Maintenance
Scroll compressors have significantly lower maintenance requirements than piston or screw, but require attention to specific components.
Maintenance Program
Daily Checks
| Task | What to Check |
|---|---|
| Indicators | Pressure, temperature, status |
| Noise | Changes in level or tone |
| Vibrations | Abnormal |
| Condensate | Drain traps |
| Leaks | Visual at connections |
Periodic Maintenance
| Interval | Action |
|---|---|
| 500-1,000 h | Change inlet filter |
| 2,000-4,000 h | Oil change (lubricated) |
| 4,000-8,000 h | Change oil filter |
| 4,000-8,000 h | Inspect/replace tip seals (oil-free) |
| 8,000-16,000 h | Scroll inspection |
| 16,000-24,000 h | Bearing verification |
| 40,000-60,000 h | Major overhaul |
Wear Components
Inlet Filter
Ambient air
│
▼
┌─────────────┐
│ ░░░░░░░░░░░ │ ← Filter
│ ░░░░░░░░░░░ │ (retains particles)
└──────┬──────┘
│
▼
Clean air
to compressor
| Condition | Action |
|---|---|
| Differential 1-2" H₂O | Normal |
| Differential 3-4" H₂O | Consider change |
| Differential 5+" H₂O | Immediate change |
Oil (Lubricated Only)
| Check | Frequency |
|---|---|
| Level | Daily |
| Color | Weekly |
| Analysis | Annual |
| Change | 2,000-4,000 h |
Recommended oils:
- Synthetic PAO specific for scroll
- Viscosity ISO 32 or 46 typical
- Verify compatibility with manufacturer
Tip Seals
Exclusive to scroll, critical for efficiency:
| Symptom | Probable Cause |
|---|---|
| Capacity loss | Tip seal wear |
| Discharge temperature increase | Internal leakage |
| Higher energy consumption | Internal recirculation |
| Different noise | Metal-to-metal contact |
Typical service life:
- Lubricated: 8,000-16,000 hours
- Oil-free: 4,000-8,000 hours
Bearings
| Type | Location | Typical Life |
|---|---|---|
| Main bearing | Crankshaft | 40,000-80,000 h |
| Radial bearing | Scroll support | 40,000-80,000 h |
| Thrust bearing | Axial load | 40,000-80,000 h |
Failure signs:
- Metallic noise
- Increased vibration
- Elevated temperature
- Excessive play
Problem Diagnosis
Capacity Loss
| Cause | Verification | Solution |
|---|---|---|
| Clogged filter | Pressure differential | Replace |
| Worn tip seals | Visual inspection | Replace |
| Check valve leak | Retention test | Repair/replace |
| System leak | Ultrasound | Repair |
Overheating
| Cause | Verification | Solution |
|---|---|---|
| Blocked ventilation | Air flow | Clean/clear |
| Very hot environment | Ambient temperature | Improve ventilation |
| Excessive pressure | Gauge | Adjust/verify |
| Low oil (lubricated) | Level | Top up |
| Damaged tip seals | Inspection | Replace |
Abnormal Noise
| Sound | Probable Cause | Action |
|---|---|---|
| Knocking | Damaged bearing | Urgent replace |
| Whistling | Internal leak | Inspect scrolls |
| Squealing | Lack of lubrication | Check oil |
| Electrical hum | Motor | Check connections |
| Vibration | Imbalance, mounting | Check anchoring |
Excessive Vibration
| Cause | Verification | Solution |
|---|---|---|
| Loose mounting | Anchor bolts | Tighten |
| Misalignment | Coupling | Realign |
| Damaged bearing | Noise, temperature | Replace |
| Imbalance | Damaged component | Internal inspection |
Maintenance Kits
Manufacturers offer pre-packaged kits:
Minor Service Kit (2,000-4,000 h)
├── Inlet filter
├── Oil filter
├── Oil (correct quantity)
├── Drain O-rings
└── Instructions
Major Service Kit (8,000-16,000 h)
├── Everything from minor kit
├── Tip seals (complete set)
├── Housing gaskets
├── Discharge check valve
└── Detailed instructions
Overhaul Kit (40,000+ h)
├── Everything from major kit
├── Bearings (set)
├── Oldham coupling
├── Oil seals
├── Scrolls (if needed)
└── Rebuild manual
Special Tools
| Tool | Use |
|---|---|
| Bearing puller | Removal without damage |
| Seal installer | Correct mounting |
| Torque wrench | Specified tightening |
| Feeler gauges | Check clearances |
| Dial indicator | Check runout |
Maintenance Records
Data to Record
| Field | Example |
|---|---|
| Date | 2024-03-15 |
| Operating hours | 4,523 |
| Task performed | Inlet filter change |
| Parts used | Filter P/N 12345 |
| Technician | J. Smith |
| Observations | Filter very dirty |
Tracking Indicators
| Indicator | Target |
|---|---|
| Availability | greater than 98% |
| MTBF | greater than 8,000 h |
| MTTR | less than 4 h |
| Maintenance cost/HP/year | less than $100 |
Maintenance Cost Comparison
| Compressor Type | Cost/HP/Year |
|---|---|
| Scroll | $50-80 |
| Piston | $100-150 |
| Lubricated screw | $80-120 |
| Oil-free screw | $120-180 |
Preventive Maintenance
A well-executed preventive maintenance program can:
- Extend service life 50%+
- Reduce unplanned failures 80%+
- Maintain original efficiency
- Reduce total cost of ownership