The Castair I15312HC2-S is a 15-horsepower, 3-phase industrial air compressor on a 120-gallon horizontal tank with the C2 pump running at 898 RPM and a factory-mounted magnetic motor starter. At 15HP, this machine is a step up from the 10HP line in every meaningful way — more air, bigger motor, higher capacity for shops that have outgrown a 10HP unit. The C2 pump at 898 RPM delivers 45.3 CFM at 175 PSI, which is roughly 30% more output than a 10HP C2 unit at the same pressure. The horizontal tank at 69x24x50 inches keeps the height manageable when ceiling clearance is limited.
Who Needs This Compressor
High-volume automotive shops, production facilities, and industrial operations on 3-phase power that run multiple high-CFM tools simultaneously. Body shops running continuous spray operations alongside impact wrenches, shops with sandblasting equipment, production lines with multiple pneumatic actuators, or any facility where a 10HP unit is running continuously and struggling to keep up. At 45.3 CFM at 175 PSI, the I15312HC2-S can supply 5-6 standard impact wrenches or maintain a sandblaster without significant pressure drop.
Pump Features
- All cast iron construction — cylinders, heads, crankcase.
- 898 RPM pump speed — within the slow-speed industrial range. Higher than the 15HP C3 pump (795 RPM) but still well below the 1100+ RPM of budget compressors.
- Tapered roller bearings at both ends of the crankshaft.
- Steel connecting rods with automotive-type insert bearings — at crankshaft and wrist pin.
- Disc and spring valves.
- 4-ring pistons.
- Centrifugal unloader — loadless starts.
Tank, Motor, and Controls
- 120-gallon horizontal ASME tank — powder coated, channel base, 69x24x50 inches overall.
- ASME safety valve.
- 1725 RPM industrial motor, 15HP — 15% service factor minimum.
- Totally enclosed metal belt guard.
- Copper discharge tube or stainless-steel braided flex line.
- Magnetic motor starter — included, factory mounted.
15HP 3-Phase Industrial Line Comparison
- I15312VC2-S — 120-gallon vertical, C2 pump (898 RPM), 45.3 CFM @175 PSI, 44x30x75 in., 980 lbs, with starter.
- I15312HC2-S (this unit) — 120-gallon horizontal, C2 pump (898 RPM), 45.3 CFM @175 PSI, 69x24x50 in., 980 lbs, with starter.
- I15312VC3-S — 120-gallon vertical, C3 pump (795 RPM, larger/slower), 50.2 CFM @175 PSI, 44x30x82 in., 1185 lbs, with starter.
- I15312HC3-S — 120-gallon horizontal, C3 pump (795 RPM), 50.2 CFM @175 PSI, 69x24x62 in., 1185 lbs, with starter.
Factory Options
- Low oil shutdown — #6304M.
- Hour meter — #HRM460M (460V) or #HRM75M (230V).
- Electronic auto drain — #SDV03M.
- Dual control — #DC2.
- Intake noise silencer — #SA100x2M.
- Belt tensioner — #254DM (15HP).
- Beltguard aftercooler — #BGAC2M (50 CFM, fits 15HP).
- All Options C2 package — #AOC2 (10% off).
- Vibration pads — #VP1004, set of 4.
- Right from the Start Kit — #RFS001 (C1, C2).
Technical Specifications
- Model Number: I15312HC2-S
- Horsepower: 15 HP
- Phase: 3-phase
- Tank Capacity: 120 gallons, horizontal
- Pump RPM: 898
- CFM @ 0 PSI: 55.0
- CFM @ 175 PSI: 45.3
- Max Pressure: 175 PSI
- Dimensions (LxWxH): 69 x 24 x 50 inches
- Weight: 980 lbs
- Motor Speed: 1725 RPM
- Motor Service Factor: 15% minimum
- Tank Certification: ASME
- Magnetic Starter: Included (factory mounted)
- Pump Configuration: C2
Why Buy From Air Compressor Factory Direct?
We have specialized in industrial air compressors since 2016. At this price point, getting the configuration right before you order matters. Call us and we will confirm whether the C2 or C3 pump, horizontal or vertical tank, is the right match for your shop layout and air demand. Free shipping, free pre-sale technical support, full manufacturer warranty.
Call 866-217-0063 for quick answers and help!
