Step 1: Maintenance items after 300‑500 hours of operation for new units Change oil and oil filter; clean the air filter element; inspect for leakage and loose connections; drain the oil‑gas separator tank; check belt tension of moving components. Check motor temperature rise, electric current and air‑end operating noise.

Step 2: Maintenance items after 2000 hours of operation for new units Inspect for leakage and loose connections; drain the oil‑gas separator tank; clean the unit body; check pressure differential; clean the radiator; manually test the safety valve (pull‑rod test); inspect belt tension and transmission assembly. Check motor temperature rise, electric current and air‑end operating noise.

Step 3: Maintenance items after 6 months or 4000 hours of operation (whichever comes first) Change oil and oil filter; clean or replace the air filter element; replace the oil‑gas separator element (or when pressure differential exceeds 0.08 MPa). Inspect for leakage and loose connections; drain the oil‑gas separator tank; clean moving components; check oil‑gas separation pressure differential; clean the radiator; manually test the safety valve (pull‑rod test); replenish lubricating grease for bearings of motor and cooling fan; inspect electrical insulation and contact conditions; check safety‑protection devices; inspect aging of circulating system; inspect belt tension and transmission assembly. Check motor temperature rise, electric current and air‑end operating noise.

Step 4: Maintenance items after 12 months or 8000 hours of operation (whichever comes first) Change oil and oil filter; clean or replace the air filter element; replace the oil‑gas separator element (or when pressure differential exceeds 0.08 MPa). Inspect for leakage and loose connections; drain the oil‑gas separator tank; clean moving components; check oil‑gas separation pressure differential; clean the radiator; replenish lubricating grease for bearings of motor and cooling fan. Inspect electrical insulation and contact conditions; check safety‑protection devices; inspect aging of circulating system and control system. Send the safety valve and pressure gauge to state‑authorized institutions for calibration.