Compressor protection from liquid hazards
AssigneeCarrier Corporation
InventorKevin F. Dudley
Life of this patent
Estimating the term…
Abstract
Two liquid levels are sensed in the oil sump of a compressor to determine if sufficient oil and excess refrigerant are present prior to starting the compressor and appropriate steps taken, if necessary. At start-up, and during operation, the presence or flow of liquid refrigerant in the suction of the compressor is sensed and appropriate steps taken, if necessary.
Claims12
In an air conditioning system under the control of a microprocessor and including a positive displacement compressor having a suction inlet, a motor, an oil sump and a crankcase heater, means for protecting said compressor operatively connected to said microprocessor and including:
- means for sensing the percentage of liquid present at said suction inlet,
- means for preventing the starting of said compressor when said means for sensing the percentage of liquid detects at least a predetermined percentage of liquid;
- means for stopping said compressor when said means for sensing the percentage of liquid detects at least a predetermined percentage of liquid;
- means for activating said crankcase heater at least one time after said means for sensing the percentage of liquid detects at least a predetermined percentage or liquid;
- and
- means for attempting starting said compressor after said crankcase heater has been activated.
In an air conditioning system under the control of a microprocessor and including a positive displacement compressor having a suction inlet, a motor, an oil sump and a crankcase heater, mean for protecting said compressor operatively connected to said microprocessor and including:
- first means for sensing the presence or absence of liquid at a first predetermined level in said sump wherein said first level is indicative of a minimum acceptable oil level in said sump;
- second means for sensing the presence or absence of liquid at a second predetermined level in said sump wherein said second level is above said first level and is indicative of an excess of liquid in said sump;
- means for preventing the starting of said compressor when said first means senses the absence of liquid at said first predetermined level;
- means for preventing the starting of said compressor when said second means senses the presence of liquid at said second predetermined level;
- means for stopping said compressor when said second means senses the presence of liquid at said second predetermine level
- means for activating said crankcase heater at least one time after said second means senses the presence of liquid at said second level;
- and
- means for attempting starting said compressor after said crankcase heater has been activated.
A method for operating an air conditioning system which is under the control of a microprocessor and including a positive displacement compressor having a suction inlet, a motor, an oil sump and a crankcase heater, a method for protecting said compressor including the steps of:
- sensing the percentage of liquid present at said suction inlet;
- preventing the starting of said compressor when liquid in excess of a predetermined percentage is sensed at said suction inlet;
- stopping said compressor when liquid in excess of a predetermined percentage is sensed at said suction inlet;
- activating said crankcase heater at least one time after liquid in excess of a predetermined percentage is sensed at said suction inlet;
- and
- attempting starting said compressor after said crankcase heater has been activated.
Dependencies are inferred from the claim text.