iWorx® HPU3
2
502-035, Effective: February 21, 2012
© 2012 Taco Electronic Solutions, Inc.
HPU3
The HPU3 heat pump controller is a stand-alone microprocessor-based controller for liquid source heat pump units.
The application includes liquid source heat pump units with two-stage compressor, reversing valve, fan and dehumidifi-
cation.
Overview
The HPU3 incorporates digital outputs in the form of triacs for fan start/stop, two compressor stages, dehumidification
enable, and a reversing valve. An analog output for modulated fan control is also provided. Digital inputs are provided
to monitor equipment status and high and low pressure alarms. A two-wire serial interface is provided for the thermo-
stat. An analog input is available for applications that require power monitoring.
The controller is based on L
ON
W
ORKS
®
networking technology. The controller can be networked to a higher-level control
system for monitoring and control applications.
Features
• Two stage compressor heating/cooling control
• Reversing valve control
• Local backup schedule
• Individual temperature setpoints for occupied/unoccupied heat and cool
• L
ON
W
ORKS
interface to building automation systems
• Equipment status input for additional safety interlocks
• High and Low Pressure Alarm inputs
• Thermostat with space temperature, humidity, temperature setpoint adjust, fan override, occupancy override
• Fan control energized on call for heating or cooling
• Automatic heat/cool changeover
• Global unit enable for main plant synchronization
• Remote sensor capabilities
• Automatic configuration with the LCI
• Real Time Clock
• Alarm/Event reporting
PURPOSE OF THIS GUIDE
The
iWorx® HPU3 Installation Guide
provides installation information for the HPU3 Controller.
The reader should understand basic HVAC concepts, intelligent environmental control automation, and basic L
ON-
W
ORKS
networking and communications. This application manual is written for:
• Users who engineer control logic
• Users who set up hardware configuration
• Users who change hardware or control logic
• Technicians and field engineers
REPRESENTATIONS AND WARRANTIES
This Document is subject to change from time to time at the sole discretion of Taco Electronic Solutions, Inc. All
updates to the Document are available at www.taco-hvac.com. When installing this product, it is the reader’s responsi-
bility to ensure that the latest version of the Document is being used.
