Powerex SES / SLS Scroll (Oil-Less)
Multi-head oil-less scroll compressor skids for medical, dental, and lab air. Redundant heads sequenced by Logix.
Type
Oil-less scroll
Power
3–15 hp per module; skids to 90+ hp
Flow
8–50 cfm per module
Pressure
100–145 psig
Cooling
air
Drive
direct
Lubrication
oil-less
Models
SES03, SES05, SES07, SLS03, SLS05, SLS07 (modules 3–15 hp each, packaged as multi-head skids)
Years produced
Powerex scroll medical / lab air packages since 1990s.
Sound level
~62–70 dB(A) @ 1 m per module — very low compared to screws or recips.
Ambient range
40–104 °F.
Motor efficiency
TEFC premium efficiency motors.
Warranty
Powerex 5-year limited on scroll modules typical.
Control modes
- Pressure-based head cycling
- Hour equalization / lead-lag rotation
Typical applications
- NFPA 99 medical air
- Dental / lab air
- Semiconductor test benches
Specs & intervals below are from publicly published OEM literature and long-standing field practice. Torque values, exact revision-dated part numbers, and safety-critical settings vary by serial number — always cross-check the unit’s OEM manual and nameplate before ordering parts or performing service.
Fluid
Spec: None (oil-less)
Change interval: N/A
Wear parts
| Category | Interval | Source |
|---|---|---|
| Tip seals (scroll orbiting seal) | 10,000 hr typical (verify per module) | |
| Inlet filter (per head) | 2,000 hr | |
| Cooling fan bearings | As needed | |
| Check valves (per head) | Inspect at each tip seal service | |
| Dust seals | At each tip seal replacement |
Consumable part numbers change by revision and region — pull the current number from the OEM portal.
Preventive maintenance
Daily
- Log per-head hours (verify sequencer rotates)
- Check tank drain function
- Listen for scroll bearing noise
2,000 hr
- Change inlet filter per head
- Verify cooling airflow
- Log discharge temp per head
10,000 hr
- Replace tip seals per OEM procedure (clean-room-like conditions)
- Inspect check valves
- Replace head fan if worn
Common faults & first checks
- Head temp high — cooling airflow blocked or tip seals worn
- Uneven hour distribution — Logix sequencer rotation failure
- Loss of one head still runs — verify sequencer alarm relays wired to plant BMS
Known issues & field notes
- Tip seal service is a precision procedure — over-torqued fixed scroll bolts crack the housing
- Skid must remain clean & dust-free in mechanical rooms — install with proper intake filtration
Controller(s)
- Logix (aftermarket / OEM shared) — 2-line 20-char LCD with 4 status LEDs.
Strengths
- 100% oil-free — ideal for medical/lab/electronics
- Redundancy from multiple heads
- Low vibration
- Quiet
Weaknesses
- Tip seal service is precise and OEM-training preferred
- Per-cfm cost higher than screw
Field notes
Powerex is the leading NA scroll compressor for NFPA 99 medical air and laboratory use.