Castair 7.5 HP 3-Phase Rotary Screw Air Compressor — Horizontal Tank, 230/460V (R738HP75-460)
The Castair R738HP75-460 is the 460V 3-phase version of the R738HP75 rotary screw compressor — same 7.5 HP air end, same 80-gallon horizontal ASME tank, same 31 CFM at 100 PSI output, wired from the factory for 460V 3-phase service. If your facility runs 460V 3-phase (common in industrial buildings, larger body shops, and manufacturing facilities), this is the correct model to order. Running a 230V unit on 460V service — even through a transformer — is not recommended. Order the right voltage from the start.
Manufacturer specifications pending confirmation on the 230/460V dual-rating in the product name. Based on Castair catalog data, the R738HP75 series is 230V standard with 460V available as a factory option. Contact us at 866-217-0063 to confirm your exact voltage configuration before ordering.
Same Machine, Right Voltage
Everything about the R738HP75-460 is identical to the R738HP75-230 except the electrical configuration. The 460V wiring allows the motor to draw half the amperage at twice the voltage compared to the 230V version — this means smaller wire runs, smaller breakers, and lower I2R losses over longer runs from your panel to the compressor. In shops where the compressor is 50+ feet from the panel, 460V is often the better choice even when both voltages are available.
Air End and Drive System
- Duty cycle: 100% — continuous operation rated
- Air end: Rotary screw, single solenoid control — no computers, no lockout codes
- Motor: Heavy-duty industrial 1725 RPM with 15% service factor or higher
- Drive: Off-shelf V-belts with adjustable belt tightener
- Lubrication: Factory-filled 4,000-hour / 1-year synthetic CAST-LUBE oil
- Oil filter: Spin-on automotive-type
- Air filter: Automotive-style paper element
Controls and Safety
- Pressure control: Single solenoid, no PLC or computer
- Gauges: Pressure and temperature gauges, easy-read standard
- High pressure shutdown: Standard
- Dual high temperature shutdown: Standard
- 10-minute shutdown timer: Standard — saves electricity when air demand drops
- No lockout codes: Field-serviceable without dealer involvement
Tank and Cooling
- Tank capacity: 80 gallons, horizontal
- Tank certification: ASME (USA-made)
- Air/oil separator: Built-in with spin-on filter
- Aftercooler: Air-cooled aftercooler and oil cooler, removable for cleaning
- Plumbing: Off-shelf copper piping throughout
Electrical
- Voltage: 460V, 3-phase (230V version: R738HP75-230)
- Starter: Name-brand magnetic starter, factory mounted and wired — connect power and run
Maintenance
- Hour meter: Standard for maintenance scheduling
- Oil changes: Spin-on oil and separator filters — no special tools
- Belt service: Off-shelf V-belts, adjustable tensioner
- PM kit: MKD3-4 (D3, D31, D4 air ends, 5-10 HP range) — 10% savings vs. individual items
What Is in the Box
- Castair R738HP75-460 rotary screw compressor, fully assembled
- 80-gallon horizontal ASME tank
- Air-cooled aftercooler and oil cooler
- Magnetic starter and controls, factory wired for 460V
- Hour meter
- Pressure and temperature gauges
- Factory fill CAST-LUBE synthetic oil
Vibration pads, ball valve, and flex hose available as factory-mounted options or separately.
Available Configurations
- R738HP75-230 — Same unit, 230V 3-phase
- R738HP75-460 (this unit) — 460V 3-phase, 80 gal horizontal, 31 CFM, 64x32x44, 546 lbs
- R738VP75-460 — Same specs, vertical tank, 34x26x70, 546 lbs
- R1038HP75 — 10 HP, 80 gal horizontal, 40 CFM at 100 PSI
- R15312HP75 — 15 HP, 120 gal horizontal, 52 CFM
When Does a Shop Need This vs. Stepping Up or Down?
Order this model if: Your facility has 460V 3-phase service and you need a mid-size rotary screw compressor with horizontal layout. The 460V wiring reduces wire gauge requirements on long runs from your electrical panel and is standard in many industrial facilities.
Step up to R1038HP75 if: You need more than 31 CFM — three or more heavy air tools running simultaneously.
Step down to R538HP75 if: Your air demand is under 20 CFM consistently.
Choose 230V instead if: Your facility is wired for 230V 3-phase — do not assume a transformer will work cleanly with the motor starter on this unit. Order the correct voltage.
Technical Specifications
- Model: R738HP75-460
- Horsepower: 7.5 HP
- Phase: 3-phase
- Voltage: 460V (230V available as R738HP75-230)
- CFM @ 100 PSI: 31
- Standard operating pressure: 135 PSI (150 or 175 PSI available)
- Duty cycle: 100%
- Tank size: 80 gallons, horizontal
- Tank certification: ASME (USA-made)
- Dimensions (LxWxH): 64" x 32" x 44"
- Weight: 546 lbs
- Motor speed: 1725 RPM
- Motor service factor: 15% or higher
- Oil: CAST-LUBE synthetic, 4,000-hour / 1-year service interval
- Warranty: 2 years on air end, electric motor, and tank
Why Buy From Air Compressor Factory Direct?
- Castair specialists: Full lineup, full parts support
- Free shipping to commercial addresses
- Free tech support: 866-217-0063 — real answers on voltage, sizing, and installation
- Full 2-year warranty on air end, motor, and tank
- Honest guidance: Call us if you are unsure whether 230V or 460V is right for your shop
Call 866-217-0063 for quick answers and help!
