⚙️ I. Daily Operating Procedures
​​Startup and Shutdown​​
​​Crankcase Preheating​​: After prolonged shutdown, the crankcase heater must be powered on for ​​12–24 hours​​ before restarting to prevent frozen oil from mixing with the liquid refrigerant and causing liquid hammer (damage to valve plates/connecting rods).
​​Test Run​​: Before startup, run the unit idle for 2–3 minutes to check belt tension, pipe seals, and oil level (oil level should be at the midpoint of the sight glass).
​​Valve Operation​​: When starting, open the exhaust valve first, then slowly open the suction valve to avoid sudden overload; after shutdown, immediately disconnect the power supply and drain the condensate.
​​Refrigerant and Oil Management​​
​​Charging Specifications​​:
Refrigerant must be charged from the high-pressure side (the system must be in a vacuum state).
When the refrigerant charge exceeds the limit (e.g., ZR24-ZR47 single-phase > 4.3 kg), a crankcase heater must be installed.
​​Refrigeration Oil Requirements​​:
During initial assembly, 1.5–2 liters of 46# refrigeration oil must be added; otherwise, oil starvation may cause the unit to seize.
Regularly inspect oil quality; replace immediately if cloudy or containing water. Oil change intervals: 24 hours after initial operation → 200 hours → subsequent quarterly/annual maintenance.
​​Safety Precautions​​
​​Prohibited Oxygen Pressure Testing​​: Only nitrogen pressure testing is permitted (with a safety valve).
Prohibited desiccants: Do not use methanol as a desiccant to prevent corrosion of the motor windings.
Handling restrictions: Tilt angle ≤40°, strictly prohibit inverting (to prevent refrigeration oil from flowing into the cylinder).