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Set UCM addresses, connect Comm4 wiring, and 24Vac power for VariTrac UCMs.
Install zone sensors and setpoints to VariTrac damper UCMs at addresses #1 and #2.
Locate, verify address, and connect wiring/power for the communicating sensor/bypass damper assembly.
Prepare the VariTrac Central Control Panel by removing modules and connecting power and communication.
Apply power, view initialization, and configure system settings via the operator display.
The VariTrac system is a comprehensive HVAC control solution designed for commercial office environments, specifically demonstrated in this manual for an installation at B&R Specialty Metals. It is engineered to manage the climate of multiple zones within a building, ensuring optimal comfort and energy efficiency. The core components of the VariTrac system include the VariTrac Central Control Panel (CCP), VariTrac Unitary Control Modules (UCMs), digital zone sensors, and a communicating bypass damper assembly.
The VariTrac CCP serves as the central brain of the system, orchestrating the operation of all connected devices. It provides a user-friendly interface for system setup, monitoring, and adjustment. Through the CCP, users can configure various parameters, including system name, HVAC unit type, and discharge heating setpoints. It also offers a detailed view of the status of each controlled zone and the overall HVAC system. The CCP is designed to be intuitive, allowing for easy navigation through menus to access advanced settings, view alarms, schedule operations, and perform after-hours adjustments. Its display module provides real-time feedback, such as current temperature readings for each zone and system initialization status. A key feature of the CCP is its ability to undergo a calibration mode after initial startup. During this process, the system automatically prepares for operation by disabling heating and cooling, closing the bypass damper, opening all zone dampers to their maximum position, and starting the fan. This calibration re-indexes zones, adjusts the bypass damper, and recalibrates the static pressure setpoint, ensuring the system operates efficiently from the outset.
VariTrac UCMs are distributed controllers that manage individual zones or specific components within the HVAC system. In the context of zone control, each UCM is paired with a digital zone sensor, which provides temperature and setpoint feedback. These UCMs are responsible for controlling the dampers that regulate airflow to their respective zones, ensuring that each area maintains its desired temperature. The UCMs communicate with the CCP via a Comm4 link, allowing for centralized control and monitoring. Each UCM board has address DIP switches that must be set to unique addresses for proper communication within the system. This addressing scheme ensures that the CCP can identify and interact with each UCM individually. Power to the UCMs is supplied via 24Vac connections, and it is crucial to observe polarity, especially if multiple controllers share a common transformer, to prevent operational issues.
The digital zone sensors are integral to maintaining comfort within each controlled zone. These sensors not only measure the ambient temperature but also allow occupants to adjust the setpoint for their specific area. Some sensors may also include an adjustable setpoint feature, providing local control over comfort levels. The sensors communicate with their respective UCMs, which then make decisions about damper positions to achieve the desired temperature. The installation of these sensors involves connecting them to the UCMs using provided wiring harnesses, ensuring proper connections for both sensor data and adjustable setpoint signals.
The communicating bypass damper assembly is a critical component for managing supply air static pressure and temperature. This assembly typically includes a sensor/bypass control unit and a damper actuator. It is strategically located between the supply fan and the bypass damper, ideally in a location with minimal air turbulence, to accurately monitor and control the air distribution. The sensor/bypass control unit communicates with the CCP, providing data on static pressure and temperature, which the system uses to adjust the bypass damper. This helps maintain consistent airflow and pressure within the ductwork, preventing issues like excessive noise or insufficient air delivery to zones. The bypass damper assembly also features address DIP switches, which must be set to a specific address (e.g., '33') for proper integration into the Comm4 link. Similar to UCMs, it requires 24Vac power, and careful attention to polarity is necessary during installation.
For maintenance, the VariTrac system is designed with accessibility in mind. The CCP's display and main modules can be removed from the termination module, providing access to the termination board wiring for inspection or troubleshooting. The system's diagnostic capabilities, including the display of fault conditions and initialization status, aid in identifying and resolving operational issues. The calibration mode, performed after initial setup, also serves as a diagnostic and optimization routine, ensuring all components are synchronized and functioning correctly. The modular design of the system, with separate components like UCMs and sensors, allows for easier replacement or repair of individual parts without affecting the entire system.
The VariTrac system also integrates with other building management systems, such as the Tracker 10, which can control additional HVAC components like rooftop units, exhaust fans, and outdoor lighting, as well as manage occupancy for the VariTrac system itself. This integration enhances overall building automation and energy management. The system's reliance on a robust Comm4 communications link ensures reliable data exchange between all connected devices, forming a cohesive and intelligent control network. Proper wiring and adherence to installation guidelines, including observing polarity for power and communication links, are paramount for the system's stable and efficient operation. The comprehensive installation and operator manuals provide detailed instructions and troubleshooting tips, empowering technicians to install, configure, and maintain the VariTrac system effectively.
General| Category | Temperature Controller |
|---|---|
| Manufacturer | Trane |
| Input Voltage | 24 VAC |
| Enclosure Rating | NEMA 1 |
| Communication Protocol | BACnet |
| Humidity Range | non-condensing |
