ELGi EN Series oil-flooded screw

EN04 – EN75 (5–100 hp), fixed speed and VFD variants

ELGi EN Series oil-flooded screw

ELGi's mainstream oil-flooded screw line covering 5–100 hp in fixed-speed and variable-speed builds, controlled by the Neuron family of controllers.

Type
Oil-flooded rotary screw
Power
5–100 hp (4–75 kW)
Flow
20–450 cfm depending on frame and pressure
Pressure
100–190 psig (7–13 bar)
Cooling
air
Drive
direct
Lubrication
oil-flooded
Models
EN04 – EN75 (5–100 hp), fixed speed and VFD variants
Motor efficiency
IE3 / premium-efficiency TEFC standard on current builds.
Starter
DOL on small frames, Wye-Delta on mid frames, VFD on the variable-speed line.
Control modes
  • Load/unload
  • Continuous
  • Auto stop/start
  • VFD (variable speed variants)
Typical applications
  • General plant air
  • Automotive and fabrication shops
  • Packaging lines

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: ELGi-approved screw compressor fluid (mineral or synthetic per the machine chart)
Change interval: Mineral ~2,000 hr; synthetic 4,000–8,000 hr per the chart

Fluid selection is temperature and duty dependent — use the machine's own chart, not a generic one.

Wear parts
CategoryIntervalSource
Air filter element2,000 hr or on ΔP
Oil filter2,000 hr (first change earlier after commissioning)
Separator element4,000 hr or on rising ΔP
Inlet valve kitRebuild at 8,000 hr
Minimum pressure valve kitRebuild at 8,000 hr
Motor bearingsRegrease per the plate; replace per OEM hours

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
  • High airend discharge temperature — cooler face fouling, low fluid, or a stuck thermal valve
  • Won't load — Neuron output, load solenoid coil, or a plugged pilot line
  • High separator ΔP — element past interval or wrong fluid
  • Motor overload trip on Y-Δ transition — contactor timing or a weak transition contactor
Controller(s)
  • ELGi Neuron IIBacklit LCD with membrane keys and status LEDs
  • ELGi Neuron XTGraphic LCD showing package discharge pressure, discharge temperature and machine status
Strengths
  • Value pricing against the majors
  • Simple, serviceable package layout
  • Neuron controllers are straightforward to navigate
Weaknesses
  • Parts availability depends on local distributor strength
  • Documentation is thinner than the top-tier brands
Field notes

Range and control detail from published ELGi literature and the public Neuron manuals. Confirm frame-specific CFM against the nameplate.