Controls

(10, 15 Ton)

 

 

 

 

SEQUENCE OF UNIT OPERATION

Refer to the unit wiring schematic pasted to the inside of the control panel cover when reviewing the control sequence described below.

Refer to the legend on the previous page for an explanation of the abbreviations used in this sequence.

10-Ton Operation

With fused disconnect switch closed, power is supplied to the crankcase heaters and the 24-volt control circuit.

Starting the chilled water pump closes the CWPS auxiliary contacts and completes the flow switch.

When the water temperature rises above theWTT’s set point, its first stage switch closes, allowing power to pass through CWPS auxiliary contacts, the flow switch, the LTC, the ASCT1, the RR1 contacts, the LPC01, and the HPC01 to energize the CC1 coil.This starts compressor number one and the outdoor fan.

If compressor number one can’t satisfy the cooling demand,WTT’s 2nd stage switch closes, allowing power to pass through the CC1 auxiliary contacts, the DBC, the ASCT2, the RR2 contacts, the LPC02, and the HPC02 to energize the CC2 coil which starts compressor number two.

15-Ton Operation

With fused disconnect switch closed, power is supplied to the crankcase heaters, and the 24-volt control circuit.

Starting the chilled water pump closes the CWPS auxiliary contacts and completes the flow switch, allowing power to pass through the LTC to energize the CWFIR.

When the water temperature rises above theWTT’s set point, its first stage switch closes, allowing power to pass through the CWFIR contacts, the ASCT1, the RR1 contacts, the LPC01, and the HPC01 to energize the CC1 coil.This starts compressor number one and outdoor fan number one.

If compressor number one can’t satisfy the cooling demand,WTT’s second stage switch closes, allowing power to pass through the CWFIR contacts, the DBC, the ASCT2, the RR2 contacts, the LPC02, and the HPC02 to energize the CC2 coil. This starts compressor number two and outdoor fan number two.

LOW AMBIENT OPERATION

Field Installed Head Pressure Control Accessory

Standard units will operate in outdoor ambient temperatures down to the values shown in the “General Data” section of this catalog. This accessory will enable units to operate down to much lower temperature extremes (see “General Data” section of this catalog).

Head pressure control for CGA units is regulated by means of a field-installed head pressure accessory which varies condenser fan speed in relation to discharge pressure.

When discharge pressure is 270 psig or higher, the condenser fan runs at full speed. At pressures between 270 psig and 180 psig, the fan speed is adjusted (increased or decreased) in direct relation to the pressure, with minimum fan speed (10 percent of rated motor rpm) occurring when the pressure reaches 180 psig. At pressures below 180 psig, the fan will not run.When discharge pressure rises to 180 psig, the fan will start and run at the reduced speed. Fan speed will continue to increase, as the pressure increases, until full speed is reached at 270 psig.

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CG-PRC007-EN

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Trane CG-PRC007-EN manual 10, 15 Ton, Ton Operation, Field Installed Head Pressure Control Accessory
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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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