Fig. 4 Ð Lubrication System

journal bearings within the bearing housing. The oil then drains into the oil reservoir at the base of the compressor. The PIC (Product Integrated Control) measures the temperature of the oil in the sump and maintains the temperature during shut- down (see Oil Sump Temperature Control section, page 32). This temperature is read on the LID default screen.

During the chiller start-up, the PIC will energize the oil pump and provide 15 seconds of prelubrication to the bear- ings after pressure is veri®ed before starting the compressor. During shutdown, the oil pump will run for 60 seconds to post-lubricate after the compressor shuts down. The oil pump can also be energized for testing purposes in the Control Test.

Ramp loading can slow the rate of guide vane opening to minimize oil foaming at start-up. If the guide vanes open quickly, the sudden drop in suction pressure can cause any refrigerant in the oil to ¯ash. The resulting oil foam cannot be pumped efficiently; therefore, oil pressure falls off and lubrication is poor. If oil pressure falls below 15 psid (103 kPad) differential, the PIC will shut down the compressor.

Oil Reclaim System Ð The oil reclaim system oper- ates to return oil back to the oil reservoir by recovering it from 2 areas on the chiller. The primary area of recovery is from the guide vane housing. Oil also is recovered, along with refrigerant, from the cooler.

Any refrigerant that enters the oil reservoir/transmission area is ¯ashed into gas. The demister line at the top of the

casing will vent this refrigerant into the suction of the com- pressor. Oil entrained in the refrigerant is eliminated by the demister ®lter.

DURING NORMAL CHILLER OPERATION, oil is entrained with the refrigerant. As the compressor pulls the refrigerant into the guide vane housing to be com- pressed, the oil will normally drop out at this point and fall to the bottom of the housing where it accumulates. Us- ing discharge gas pressure to power an eductor, the oil is vacuumed from the housing by the eductor and is dis- charged into the oil reservoir. Oil and refrigerant are also recovered from the top of the cooler refrigerant level and are discharged into the guide vane housing. The oil will drop to the bottom of the guide vane housing and be recovered by the eductor system.

DURING LIGHT LOAD CONDITIONS, the suction gas into the compressor does not have enough velocity to return oil, which is ¯oating in the cooler back to the compressor. In addition, the eductor may not have enough power to pull the oil from the guide vane housing back into the oil reservoir due to extremely low pressure at the guide vanes. Two so- lenoids, located on the oil reclaim piping, are operated so that the eductor can pull oil and refrigerant directly from the cooler and discharge the mixture into the oil reservoir. The oil reclaim solenoids are operated by an auxiliary contact integral to the guide vane actuator. This switchover of the solenoids occurs when the guide vanes are opened beyond 30 degrees from the closed position.

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Carrier 19XL specifications Lubrication System
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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.
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