Cast Air R20312HG30-230 — 20HP 3-Phase Rotary Screw Air Compressor, 120-Gallon Horizontal Tank, 230V
The R20312HG30-230 is a production-grade rotary screw air compressor built for shops that are running hard all day. At 20HP, this is not a unit you buy because it was the next step up — you buy it because your operation genuinely demands it. High-production body shops, large fleet facilities, multi-lift operations, and industrial environments that run multiple air tools simultaneously are the natural fit for this class of compressor.
This specific configuration runs on 230V 3-phase power. Before ordering, read the electrical section below carefully — at 20HP on 230V, your electrical infrastructure requirements are significant.
20HP Rotary Screw — What This Class of Compressor Does
- Production-grade airflow: A 20HP rotary screw compressor in this class typically delivers approximately 80 CFM at 100 PSI — enough to run multiple spray guns, several impacts, pneumatic lifts, and other tools simultaneously without meaningful pressure drop. (Confirm exact CFM with us before purchase — specs should be verified against the manufacturer data sheet.)
- All-day duty cycle: Rotary screw compressors are built for 100% duty cycle. The R20312HG30 can run continuously through a full production day. This is the fundamental difference from a piston compressor — no cooldown cycles, no overheating, no pressure fluctuations from motor cycling.
- 120-gallon horizontal tank: The large receiver tank buffers demand spikes — when multiple tools kick on simultaneously, the stored volume absorbs the surge and the compressor catches up without starving downstream tools.
- Consistent pressure delivery: Spray gun operators in particular benefit from the steady, pulse-free airflow that a rotary screw delivers. Pressure consistency affects finish quality in ways that cycle counts on a piston unit simply cannot match.
Who Needs a 20HP Unit
- High-production body shops: Multiple spray booths, prep stations, and bodywork happening simultaneously. If your 15HP unit is cycling constantly and you are still seeing pressure drop at the gun, you have outgrown 15HP.
- Large fleet maintenance facilities: Running tire equipment, impact wrenches across multiple bays, pneumatic jacks, and chassis work all at once demands consistent high-volume airflow. Fleet operations at scale hit the ceiling of a 15HP unit quickly.
- Industrial and manufacturing operations: Pneumatic assembly, material handling, and continuous process air supply. This is the compressor class these environments require.
- Multi-lift shops running full capacity: Four or more lifts with techs working at the same time, air ratchets, impacts, and blow guns all pulling simultaneously — a 15HP unit struggles. The 20HP does not.
20HP vs. 15HP — When to Step Up
- Your 15HP unit runs continuously: If the compressor rarely cycles off during your workday, you are at the limit of that HP class. A unit running non-stop is not getting thermal recovery time and will wear faster.
- Pressure drop under peak load: If tools are noticeably weaker when multiple users are on air at the same time, your supply volume is insufficient for peak demand.
- Expansion plans: If you are adding bays, a spray booth, or additional equipment, size the compressor for where you are going, not where you are today.
- The 15HP is sufficient if: You have a moderate-demand shop — two or three bays, intermittent tool use, no spray work. Do not buy 20HP headroom you will never use. Call us if you are unsure which HP class fits your actual load.
230V 3-Phase Electrical Requirements — Read This Before Ordering
- High amperage at 230V: A 20HP motor at 230V 3-phase draws approximately 54–60 amps at full load. Your electrical panel must support a dedicated circuit of this size.
- Breaker sizing: Per NEC motor load requirements, the breaker will typically need to be sized at 175–250% of FLA — expect a 100–125A dedicated breaker for this circuit.
- Wire sizing: The wire run from panel to compressor must be sized for the amperage. Long runs require larger gauge wire to manage voltage drop. Have an electrician calculate this before rough-in.
- Compare to 460V: The R20312HG30-460 runs the same 20HP compressor at 460V 3-phase — at 460V, motor draw drops to approximately 27–30 amps, meaning smaller wire, smaller breaker, and less heat in the circuit. If your facility has 460V 3-phase available, it is strongly recommended for 20HP applications. The 230V configuration is the right choice only when 460V is not available in your building.
- Electrical coordination: Do not order this unit without first confirming your electrical service can support it. At this amperage, a licensed electrician must perform the installation.
120-Gallon Horizontal Tank
- Storage capacity: 120 gallons of compressed air storage provides significant buffering for demand spikes. The horizontal configuration is the standard layout for most shop installations — lower profile, easier to position against a wall.
- Drain management: At this output level, condensate production is substantial. Install an auto-drain valve on the tank to prevent water accumulation that can corrode the tank interior and contaminate downstream air lines.
- Placement: Allow adequate clearance around the unit for ventilation. A 20HP rotary screw generates considerable heat during operation — confined spaces will reduce performance and shorten service life.
Specifications
- Model: R20312HG30-230
- Compressor type: Rotary screw
- Horsepower: 20 HP
- Phase: 3-phase
- Voltage: 230V
- Tank configuration: Horizontal
- Tank capacity: 120 gallons
- Typical CFM output: Approximately 80 CFM at 100 PSI (confirm with manufacturer data sheet)
Note: Confirm exact CFM, operating pressure range, dimensions, and weight with us prior to purchase. We will pull the current Cast Air specification sheet for you.
Why Buy From OEM Diagnostic Tools?
- Specialist since 2016: We work with professional shops daily. We understand what a high-production body shop or fleet facility actually runs and can help you right-size your compressor investment.
- Free shipping: Freight on a 20HP compressor is not trivial. We include it.
- Free technical support: Call 866-217-0063. We will walk through your shop's air demand, confirm the right voltage option, and make sure you are not over- or under-buying for your operation.
- Full manufacturer warranty: Backed by Cast Air's warranty. We handle the process on your behalf.
- Honest upgrade guidance: If the 20HP 230V is not the right configuration for your facility, we will tell you — including whether the 460V version or a different HP class makes more sense for your situation.
Call 866-217-0063 for quick answers and help!
