Sequence of

Controls Operation

• Air-Cooled Condensers

Condenser fans will stage per a user- defined setting. If the condenser is equipped with head pressure control (air modulation on last stage of condenser capacity), the condenser airflow will modulate to maintain condensing temperature setpoint. Condensing temperature is determined by sensors located at each condenser coil.

Water Purge

This user-definable feature allows the user to select a purge schedule to automatically circulate water through the economizer and condensers periodically during non-operational times. This allows fresh chemicals to circulate in waterside heat exchangers.

Airside Options

Inlet GuideVane Control

Inlet guide vanes are driven by a modulating 0-10 vdc signal from the RTM module. A pressure transducer measures duct static pressure, and the inlet guide vanes modulate to maintain the supply air static pressure within an adjustable user-defined range. The range is determined by the supply air pressure setpoint and supply air pressure deadband, which are set through the human interface panel.

Inlet guide vane assemblies installed on the supply fan inlet regulate fan capacity and limit horsepower at lower system air requirements. When in any position other than full open, the vanes pre-spin the air in the same direction as supply fan rotation. As the vanes approach the full- closed position, the amount of “spin” induced by the vanes increases at the same time that intake airflow and fan horsepower diminish. The inlet guide vanes will close when the supply fan is off.

Variable Frequency Drive (VFD) Control Variable frequency drives are driven by a modulating 0-10 vdc signal from the RTM module. A pressure transducer measures duct static pressure, and the VFD adjusts the fan speed to maintain the supply air static pressure within an adjustable user-defined range. The range is determined by the supply air pressure setpoint and supply air pressure deadband, which are set through the human interface panel.

Variable frequency drives provide supply fan motor speed modulation. The drives will accelerate or decelerate as required to maintain the supply static pressure setpoint.

Bypass control is offered as an option to provide full nominal airflow in the event of drive failure. Manual bypass is initiated at the human interface panel. When in the bypass mode,VAV boxes will need to be fully opened. The self-contained unit will control heating and cooling functions to maintain setpoint from a user defined zone sensor. Supply air static pressure limit will be active in this mode.

Supply Air Static Pressure Limit

The opening of the inlet guide vanes and VAV boxes are coordinated during unit start up and transition to/from occupied/ unoccupied modes to prevent overpressurization of the supply air ductwork. However, if for any reason the supply air pressure exceeds the user- defined supply air static pressure limit that was set at the human interface panel, the supply fan/VFD is shut down and the inlet guide vanes close. Then unit will attempt to restart, up to three times. If the overpresssurization condition still occurs on the third restart, the unit shuts down and a manual reset diagnostic sets and displays at the human interface panel.

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Trane PKG-PRC002-EN manual Airside Options, Air-Cooled Condensers, Water Purge, Inlet GuideVane Control
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PKG-PRC002-EN specifications

The Trane PKG-PRC002-EN is a groundbreaking packaged rooftop unit designed to meet the diverse needs of commercial and industrial spaces. This model showcases Trane’s commitment to innovation, energy efficiency, and reliability, making it a preferred choice for HVAC professionals and building owners alike.

One of the main features of the PKG-PRC002-EN is its high-efficiency design. This unit leverages advanced technologies to minimize energy consumption while ensuring optimal cooling and heating performance. Its efficient compressor, coupled with enhanced heat exchangers, significantly reduces operating costs and energy bills, aligning with today’s sustainability goals.

The PKG-PRC002-EN features a robust and durable construction, which translates to enhanced longevity and reduced maintenance requirements. Designed for ease of installation, the unit is compact and lightweight, facilitating seamless retrofitting and integration into existing systems. Furthermore, its accessible service panels allow for straightforward maintenance and repairs, thus minimizing downtime and service disruptions.

Equipped with Trane's advanced control technology, the PKG-PRC002-EN offers precise temperature management, ensuring consistent comfort across different zones within a building. The intuitive controls enable users to program schedules and adjust settings based on their specific needs, enhancing comfort while maximizing efficiency.

The model also incorporates advanced filtration options, improving indoor air quality by effectively reducing pollutants and allergens. This focus on health and safety is essential, especially in commercial settings where air quality can significantly impact occupant well-being and productivity.

Another notable characteristic of the PKG-PRC002-EN is its low noise levels during operation, which is essential for maintaining a conducive indoor environment in workplaces, retail spaces, or educational institutions. The unit's design minimizes sound transmission, creating a more pleasant atmosphere for occupants.

In summary, the Trane PKG-PRC002-EN is a highly efficient, reliable, and user-friendly rooftop unit that combines advanced technology with robust construction. Its energy-saving features, superior air quality options, and focus on quiet performance make it an excellent choice for modern commercial HVAC applications, ultimately contributing to sustainable building practices and enhanced occupant comfort.
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