Application

Considerations Self-Contained

Recommended Pump Location

Locate pump downstream of the cooling tower and upstream of the self-contained unit. This provides smoother and more stable unit operation.

When the tower and pump are both roof mounted, be sure to provide the necessary net positive suction head pressure to prevent cavitation. Raise the tower or submerge the pump in a sump to provide positive suction.To prevent an on-line pump failure, use a standby pump to avoid a complete system shutdown. Several partial capacity pumps or variable speed pumps may be used. Review the economics of these alternate pumping options.

Strainers and Water Treatment Water strainers are required at the unit inlet to eliminate potential unit damage from dirty water. Specify a water basket- type strainer to avoid an incorrect stream strainer application. Untreated or poorly treated water may result in equipment damage. Consult a water treatment specialist for treatment recommendations.

Isolation Valves

Install isolation valves at each unit before the strainer and after the condenser.This allows periodic servicing of the unit or

strainer while allowing other units in the system to remain in operation.

Pressure Gauges

Install pressure gauges on the inlet and outlet of the self-contained unit. Select the gauge’s scale so that the unit design operating point is approximately mid- scale.

Thermometers

Install thermometers on the condenser water inlet and outlet lines to each unit for system analysis.Trane Company recommends using a thermometer temperature range of 40 to 140 F, using a 2 F temperature increment.

Drains

The unit condensate drain is internally trapped to offset the pressure differential that exists during fan operation. Install a trapped drain in the low point of the mechanical equipment room floor to collect water from cleaning operations.

Condensing Pressure Control (Water-Cooled condensers)

Often cold condensing water applications between 35 F (1.7 C) and 54 F (12.2 C) require a condensing pressure control valve. Any unit with variable-flow waterside valves can modulate water flow to maintain a user defined condensing temperature. However, to

utilize this feature, the building water system must be capable of operating at reduced water flow rates through the self-contained units. It is imperative to install variable volume pumps or an external bypass in the water distribution system.

Waterside Economizer Flow Control Units equipped with waterside economizer control valves can be set up for variable or constant water flow.

Use constant water flow setup on water systems that are not capable of unloading water supply to the unit. The economizer and condenser valves will operate in complement to one another to provide continuous water flow.

Use variable water flow setup with water flow systems that can take advantage of pump unloading for energy savings.

Since non-cooling operation restricts water flow during part load economizing or condensing temperature control, it is imperative to install variable volume pumps or an external bypass in the water distribution system.

Unit Operating Limits

Airflow

The minimum recommended airflow for proper VAV system staging and temperature control is 35 percent of nominal design airflow. AdjustingVAV boxes with the appropriate minimum settings will prevent the self-contained unit from operating in a surge condition at airflows below this point. Continuous operation in a surge condition can cause fan failure. Reference General Data Tables on pages 17-20 for minimum airflow conditions.

Signature Series self-contained units use fixed pitch sheaves. Adjust air balancing by obtaining alternate fixed pitch sheave selections from the localTrane sales office.

Waterflow

Use 3 gpm/ton for optimum unit capacity and efficiency. Use 2.5 or 2 gpm/ton to reduce pump energy, cooling tower and piping costs. However, these reduced waterflows may impact unit capacity and efficiency by one or two percent. Consult General DataTables on pages 17-20 for unit specific waterflow ranges.

Waterside Economizer Piping

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PKG-PRC002-EN

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Trane PKG-PRC002-EN manual Unit Operating Limits
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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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