The Castair D10324HC3-S is the top configuration in the three-phase 2x10HP duplex lineup: 240-gallon horizontal ASME tank, HC3 pump running at 570 RPM, three-phase power, 70 CFM at 175 PSI combined, 2,190 lbs, 94" x 30" x 64". This is a production shop compressor — the unit you specify when you need maximum tank capacity, the most durable pump configuration, three-phase efficiency, and duplex redundancy all in one machine. If your shop runs hard every day, this is the right long-term investment.
Why This Is the Top of the 2x10HP Duplex Line
Every element of the D10324HC3-S is specified for durability and high utilization:
- Three-phase power: Lower running amperage, cooler motor operation, no capacitor start components to fail, longer motor service life compared to single-phase at this HP rating
- HC3 pump at 570 RPM: The slowest and largest displacement pump in the 2x10HP family — lowest heat generation, quietest operation, longest expected valve and ring life
- 240-gallon receiver: Double the storage of the 120-gallon versions — fewer pump start cycles, stable supply pressure during extended high-draw operations, less pressure sag at the tool
- Duplex configuration: Two complete pump/motor sets — if one pump is down for maintenance, the shop keeps running at partial capacity
Pump and Motor Specifications
- Configuration: Duplex (two pumps, two motors)
- Total HP: 20 HP (2 x 10 HP)
- Phase: Three-phase
- Pump RPM: 570 (HC3 pump)
- CFM at 0 PSI: 90 CFM combined
- CFM at 175 PSI: 70 CFM combined
- Max Pressure: 175 PSI
- Stage: Two-stage
Tank and Physical Specs
- Tank Capacity: 240 gallons, horizontal ASME
- Dimensions (LxWxH): 94" x 30" x 64"
- Weight: 2,190 lbs
- Tank Finish: Powder coated
- Safety Valve: ASME rated, installed
- Magnetic Starter: Mounted and wired (factory installed)
Cast Iron Pump Features
- All cast iron construction — no aluminum pump bodies, no compromises on longevity
- HC3 pump at 570 RPM — the slowest, largest displacement pump in this family
- Tapered roller bearings at both ends of crankshaft for superior support
- Precision steel connecting rods with automotive-type rod insert bearings at crankshaft and wrist pin
- Disc and spring valves for easy service, high efficiency, and reliability
- 4-ring pistons for higher efficiency and less oil carry-over
- Centrifugal unloader for loadless start-up every time
Three-Phase 2x10HP Duplex — Full Lineup Comparison
- D10312HC2-S — 3-phase, 120gal, HC2 758 RPM, 85x28x57, 1,410 lbs — entry three-phase configuration
- D10324HC2-S — 3-phase, 240gal, HC2 758 RPM, 85x30x64, 1,760 lbs — larger tank, same RPM
- D10312HC3-S — 3-phase, 120gal, HC3 570 RPM, 94x28x57, 1,740 lbs — slower pump, smaller tank
- D10324HC3-S — 3-phase, 240gal, HC3 570 RPM, 94x30x64, 2,190 lbs — maximum configuration (this unit)
When Does a Shop Need This
The D10324HC3-S is specified for: Production shops running multiple shifts, collision centers with continuous spray operations, industrial facilities with sustained high CFM demand, and any application where the compressor is expected to run for years at high utilization without major pump rebuilds. Three-phase service is required.
Step down to D10312HC3-S if 120 gallons of storage is sufficient for your demand — same pump, same phase, less weight and floor space.
Step down to D10324HC2-S if the HC3 pump's noise and temperature benefits are not priorities — same tank, same phase, lighter and less expensive.
If you do not have three-phase service, the D10124HC3-S (single-phase) is the equivalent with the same pump and tank.
Technical Specifications
- Model: D10324HC3-S
- Manufacturer: Castair (Cast Air, Inc.) — Spicer, Minnesota
- Total HP: 20 HP (2 x 10 HP)
- Phase: Three-phase
- Pump RPM: 570 (HC3)
- CFM @ 0 PSI: 90
- CFM @ 175 PSI: 70
- Tank: 240 gallon, horizontal, ASME, powder coated
- Dimensions (LxWxH): 94" x 30" x 64"
- Weight: 2,190 lbs
- Magnetic Starter: Included, factory mounted and wired
- Safety Valve: ASME rated, installed
Why Buy From Air Compressor Factory Direct?
We have been selling Cast Air industrial compressors since 2016. At over $13,000, this is not an impulse purchase — we can help you confirm the D10324HC3-S is the right specification for your electrical service, CFM requirements, and floor layout. We also help with factory-mounted options like low oil control, auto drains, and aftercoolers. Free shipping, free technical support at 866-217-0063, full manufacturer warranty.
Call 866-217-0063 for quick answers and help!
Frequently Asked Questions
What is the advantage of a duplex compressor over a single-unit setup?
The D10324HC3-S runs two 10 HP cast iron pumps on a shared 240-gallon tank, giving you 100% redundancy and load-sharing in a single footprint. Instead of one 20 HP motor cycling hard under continuous demand, each pump shares the load, which reduces heat buildup and extends pump life. For shops running air tools, spray booths, or pneumatic equipment continuously, that duty cycle difference is significant.
Can one pump on the D10324HC3-S run independently if the other is down for service?
Yes. Each pump on the D10324HC3-S has its own motor, pressure switch, and unloader valve, so either unit can operate solo while the other is locked out for maintenance or repair. You will see a reduction in total CFM output, but the system stays online — that is the core practical benefit of a duplex configuration. Single-pump capacity on this unit is sufficient to keep most shops functional during scheduled downtime.
Does the D10324HC3-S include an alternator, and why does it matter?
The D10324HC3-S is available with an alternating controller that automatically rotates which pump leads each cycle, equalizing run hours across both units. Without alternation, one pump accumulates significantly more hours than the other, which means uneven wear and staggered service intervals. With an alternator, both pumps age at the same rate, and you service them on the same schedule — simpler maintenance, more predictable part replacement.
What happens to production if one pump on the D10324HC3-S fails?
The working pump continues to run and maintains pressure in the 240-gallon tank — the system does not shut down. You lose roughly half your CFM capacity, but the large tank volume buffers demand spikes and keeps pressure stable for lighter loads. This fail-operational design is why duplex units are specified for critical production environments where a compressor going fully offline is not acceptable. Call us at 866-217-0063 if you need help diagnosing a pump issue on this unit — we stock Cast Air parts and can walk you through it.
Is the maintenance schedule for the D10324HC3-S different from a single-pump compressor?
The service intervals per pump are the same — oil changes, valve inspections, belt tension, and air filter service follow standard Cast Air cast iron pump schedules. The difference is that with an alternator installed, both pumps accumulate hours at the same rate, so you service both simultaneously rather than tracking separate clocks. Without alternation, check hour meters on each pump independently and service based on actual run time, not calendar dates.
