(20–60Ton

Controls Interface)

Head Pressure Control — Condenser head pressure control is provided in the UCM by staging condenser fans on or off to maintain the saturated condensing temperature. This function will allow cooling operation down to 30°F as standard. Minimum on and off timing is built into the algorithm to prevent rapid cycling.

Pump down — This feature can be enabled or disabled through the Human Interface. When it is enabled, pump down will be initiated prior to shutting down the last capacity stage on each circuit by de-energizing a liquid line solenoid valve. Pump down is terminated by the opening of the low pressure switch, or 30 seconds after the cycle is initiated. On units equipped with hot gas bypass, pump down will be initiated upon termination of the hot gas bypass cycle.

Chiller Solution Pump Control — The UCM has two operating modes for the chiller solution pump control, Auto and On. The UCM additionally has a relay output that will energize/de-energize the chiller’s solution pump control circuit. The relay is de-energized, stopping the pump, when emergency stop is activated. The solution pump relay is energized to run the pump in the following modes: freeze protection, normal cooling control, low ambient freeze protection, ice building and loop stabilization, and service mode. Modes that will request the pump to stop are ice building complete, ice building delay, unit stop and external auto/stop.

Low Ambient Start Control — Two functions are integrated into the control to allow operation in extreme conditions and still protect the overall system. Low ambient start control will allow compressor operation below 65°F. In order to avoid nuisance tripping, the low

pressure control will be bypassed for a period of time. If the low pressure control is still open at the end of the period, the compressor is shut down and the solenoid valve is opened. The loss of refrigerant flow protection is active in this sequence to additionally protect the chiller.

Hot Start Control — A high ambient start sequence will permit only one compressor to operate when the leaving solution temperature is in the user adjustable range of 60-80°F. When the leaving solution temperature falls below this high limit, the second compressor will be active.

Low Ambient Compressor Lockout — This function will lock out the compressor if the outdoor air temperature is below the low ambient compressor lock out temperature set point. This set point is adjustable at the Human Interface Panel (HI) between 0- 60°F. Compressors will be locked out when outdoor air temperatures fall below that selected temperature and will be allowed to start again when the temperature rises 5° F above the set point.

Compressor Lead/Lag — Compressor lead/lag is a user-selectable feature through the Human Interface Panel available on all units.When enabled, the algorithm in the UCM will start compressors based upon the least number of starts and/or run time. This feature is not available with the hot gas bypass option.

Emergency Stop Input — A binary input is provided on the Unit Control Module (UCM) for installation of field provided switch or contacts for immediate shutdown of all unit functions.

External Auto/Stop — A set of contacts or switches can be field installed that will start and stop the chiller.

Demand Limit — The UCM will accept an input from a field installed device which will prevent one or more compressors from operating. The user can select the number of compressors to be turned off.

Leaving Solution Reset — This flexible option allows active leaving solution reset based on customer selectable inputs from the zone, entering solution temperature or outside air temperature. When the application is sensitive to one of these parameters, subcooling of critical zones is prevented.

Optional Control Features

Compressor Current Sensing — This option will measure and average the amp draw of 2 phases of each compressor.

Superheat/Subcooling Option — This option will include the necessary temperature and pressure sensors to measure and calculate the chiller’s superheat and subcooling numbers for each circuit. These temperatures and pressures, along with calculated values of superheat/subcool, will be displayed in the status menu of the Human Interface. No external refrigerant gauges need to be installed on the chiller for the system operator to check out these conditions.

External Leaving Solution Set point — Remote set point potentiometer can be ordered to allow adjustment of the leaving solution set point remotely.

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Trane CG-PRC007-EN manual Optional Control Features
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CG-PRC007-EN specifications

The Trane CG-PRC007-EN is a robust product within the Trane line of commercial rooftop units, designed to meet the heating and cooling needs of various commercial applications. This unit showcases advanced technologies and features aimed to enhance efficiency, reliability, and user comfort.

One of the standout characteristics of the CG-PRC007-EN is its commitment to energy efficiency. The unit incorporates high-efficiency compressors and a variable-speed fan motor, ensuring that the system can adjust its operation based on the demand, thus optimizing energy consumption. This is particularly advantageous in commercial settings, where climate control requirements can fluctuate throughout the day.

Additionally, the unit is engineered with a smart control system that allows for easy integration with building management systems. This feature enables real-time monitoring and adjustments, helping facility managers maintain optimal comfort levels while also minimizing operational costs. Users are able to access performance data and system diagnostics remotely, promoting proactive maintenance and reducing downtime.

Durability and longevity are critical factors for commercial HVAC systems, and the CG-PRC007-EN is designed with this in mind. The unit features a corrosion-resistant cabinet and components that withstand harsh weather conditions, ensuring reliability in outdoor installations. Its robust construction helps mitigate noise levels, resulting in a quieter operation that is ideal for noise-sensitive environments.

Another key technology within this unit is its advanced airflow management system. This system is designed to provide consistent airflow, enhancing indoor air quality and ensuring that every corner of the space benefits from appropriate heating or cooling. The CG-PRC007-EN also offers a variety of customization options for air filters, ensuring that the specific needs of each application are met.

Furthermore, the unit is compliant with the latest environmental regulations, including those set forth by the EPA. It utilizes eco-friendly refrigerants that minimize environmental impact without sacrificing performance. This makes the CG-PRC007-EN an excellent choice for companies committed to sustainability and energy efficiency.

In summary, the Trane CG-PRC007-EN combines innovative technology, energy efficiency, and reliability, making it an ideal solution for commercial heating and cooling needs. Its advanced features, durability, and eco-friendly design position it as a leader in the commercial rooftop unit market.
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