Hertz Kompressoren HGS-HSC Series
Compact belt-driven, fixed-speed oil-injected screw range covering 2.2–75 kW for shops and light industry.
Type
Oil-flooded rotary screw
Power
3–100 hp (2.2–75 kW)
Flow
7–441 cfm (0.2–12.5 m³/min)
Pressure
109/123/145/188 psig (7.5 / 8.5 / 10 / 13 bar)
Cooling
air
Drive
belt
Lubrication
oil-flooded
Models
HGS-HSC 2.2 – 75 kW (compact belt-driven, fixed speed)
Typical applications
- Small machine shops
- Workshops and service bays
- Light manufacturing
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: Hertz screw compressor fluid per the unit manual
Change interval: 2,000–4,000 hr typical on the small frames
Wear parts
| Category | Interval | Source |
|---|---|---|
| Air filter element | 2,000 hr or on ΔP | |
| Oil filter | 2,000 hr | |
| Oil separator element | 4,000 hr | |
| Drive belts | Inspect quarterly | |
| Cabinet fan / filter mat | Clean quarterly |
Consumable part numbers change by revision and region — pull the current number from the OEM portal.
Preventive maintenance
Daily
- Check fluid level in sight glass at running temp
- Listen for unusual noise / vibration
- Check discharge pressure & temperature vs baseline
- Verify condensate drain function
- Log package amps if metered
Weekly
- Blow down receiver and drain traps
- Check for oil carryover at first drop leg
- Inspect for fluid or air leaks around airend and separator tank
- Verify safety valve is not weeping
Every 2,000 hr / 6 mo
- Change fluid filter
- Change air filter (or sooner per ΔP)
- Sample fluid for TAN / metals / water
- Clean cooler exterior with low-pressure air (never > 30 psi against fins)
Every 4,000 hr / 12 mo
- Change separator element
- Change fluid
- Inspect scavenge line & orifice for coking
- Check coupling / belt alignment & wear
- Torque electrical lugs to spec (typ. 45–75 in-lb #4–2/0 AWG)
Every 8,000 hr
- Rebuild inlet valve
- Rebuild minimum-pressure check valve
- Regrease or replace motor bearings per OEM interval
- Verify safety valve setpoint against gauge
Common faults & first checks
- Heat soak in tight closet installs — the small cabinets are ventilation-sensitive
- Belt slip after the first few hundred hours if tension is not re-checked
- Short-cycling when the receiver is undersized for the duty
Controller(s)
- Hertz Screw Compressor Controller (HSC / HSC-D / HGS panel) — Backlit alphanumeric LCD control panel with membrane keypad and status LEDs. Larger frames ship with the graphic touch-style panel. Exact panel varies by frame, build year and region — confirm against the panel label.
Strengths
- Broad small-to-mid coverage in a compact cabinet
- Tank-mount and dryer combinations available
- Simple, serviceable belt drive
Weaknesses
- Fixed speed only
- Tight cabinets mean cramped service access on the smallest frames
Field notes
Range from the public HGS-HSC brochure. Frame-by-frame capacity varies significantly across this series — check the data plate.