General Information
Oil and Refrigerant Pump
Compressor Lubrication System - A schematic diagram of the compressor lubrication system is illustrated in Figure 16. (This can be applied to circuit 1 or 2.)
Oil is pumped from the oil tank (by a pump and motor located within the tank) through an oil pressure- regulating valve designed to maintain a net oil pressure of 18 to 22 psid. It is then filtered and sent to the oil cooler located in the economizer and on to the bearings. From the bearings, the oil drains back to the manifold under the motor and then on to the oil tank.
WARNING
Surface Temperatures!
MAY EXCEED 150°F. Use caution while working on certain areas of the unit, failure to do so may result in death or personal injury.
To ensure proper lubrication and prevent refrigerant from condensing in the oil tank, a
When the chiller is operating, the temperature of the oil tank is typically 115° to 160°F
Note: A vent line solenoid is not needed with the refrigerant pump. Oil exits the bottom of the manifold and returns to the tank. Separation of the seal leakage gas in the manifold keeps this gas out of the tank.
A dual eductor system is used to reclaim oil from the suction cover and the evaporator, and deposit it back into the oil tank. These eductors use high pressure condenser gas to draw the oil from the suction cover and evaporator to the eductors and then discharged into the oil tank. The evaporator eductor line has a shut off valve mounted by the evaporator and ships closed. Open two turns if necessary.
Liquid refrigerant is used to cool the oil supply to both the thrust bearing and journal bearings. On refrigerant pump units the oil cooler is located inside the economizer and uses refrigerant passing from the condenser to evaporator to cool the oil. Oil leaves the oil cooler and flows to both the thrust and journal bearings.
Motor Cooling System Compressor motors are cooled with liquid refrigerant, see Figure 16.
The refrigerant pump is located on the front of the oil tank (motor inside the oil tank). The refrigerant pump inlet is connected to the well at the bottom of the condenser. The connection is on the side where a weir assures a preferential supply of liquid. Refrigerant is delivered to the motor via the pump. Motor refrigerant drain lines are routed to the condenser.
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