Hertz Kompressoren HSC Series
Hertz's belt-driven, fixed-speed oil-injected rotary screw line in the 90–160 kW class, with electronic control, built-in Modbus, weekly scheduling and two-unit master/slave sequencing.
- General manufacturing
- Textile
- Food and beverage utility air
- Metal fabrication
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.
Do not blend fluid types. Confirm the exact grade on the sump decal before topping up.
| Category | Interval | Source |
|---|---|---|
| Air filter element | 2,000 hr or on ΔP | |
| Oil filter | 2,000 hr | |
| Oil separator element | 4,000 hr | |
| Compressor fluid | Per fluid grade / panel counter | |
| Drive belts + tensioner | Inspect quarterly; replace on cracking or glazing | |
| Inlet valve service kit | 8,000 hr | |
| Minimum-pressure valve kit | 8,000 hr |
Consumable part numbers change by revision and region — pull the current number from the OEM portal.
- 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
- 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
- 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)
- 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)
- Rebuild inlet valve
- Rebuild minimum-pressure check valve
- Regrease or replace motor bearings per OEM interval
- Verify safety valve setpoint against gauge
- High discharge temperature in hot rooms — cooler pluggage plus a lazy thermostatic valve
- Belt wear / tension loss on the belt-driven frames
- Separator ΔP climbing early when the wrong fluid is topped in
- Phase-sequence lockout after a plant electrical change
- 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.
- Belt drive lets the airend be pulley-matched to pressure
- Standard Modbus and two-unit master/slave without an external sequencer
- Optional integrated dryer and heat recovery
- Belts are an extra wear item vs direct drive
- Service PINs and full manuals are distributor-gated
- Dealer/parts network is thinner in North America than the major brands
Specs above are from the public Hertz HSC brochure. A separate HSC 16 bar variant covers 11–22 kW at 16 bar. Always verify frame-specific capacity and pressure against the unit's data plate.