Monthly Maintenance
Perform monthly maintenance after every 200–250 hours of operation. Estimated time: 1–2 hours.
Hydraulic System
| Task | Details |
|---|---|
| Oil sample lab analysis | Send a sample to a qualified oil analysis lab. Test for viscosity, water content, acid number (TAN), particle count (ISO 4406). |
| Return filter element | Replace (first replacement at 500h, then every 2000h or per OEM recommendation). |
| Tank breather / air filter | Inspect and replace if clogged. |
| Relief valve test | Briefly test system relief pressure against specification. |
| Accumulator pre-charge | Check nitrogen pre-charge pressure. Recharge if > 10% below specified value. |
Electrical System
| Task | Details |
|---|---|
| Torque check main power terminals | Use torque wrench. Check main breaker, servo drive input, heater contactor terminals. |
| Thermal imaging | Scan electrical cabinet with an IR camera. Hot spots indicate loose connections or failing components. |
| Ground resistance test | Verify ground resistance ≤ 4Ω. |
| Servo drive cooling fan | Check fan operation. Clean fan grille. |
| Battery backup voltage | Check controller and drive backup battery voltage. Replace if < 3.0V (for 3.6V lithium cell). |
Mechanical System
| Task | Details |
|---|---|
| Tie bar elongation measurement | Measure tie bar stretch with a dial caliper or ultrasonic tension meter. All four bars should be within 5% of each other. |
| Injection unit guide rails | Clean and re-lubricate guide rails. Check for flat spots or brinelling. |
| Nozzle alignment | Check nozzle center alignment with sprue bushing. Misalignment causes mold damage. |
| Clamp mechanism (toggle) | Inspect toggle pins and bushings for wear. Grease all toggle lubrication points. |
| Screw pull-back inspection | Pull the screw, inspect flights for wear, chrome flaking, or material adhesion. |
Cooling System
| Task | Details |
|---|---|
| Heat exchanger cleaning | Chemically clean or back-flush water-side of shell-and-tube cooler. |
| Cooling water analysis | Test water for hardness, pH, conductivity, bacteria. |
| Chiller / tower (if owned) | Inspect chiller refrigerant level, compressor oil. |
⚠️
Oil analysis is the single most valuable predictive maintenance tool for hydraulic machines. A monthly oil sample costs far less than a pump replacement. Set up a regular schedule with a qualified lab.