LX Series Heat Pump Unit Controller User's Guide10
Sensor Configuration Wizard
The Heat Pump Unit Controller incorporates the Johnson Controls® sensor
configuration wizard. The wizard provides powerful and simple configuration
tools for the hardware inputs. You can only select digital or analog inputs through
the software. You do not need to move any circuit board jumpers.
Analog input signal types–resistive, voltage, current–are selected in software
without hardware jumpers. Built-in conversion tables are provided for a large
number of thermistors or other sensor types. You can easily create custom
conversion tables by setting the offset, minimum, and maximum values in one
dialog box for the input.
The sensor configuration wizard also provides direct access to network properties
of the analog or digital input including the Standard Network Variable Type
(SNVT), Heartbeat, Send on Delta, Override, Default Value, and Throttle settings.
All of the input features are in one place; therefore, it is not necessary to switch
back and forth between screens to fully configure an input.
The sensor configuration wizard provides warnings of configuration errors as they
occur, allowing you to correct mistakes quickly.
The sensor configuration wizard is accessible in the LX-HPUL wizard view of an
LX-HPUL device in FX Workbench. Each hardware input is represented by a
separate LONMARK object. To configure each input, select the desired hardware
input on the left side of the LX-HPUL wizard view and Sensor Configuration in
the Wizard column of the view and click the Launch button. The sensor
configuration wizard opens. Through use of the wizard, you can configure network
inputs not directly controlled by the HPU Controller.
Control Features
The Heat Pump Unit Controller provides Proportional plus Integral plus Derivative
(PID) loops for advanced control of humidity, discharge temperature, and space
temperature. Each PID loop has an individual, configurable dead band; and,
provides gain and time adjustment for the integral and derivative terms, and gain
adjustment for the proportional term.
Humidification and dehumidification sequences provide the Heat Pump Unit
Controller with the ability to maintain space humidity at the desired level. Defrost
cycles are started by the HPU when the differential pressure is high, or by a
sequence in conjunction with the refrigerant temperature sensor. Space
temperature control is done with a PI loop only, but the presence of the derivative
term provides the HPU Controller with the ability to precisely adjust space
temperature. Precision adjustment ensures both increased comfort and savings.
Often associated with air handlers, the HPU Controller provides advanced control
settings including Optimum Start and load shedding.