Carrier 50VQP/50BVW SCU Open Controller: Controls, Start-Up, Operation, and Troubleshooting
General Information
This manual details the controls, start-up, operation, and troubleshooting procedures for Carrier's 50VQP and 50BVW self-contained units when equipped with the SCU Open Controller. The SCU Open controller integrates with Carrier's UC Open XP and UC Open XP IO hardware, offering flexible configurations for single-zone space temperature control or multi-zone Variable Air Volume (VAV) applications. It supports operation within the Carrier i-Vu Open network, enabling air and water side linkage, or as a standalone unit.
Safety is paramount. Always follow safety considerations outlined in the manual and adhere to all local building codes and national electrical codes. Wear appropriate safety gear, including safety glasses and work gloves.
Installation and Start-Up
The installation and start-up process involves several key areas:
- Local Access: Local access ports and interfaces like the Field Assistant Application, Equipment Touch Interface, and i-Vu Application are used for system start-up and troubleshooting.
- Input/Output Wiring: Detailed wiring specifications are provided for various inputs (binary, analog) and outputs, including connections for sensors, actuators, and network communication.
- Rnet Wiring: Instructions cover wiring devices to the UC Open XP controller's Rnet port, including ZS sensors, wireless adapters, and the Equipment Touch interface.
- Field-installed Sensors and Accessories: Guidance is provided for installing sensors such as Supply Air Temperature (SAT), Return Air Temperature (RAT), Duct Static Pressure, Relative Humidity, and CO2 sensors.
- Communication Wiring and Addressing: This section details how to address the UC Open XP controller on a BACnet MS/TP network and wiring specifications for BACnet MS/TP and ARC156 communication.
Sequences of Operation
The manual describes the sequences of operation for different configurations:
- CV Sequence of Operation: Applicable to constant volume single-zone applications, covering scheduling, occupancy control, and indoor fan operation (automatic speed control, fan modes, fan delay).
- VAV Sequence of Operation: For multi-zone variable air volume applications, detailing static pressure reset, cooling operation, modulating hot gas reheat, and heating operation.
- Indoor Air Quality (IAQ) and Demand Control Ventilation (DCV): Explains how the system manages indoor air quality using a modulating outdoor air damper based on CO2 levels.
Operation Details
Key operational aspects covered include:
- Indoor Fan Operation: Automatic fan speed control, fan modes (Auto, Continuous, Always On), and fan delay settings.
- Cooling Operation: Details on compressor staging, economizer cooling, and the impact of supply air temperature on fan speed.
- Heating Operation: Information on compressor staging for heating, auxiliary hot water heat, and morning warm-up sequences.
- Setpoints: Configuration and adjustment of occupied and unoccupied cooling and heating setpoints, including demand limiting and hysteresis.
- Learning Adaptive Optimal Start: How the system learns and adjusts start times for optimal comfort and energy savings.
- ZS Sensor Setpoints: Configuration and management of ZS sensors for temperature, humidity, and CO2.
Appendices
The appendices provide supplementary information:
- Appendix A: Wiring Diagrams: Detailed diagrams for the SCU Open Main and SCU Open Extender units.
- Appendix B: BACnet Points List: A comprehensive list of BACnet points, their access levels, default values, and BACnet object IDs.
- Appendix C: Equipment Touch Navigation and Wizard: Guidance on navigating the Equipment Touch interface and using the startup wizard.
