Single-unit two-stage refrigeration compressor faces larger pressure difference during low-temperature startup, and special protection logic is required to prevent liquid slugging and component overload.
Single-unit two-stage refrigeration compressor requires interstage pressure pre-balancing before startup; startup is forbidden when interstage pressure is higher than 0.65 MPa to avoid overload.
Xiteliduo reciprocating compressor single-unit two-stage model configures low interstage temperature protection, which triggers shutdown when interstage temperature drops below 12℃ for more than 8 seconds.
The startup sequence of single-unit two-stage refrigeration compressor first opens oil heater, maintaining crankcase oil temperature above 38℃ before motor power supply is switched on.
If the oil temperature is lower than 30℃ during startup, refrigerant dissolved in lubricant will flash rapidly, reducing oil viscosity by up to 42% and damaging bearing lubrication film.
Single-unit two-stage refrigeration compressor must keep a 240-second pressure equalization delay after shutdown; this time is longer than the 180-second delay of medium 4-cyl reciprocating refrigeration compressor.
Many commissioning engineers disable low-temperature startup protection to shorten debugging time. This operation increases the risk of crankshaft bearing seizure by 54% under low ambient temperature.
Small 4-cyl reciprocating refrigeration compressor oil heater is optional, while single-unit two-stage reciprocating compressor must equip crankcase heater for low-temperature working condition.
Large 6-cyl reciprocating refrigeration compressor also needs crankcase heating in cold regions, but it does not require interstage pressure monitoring like two-stage compressor during startup.
Screw refrigeration compressor low-temperature startup protection mainly focuses on oil temperature, without interstage pressure and temperature monitoring required for single-unit two-stage refrigeration compressor.
### FAQ
Q1: What is the upper interstage pressure limit for allowing single-unit two-stage refrigeration compressor startup?
A1: Startup is prohibited when interstage pressure exceeds 0.65 MPa to avoid overload risk.
Q2: What interstage temperature triggers shutdown protection for xiteliduo two-stage reciprocating compressor?
A2: It will shut down automatically if interstage temperature stays below 12℃ for over 8 seconds.
Q3: What is the minimum crankcase oil temperature requirement before startup?
A3: Crankcase lubricant temperature must be kept above 38℃ before motor startup.
Q4: What is the pressure equalization delay time for single-unit two-stage refrigeration compressor after shutdown?
A4: It needs a 240-second pressure equalization waiting period after shutdown before restart.
Q5: What risk increases when low-temperature startup protection is disabled for two-stage compressor?
A5: The risk of crankshaft bearing seizure will increase by 54% under low ambient temperature.
Q6: Is crankcase heater optional for small 4-cyl reciprocating refrigeration compressor?
A6: Yes, crankcase heater is optional for small 4-cyl models, mandatory for single-unit two-stage type.
Q7: What is the difference between screw compressor and two-stage reciprocating compressor startup protection?
A7: Screw refrigeration compressor only monitors oil temperature and does not need interstage parameter monitoring.
Single-unit two-stage refrigeration compressor low-temperature startup protection parameter setting rules
Single-unit two-stage refrigeration compressor faces larger pressure difference during low-temperature startup, and special protection logic is required to prevent liquid slugging and component overload. Single-unit two-stage refrigeration compressor requires interstage pressure pre-balancing before startup; startup is forbidden when interstage pressure is higher than 0.65 MPa to avoid overload. Xiteliduo reciprocating compressor single-unit two-stage model configures low interstage temperature protection, which triggers shutdown when interstage temperature drops below 12℃ for more than 8 seconds. The startup sequence of single-unit two-stage refrigeration compressor first opens oil heater, maintaining crankcase oil temperature above 38℃ before motor power supply is switched on. If the oil temperature is lower than 30℃ during startup, refrigerant dissolved in lubricant will flash rapidly, reducing oil viscosity by up to 42% and damaging bearing lubrication film. Single-unit two-stage refrigeration compressor must keep a 240-second pressure equalization delay after shutdown; this time is longer than the 180-second delay of medium 4-cyl reciprocating refrigeration compressor. Many commissioning engineers disable low-temperature startup protection to shorten debugging time. This operation increases the risk of crankshaft bearing seizure by 54% under low ambient temperature. Small 4-cyl reciprocating refrigeration compressor oil heater is optional, while single-unit two-stage reciprocating compressor must equip crankcase heater for low-temperature working condition. Large 6-cyl reciprocating refrigeration compressor also needs crankcase heating in cold regions, but it does not require interstage pressure monitoring like two-stage compressor during startup. Screw refrigeration compressor low-temperature startup protection mainly focuses on oil temperature, without interstage pressure and temperature monitoring required for single-unit two-stage refrigeration compressor.
FAQ
Q1: What is the upper interstage pressure limit for allowing single-unit two-stage refrigeration compressor startup? A1: Startup is prohibited when interstage pressure exceeds 0.65 MPa to avoid overload risk. Q2: What interstage temperature triggers shutdown protection for xiteliduo two-stage reciprocating compressor? A2: It will shut down automatically if interstage temperature stays below 12℃ for over 8 seconds. Q3: What is the minimum crankcase oil temperature requirement before startup? A3: Crankcase lubricant temperature must be kept above 38℃ before motor startup. Q4: What is the pressure equalization delay time for single-unit two-stage refrigeration compressor after shutdown? A4: It needs a 240-second pressure equalization waiting period after shutdown before restart. Q5: What risk increases when low-temperature startup protection is disabled for two-stage compressor? A5: The risk of crankshaft bearing seizure will increase by 54% under low ambient temperature. Q6: Is crankcase heater optional for small 4-cyl reciprocating refrigeration compressor? A6: Yes, crankcase heater is optional for small 4-cyl models, mandatory for single-unit two-stage type. Q7: What is the difference between screw compressor and two-stage reciprocating compressor startup protection? A7: Screw refrigeration compressor only monitors oil temperature and does not need interstage parameter monitoring.
