The differential pressure controller is also a two-position regulator, also known as a differential pressure relay. Used to control the pressure difference between the oil pump of the compressor, the discharge port and the suction port of the refrigerant liquid pump. This controller is used to control the pressure difference between the outlet of the oil pump and the population, that is, to control the oil supply pressure of the oil pump to ensure the safe operation of the compressor.
The high pressure bellows of the pressure difference controller is connected to the outlet of the oil pump, and the low pressure bellows is connected to the crankcase, and the pressure difference is balanced with the spring force. When the pressure difference value is greater than the given value (usually about 0.15MPa), the position of the angle lever, the circuit bK-DZ is grounded into a path, and the normal working signal light 16 is on; the other circuit bXK-sx-a also becomes a path, and the motor's The AC contactor C is energized, the contacts are closed, and the motor runs normally.
When the pressure difference is less than the given value, the angle lever rotates counterclockwise and is at the position of the dotted line, the circuit bK-DZ of the normal working signal lamp is disconnected from ground, and the normal working signal lamp is off; the circuit bXK-SX-a is still connected, and the compressor continues to run ; And the circuit bKYJ electric heater DXK-sx.
Turn on the heater of the chiller to generate heat and heat the bimetallic strip. After a delay of about 60 seconds, the bimetallic strip bends to the right, causing K: and SI to be connected, the accident light is on, and the circuits of the AC contactor and the electric heater are simultaneously blocked Cut off, the compressor stops, and the electric heater stops heating. After eliminating the fault that the pressure difference is too small, press the manual reset button 10 to energize the coil of the AC contactor C, and the compressor can start.
The function of delaying 60 seconds to operate is to ensure that the compressor can start before the normal oil pressure has been established. As long as the normal oil pressure is established within 60 seconds and the angle lever is in the solid line position, the compressor can be in normal working condition. At the same time, the electric heater circuit is cut off.
