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APPENDIX C
Heat/Cool Option
(Available on CN4321 only)
With the Heat/Cool Option, the CN4321 can control a temperature appli-
cation with one input at one main setpoint using two outputs, a heating
output and a cooling output. By using a heating and cooling output, a
process is able to quickly bring the temperature to setpoint in both
directions and to limit the amount of overshoot. The larger the deviation
from setpoint, the more output applied to the system on both the heat-
ing and cooling sides. Heat/Cool control is a very effective way of con-
trolling exothermic processes, processes that generate their own heat,
or processes where ambient temperature is not adequate or fast
enough in returning a process back to setpoint.
The two outputs on the CN4321 are independent and sent to two differ-
ent output devices. The first output could be either a relay or a DC SSR
driver, while the second output has to be a relay output only.
The CN4321 controls the cooling side with three additional parameters,
TC-2, COOL, and DB as explained in the programming section.
TC2
Cycle Time (Output #2):
Because Output #2 is not nec-
essarily the same as Output #1, the cycle time may be
different.
CooL
Proportional Band Coefficient for Cooling:
Because
the cooling power may not necessarily be the same as
the heating power, the cooling proportional band may
be different from that of the heating proportional band.
Summary of Contents for CN4321
Page 33: ...32 SYSTEM WIRING DIAGRAMS Example 1 Example 2...
Page 45: ...44 Deadband Overlap...
Page 48: ...47 Table of Input Type Codes...
Page 50: ...49...
Page 53: ...52 Table of Alarm Action Type Codes CN4321...
Page 54: ...53 Table of Alarm Action Type Codes CN4431...
Page 59: ...58 Table of Output Type Codes...
