Table 9-25 is
selected and written to the corresponding CASE STATE OU
output property.
9.43.3.6 Case Type
The Case Type parameter permits the user to select the type
of refrigerated case that will be used for the XM Circuit
application. Based on this setting, the case temperature
setpoint and certain defrost parameters will be set to suitable
values.
9.43.4 Application Advisory
The following advisories are generated by the XM Circuit
application:
• Combined Case Temperature High/Low
• Product Temperature High/Low
• Defrost did not start
9.43.4.1 Synchronized Alarm Parameters
The XM Circuit application will synchronize the Case Alarm
High and Low setpoints with associated XM devices. The
circuit will not perform the alarming functionality for Case
Temperature as it is handled in each XM device.
Because XM devices support relative and absolute alarming
for Case Temperature, the XM Circuit will support the Case
Alarm Hi and Case Alarm Lo parameters as either
temperature or temperature Engineering Units.
9.43.5 Application Commands
The following application commands will be supported by
the XM Circuit application:
9.43.5.1 Start Defrost
When the user selects this command, a defrost cycle is
immediately initiated. The START DEFR OUT output will turn
ON and will stay ON for the duration specified in the Min Defr
Time parameter. If at anytime during this period the user
issues a Stop Defrost command, the START DEFR OUT
output will immediately turn OFF.
9.43.5.2 Stop Defrost
When the user selects this command, a defrost cycle is
immediately stopped. The STOP DEFR OUT output will turn
ON and will stay ON for a period of one minute, and then will
switch OFF. If at anytime during this period the user issues a
Start Defrost command, the STOP DEFR OUT output will
immediately turn OFF.
9.43.5.3 Case Clean Out
Case Clean Out can be enabled from the Cleaning Switch
parameter in the Genera tab of the XM Circuit application. Set
the mode form the Cleaning Mode parameter and configure
Failsafe time settings.
9.43.6 Product Probe Support
The XM Circuit application supports a product probe
temperature input for each case controller associated. To
enable support for product temperature inputs, set the “En
Product Prob” parameter to Yes.
If one or more product probe inputs are used, high and low
temperature alarming may be enabled.
9.44 XR75CX Case Display
The XR75CX-Case Display is a microprocessor based
controller, suitable for applications on medium or low
temperature ventilated refrigeration units. It has up to four (4)
analog inputs: discharge air temperature, product
temperature, defrost temperature and coil out temperature,
four (4) relay outputs, and up to two (2) digital inputs.
Table 9-25 - Case States
State Description
Off
The circuit is shut down. All associated case
controllers are neither refrigerating nor
defrosting.
Refrigeration
The circuit is refrigerating. Most associated
case controllers are in the refrigeration state
(maintaining case temperature setpoint).
Defrost
The circuit is in defrost. Most associated case
controllers are in a defrost cycle. (The defrost
cycle includes several sub-states, for example,
pump down, drip, and more.)
NOTE
NOTE: The behavior of the START DEFR OUT
output is the same whether it is started by the
Start Defrost command or by a regularly
scheduled defrost.
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