The Castair I738HC2 is a 7.5 HP, 3-phase industrial air compressor on an 80-gallon horizontal ASME tank with the C2 pump — without the factory-mounted magnetic motor starter. It's identical to the I738HC2-S in every other respect: same C2 pump, same motor, same 80-gallon horizontal tank, same 585 RPM shaft speed, same 28.1 CFM at 175 PSI output, same 730 lb shipping weight. The starter is simply not included here.
Order this model if your shop already has a motor control panel that will handle overload protection, or if your electrician will source and mount the starter separately. For the starter-included version, see the I738HC2-S. If you're not sure which to order, call us and we'll walk through your electrical setup.
Pump Features — Cast Iron C2 Two-Stage V4
- All cast iron V4 cylinder configuration: Four cylinders in a V arrangement — higher displacement than the C1, producing more CFM at lower RPM
- Slow 585 RPM operation: Lower shaft speed means less heat and less wear than faster-turning pump designs
- Tapered roller bearings at both crankshaft ends: Superior support for the larger pump's loads under belt drive and two-stage compression
- Precision steel connecting rods: Automotive-type insert bearings at crankshaft, needle bearings at wrist pin
- Disc and spring valves: Field-serviceable, reliable under continuous duty cycling
- 4-ring pistons: Less oil carry-over into the discharge air
- Centrifugal unloader: No-load start every time, protecting motor and pump
Tank and Frame Features
- 80-gallon horizontal ASME-rated tank: Powder coated, channel-supported base for stable floor installation
- ASME safety valve: Factory installed, rated for working pressure
- Metal belt guard: Fully enclosed — not a plastic clip-on
- Copper discharge and unloader tube: Better heat dissipation than rubber or plastic lines
Motor
- 1,725 RPM heavy-duty industrial motor: Full 15% service factor — continuous duty rated
- 3-phase: Requires magnetic motor starter for overload protection (not included — see -S version for factory-mounted starter)
What's in the Box
- Castair I738HC2 compressor assembly (C2 pump, motor, 80-gal horizontal tank, belt drive, belt guard)
- ASME safety valve (installed)
- Copper discharge and unloader tube (installed)
- Pressure switch (installed)
- Magnetic motor starter not included — order I738HC2-S for the starter-included version
Available Configurations — 7.5HP 3-Phase Industrial Lineup
- I738HC1-S: 7.5HP, 3-phase, 80-gal horizontal, C1 pump, 895 RPM, 24.8 CFM@175PSI, 64x20x48 in., 625 lbs, magnetic starter included
- I738HC1: Same as above without factory-mounted magnetic starter
- I738HC2-S: 7.5HP, 3-phase, 80-gal horizontal, C2 pump, 585 RPM, 28.1 CFM@175PSI, 64x20x46 in., 730 lbs, magnetic starter included
- I738HC2: Same as above without factory-mounted magnetic starter
- I738VC1-S: 7.5HP, 3-phase, 80-gal vertical, C1 pump, 895 RPM, 24.8 CFM@175PSI, 32x24x74 in., 625 lbs, magnetic starter included
- I738VC1: Same as above without factory-mounted magnetic starter
- I738VC2-S: 7.5HP, 3-phase, 80-gal vertical, C2 pump, 585 RPM, 28.1 CFM@175PSI, 40x24x74 in., 730 lbs, magnetic starter included
- I738VC2: Same as above without factory-mounted magnetic starter
- I7312HC2-S: 7.5HP, 3-phase, 120-gal horizontal, C2 pump — maximum reserve for high-demand shops
When Does a Shop Need This vs. Stepping Up or Down
The I738HC2-S is right for your shop if: You have 3-phase power, need the higher CFM output of the C2 pump (28.1 CFM@175PSI), and want an 80-gallon tank for adequate reserve. This is the go-to unit for shops running spray guns, DA polishers, or three-bay operations alongside general hand tools. The C2 pump at 585 RPM runs quieter and cooler than the C1 at 895 RPM.
Step down to I738HC1-S if your shop's sustained air demand is lower — general automotive service with impacts and ratchets doesn't always need the C2's extra CFM, and the C1 is a lighter, simpler unit.
Step up to I7312HC2-S (120-gallon) for maximum reserve — if you're painting multiple vehicles per day or running continuous sandblasting, the 120-gallon tank keeps the compressor from short-cycling.
Technical Specifications
- Model: I738HC2
- Horsepower: 7.5 HP
- Phase: 3-phase
- Tank Capacity: 80 gallons
- Tank Type: Horizontal, ASME-rated, powder coated
- Tank Dimensions: 64 x 20 x 46 in. (L x W x H)
- Shipping Weight: 730 lbs
- Pump Model: C2 (two-stage, cast iron, V4)
- Pump RPM: 585
- CFM @ 0 PSI: 35.0
- CFM @ 175 PSI: 28.1
- Max Working Pressure: 175 PSI
- Motor Speed: 1,725 RPM
- Starter: Not included (see I738HC2-S for starter-included version)
- Compatible Starter (208/230V): S72 with B36 heaters
- Compatible Starter (460V): S74 with B22 heaters
- Discharge Tube: Copper
- Belt Guard: Metal, fully enclosed
Why Buy From Air Compressor Factory Direct?
We specialize in industrial and commercial air compressors and have been at it since 2016. When you call, you're talking to someone who knows the Castair lineup, can tell you whether the C1 or C2 pump fits your shop's CFM requirements, and can help you decide between horizontal and vertical tank configurations for your space. Free shipping, free technical support at 866-217-0063, full Castair manufacturer warranty. Call us before you buy if you have questions about which configuration is right for your shop.
Call 866-217-0063 for quick answers and help!
