Heavy Duty Shop Air Compressor Industrial Series - Model No. I10312HC2-S

Castair I10312HC2-S — 10 HP Three-Phase Industrial Air Compressor, 120-Gallon Horizontal Tank, C2 Pump with Mounted Starter

The Castair I10312HC2-S is a 10 HP three-phase industrial air compressor with a 120-gallon horizontal ASME tank and factory-mounted magnetic motor starter. The cast iron C2 two-stage pump runs at 758 RPM, producing 45.0 CFM at 0 PSI and 35.0 CFM at 175 PSI. At 860 lbs and 69 x 24 x 50 inches, it is 15 lbs lighter than the single-phase equivalent (I10112HC2-S at 875 lbs) — three-phase motors are physically smaller for the same output.

If your facility has three-phase power, there is no practical reason to run a single-phase motor on a 10 HP compressor. Three-phase motors run cooler under load, start with less inrush current, require less derating at high ambient temperatures, and outlast single-phase motors in hard continuous service. The I10312HC2-S has the same output as the single-phase equivalent but in a configuration better suited for industrial continuous duty.

Cast Iron Pump Engineering — Why This Matters for Shop Longevity

Every Castair Industrial Series compressor is built around their oversized cast iron pump. Here is what separates these from lighter-duty machines:

• All cast iron construction — cylinder heads, crankcase, and cylinders are cast iron throughout. Cast iron manages heat better than aluminum and wears far more slowly under continuous load.
• Tapered roller bearings at both ends of the crankshaft — not ball bearings. Tapered rollers handle both radial and thrust loads simultaneously, which is exactly what a reciprocating pump crankshaft sees in operation.
• Precision steel connecting rods with automotive-type insert bearings — at both the crankshaft journal and the wrist pin. These are the same bearing design used in automotive engines. They are replaceable when worn — not a throwaway assembly.
• Disc and spring valves — simpler to service than reed valves, more efficient at high discharge pressures, and more reliable over years of cycling.
• 4-ring pistons — two extra rings versus typical 2-ring piston designs. Better compression sealing, significantly less oil carry-over into the air stream.
• Centrifugal unloader — the pump starts unloaded on every cycle without exception. This reduces motor starting current, reduces wear on the motor and belts, and eliminates the hard-start problem common in compressors that attempt to restart against pressure.

Three-Phase Motor Advantages

• Lower starting current — three-phase motors spread starting load across three legs. Single-phase motors draw substantially higher inrush current on startup, stressing the electrical system and motor windings.
• Runs cooler under load — heat is the primary motor failure mechanism. A three-phase motor at 10 HP runs cooler than a single-phase motor at the same load.
• More compact motor — same 10 HP in a physically smaller frame than single-phase equivalent
• Better for continuous duty — shops running the compressor all day should use three-phase if available
• Lighter unit — 860 lbs versus 875 lbs for the single-phase version

Tank, Motor, and Controls

• ASME-coded steel tank — powder-coated for corrosion resistance. ASME certification means the tank was designed and tested to a recognized pressure vessel standard, not just stamped with a number.
• ASME safety valve — factory-installed.
• Metal belt guard, totally enclosed — not a plastic cover.
• Copper discharge and unloader tubing or stainless-steel braided flex line — not plastic hose or rubber.
• Heavy-duty 1,725 RPM industrial motor with a minimum 15% service factor. This means the motor can sustain loads above its nameplate rating without tripping. In a shop where the compressor runs all day, the service factor is not a marketing number — it is the difference between a motor that lasts a decade and one that burns up in two years.

When to Choose Three-Phase vs. Single-Phase

• Always choose three-phase if your facility already has three-phase power — no cost premium for better performance
• Choose single-phase (I10112HC2-S) only if three-phase is not available and you cannot justify the cost of bringing it in
• Don''t install a phase converter to run a single-phase compressor — if you''re adding a phase converter anyway, run the three-phase motor directly

Who Needs This Unit

Shops and facilities with three-phase 230V or 460V service running 3-5 air tools simultaneously under continuous or near-continuous demand. Auto shops, body shops, manufacturing, fleet maintenance — wherever three-phase power is available and reliable compressed air is non-negotiable.

What's in the Box

• Castair I10312HC2-S compressor assembly (pump, motor, tank, factory-assembled)
• Factory-mounted and wired magnetic motor starter
• ASME safety valve (installed)
• Pressure switch (installed)
• Metal belt guard (installed)
• Copper discharge and unloader tubing or stainless-steel braided flex line (installed)
• Operator documentation

Factory-installed options available on this unit include: low oil shutdown control (#6304M), hour meter (#HRM75M for 230V or #HRM460M for 460V), air-operated auto drain (#ADVSM), electronic auto drain (#SDV03M), dual controls (#DC2 for C2 pumps), intake noise silencer (#SA100x2M for C2/C3), belt tensioner (#215DM for 10 HP), time delay (#TD100M for 230V), vibration isolation pads (#VP1004), beltguard aftercooler (#BGAC1M — 35 CFM, appropriate for 10 HP), and Right from the Start Kit (#RFS001 for C1/C2). Ordering all asterisk-marked options qualifies for 10% discount on options. Ask us about pre-configured option packages.

Technical Specifications

• Model: I10312HC2-S
• Horsepower: 10 HP
• Phase: 3-phase (three-phase)
• Tank capacity: 120 gallons
• Tank orientation: Horizontal (channel base)
• Pump type: C2 (two-stage cast iron)
• Pump RPM: 758
• CFM at 0 PSI: 45.0
• CFM at 175 PSI: 35.0
• Max working pressure: 175 PSI
• Motor speed: 1,725 RPM
• Motor service factor: 15% minimum
• Dimensions (L x W x H): 69 x 24 x 50 inches
• Weight: 860 lbs
• Tank certification: ASME
• Starter: Factory-mounted magnetic motor starter (included)
• Manufacturer: Castair (Cast Air Inc., Spicer, MN)

Available Configurations — Cast Air Industrial 10 HP Three-Phase Lineup

Single-phase versions (I101-series) are available if your facility only has single-phase 230V service.

Why Buy From Air Compressor Factory Direct?

We have been selling industrial air compressors since 2016 and carry the full Cast Air Industrial Series lineup. When you call us, you reach someone who can tell you whether the C2 or C3 pump is right for your application, what electrical service you need, which options are worth adding, and whether horizontal or vertical tank orientation fits your floor plan. We offer free shipping on qualifying orders, full manufacturer warranty support, and straight talk about which unit fits your shop — not a push toward the most expensive option.

Call 866-217-0063 for quick answers and help!