Fig. 3 Ð Refrigerant Motor Cooling and Oil Cooling Cycles

Refrigerant that ¯ows to the oil cooling system is reg- ulated by a thermostatic expansion valve. There is always a minimum ¯ow bypassing the TXV, which ¯ows through an ori®ce. The TXV valve regulates ¯ow into the oil/ refrigerant plate and frame-type heat exchanger. The bulb for the expansion valve controls oil temperature to the bear- ings. The refrigerant leaving the heat exchanger then returns to the cooler.

LUBRICATION CYCLE

Summary Ð The oil pump, oil ®lter, and oil cooler make up a package located partially in the transmission casting of the compressor-motor assembly. The oil is pumped into a ®lter assembly to remove foreign particles, and is then forced into an oil cooler heat exchanger where the oil is cooled to proper operational temperatures. After the oil cooler, part of the ¯ow is directed to the gears and the high speed shaft bearings; the remaining ¯ow is directed to the motor shaft bearings. Oil drains into the transmission oil sump to com- plete the cycle (Fig. 4).

Details Ð Oil is charged into the lubrication system through a hand valve. Two sight glasses in the oil reservoir permit oil level observation. Normal oil level is between the middle of the upper sight glass and the top of the lower sight glass

when the compressor is shut down. The oil level should be visible in at least one of the 2 sight glasses during operation. Oil sump temperature is displayed on the LID default screen. Oil sump temperature ranges during compressor operation between 100 to 120 F (37 to 49 C) [120 to 140 F (49 to 60 C)].

The oil pump suction is fed from the oil reservoir. An oil pressure relief valve maintains 18 to 25 psid (124 to 172 kPad) differential pressure in the system at the pump discharge. This differential pressure can be read directly from the Local Interface Device (LID) default screen. The oil pump discharges oil to the oil ®lter assembly. This ®lter can be valved closed to permit removal of the ®lter without drain- ing the entire oil system (see Maintenance sections, pages 61 to 65, for details). The oil is then piped to the oil cooler. This heat exchanger uses refrigerant from the condenser as the coolant. The refrigerant cools the oil to a temperature between 100 and 120 F (37 to 49 C).

As the oil leaves the oil cooler, it passes the oil pressure transducer and the thermal bulb for the refrigerant expan- sion valve on the oil cooler. The oil is then divided, with a portion ¯owing to the thrust bearing, forward pinion bear- ing, and gear spray. The balance then lubricates the motor shaft bearings and the rear pinion bearing. The oil temper- ature is measured as the oil leaves the thrust and forward

8

Page 7 Page 9
Page 8
Image 8
Carrier 19XL specifications Lubrication Cycle, Refrigerant Motor Cooling and Oil Cooling Cycles
Page 7 Page 9

19XL specifications

The Carrier 19XL is a highly regarded commercial heating and cooling solution, designed to provide optimum performance and energy efficiency in various applications. This rooftop unit is engineered to meet the diverse needs of businesses, making it an ideal choice for those requiring reliable climate control in their facilities.

One of the standout features of the Carrier 19XL is its advanced cooling and heating capabilities. The unit utilizes a high-efficiency scroll compressor that ensures a quieter operation and improved reliability. The system can operate across a wide range of temperatures, making it versatile for various climates. Additionally, it offers both cooling and heating options, allowing for year-round comfort.

Energy efficiency is a focal point of the 19XL design. With an impressive Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF), this unit not only helps reduce energy costs but also supports environmental sustainability initiatives. The unit is equipped with environmentally friendly refrigerants, further contributing to lower greenhouse gas emissions.

The Carrier 19XL features a user-friendly control system, allowing for easy monitoring and management of the unit's performance. This control system is designed to maximize energy savings, offering features such as demand control ventilation and integrated economizers that facilitate the use of outdoor air for cooling, reducing reliance on mechanical systems when conditions allow.

Construction-wise, the Carrier 19XL is built to withstand tough environmental conditions. Its robust cabinet is made from galvanized steel, providing durability and protection against the elements. The design also includes insulation to minimize noise levels, creating a more comfortable indoor environment.

Maintenance is a key consideration in the design of the 19XL. The unit features accessible service ports and a simplified access panel, allowing technicians to perform routine maintenance with ease. This proactive design helps ensure the longevity of the system and minimizes downtime, keeping operations running smoothly.

In summary, the Carrier 19XL is an exceptional choice for commercial heating and cooling needs. With its energy-efficient features, advanced technology, and durable construction, it stands out as a reliable solution for businesses looking for sustainable climate control options.
Top Page Image Contents