Castair I513HC1-S: 5HP Single-Phase Industrial Air Compressor — 80 Gallon Horizontal with Mounted Starter
The Castair I513HC1-S is a 5-horsepower, single-phase, 80-gallon horizontal industrial air compressor with a factory-mounted magnetic motor starter. This is the entry-level configuration in Castair's Industrial Series — but entry-level at Castair means a fully cast iron two-stage pump, not a cast iron-painted aluminum unit. If you are buying a shop compressor that you expect to run for 15-20 years without rebuilding the pump, this is the starting point.
The I513HC1-S uses the C1 pump (4-7.5HP rated, Inline 2 cylinder, two-stage) running at 767 RPM. The -S at the end indicates a factory-mounted magnetic motor starter is included — important if your shop requires starters for motor protection or code compliance. This is the 80-gallon horizontal version with single-phase power, making it accessible to shops that do not have 3-phase electrical service.
The -S with mounted starter distinguishes this from the base I513HC1 (which has the same compressor without the starter). If you know you need starter protection for your motor — and at 5HP single-phase, that is a reasonable requirement in many installations — this configuration saves you the trouble of sourcing and mounting one separately.
C1 Pump — Cast Iron Construction
Pump Specifications
- Pump designation: C1 — Two-stage, Inline 2 cylinder
- Rated HP range: 4-7.5HP — this pump is well within its operating range at 5HP
- Pump RPM: 767
- Flywheel: 16.875-2B
- Oil capacity: 2 quarts
- Construction: 100% cast iron cylinders, heads, valve plates, crankcase
- Bearings: Tapered roller bearings at both crankshaft ends
- Connecting rods: Precision steel with automotive-type rod insert bearings
- Valves: Disc and spring — field-replaceable
- Pistons: 4-ring for efficiency and low oil carry-over
- Unloader: Centrifugal — loadless start-up every time
Tank and Frame
- Tank capacity: 80 gallons, horizontal
- Tank construction: Powder-coated ASME-rated steel with channel saddle frame
- Safety valve: ASME-rated, factory installed
- Belt guard: Totally enclosed metal
- Discharge lines: Copper tubing or stainless braided flex line
Motor and Electrical
- Horsepower: 5HP
- Phase: Single-phase (standard shop wiring)
- Motor speed: 1725 RPM industrial
- Service factor: 15% minimum
- Motor starter: Factory-mounted magnetic motor starter (-S designation)
- Max working pressure: 175 PSI
Performance Specifications
- Motor output: 5 HP
- Electrical: Single-phase with factory-mounted magnetic starter
- Tank capacity: 80 gallons, horizontal
- Pump: C1 (Two-stage, Inline 2)
- Pump RPM: 767
- Free air delivery (0 PSI): 22.0 CFM
- Delivery at 175 PSI): 17.5 CFM
- Max pressure: 175 PSI
- Dimensions (LxWxH): 64 x 20 x 48 inches
- Weight: 600 lbs
What's in the Box
- Castair I513HC1-S compressor — fully assembled
- Factory-mounted magnetic motor starter (-S designation)
- ASME safety valve (factory installed)
- Pressure switch with unloader
- Totally enclosed metal belt guard
- Copper discharge and unloader tubing (or stainless braided flex line)
- Owner's documentation
Aftercooler is available as an option (BGAC1M — 35 CFM, for 5, 7, 10HP models). Not included in base configuration.
Available Configurations — 5HP Single-Phase Industrial Series
- I518HC1-S: 5HP, 1-phase, 80gal Horizontal, C1 pump, 767 RPM, 17.5 CFM @ 175 PSI, 64x20x48, 600 lbs — with aftercooler and mounted starter (price: ,356)
- I513HC1-S (this unit): 5HP, 1-phase, 80gal Horizontal, C1 pump, 767 RPM, 17.5 CFM @ 175 PSI, 64x20x48, 600 lbs — mounted starter, no aftercooler
- I513HC1: 5HP, 1-phase, 80gal Horizontal, C1 pump, 767 RPM, 17.5 CFM @ 175 PSI — base unit, no starter, no aftercooler
- I518HC2-S: 5HP, 1-phase, 80gal Horizontal, C2 pump, 420 RPM, 17.5 CFM @ 175 PSI, 64x20x46, 700 lbs — heavier C2 pump, slower and quieter operation (price: ,930)
- I518VC1-S: 5HP, 1-phase, 80gal Vertical, C1 pump, 767 RPM, 17.5 CFM @ 175 PSI, 32x24x74, 600 lbs — vertical tank saves floor footprint (price: ,213)
When Does a Shop Need This?
The I513HC1-S works well for:
- 1-2 technician shops running standard pneumatic tools — impact guns, ratchets, air chisels — intermittently throughout the day
- Small service bays, tire shops, or detail operations where demand is moderate and consistent
- Shops with single-phase power and no plans to upgrade to 3-phase
- Facilities that need the motor starter included but do not require an aftercooler (dry shop air applications)
Step up to the C2 pump (I518HC2-S) if:
- Noise level matters — the C2 pump at 420 RPM runs significantly quieter than the C1 at 767 RPM. If the compressor is close to the work area or in an enclosed space, the slower pump is worth the additional weight and cost.
Step up to 7.5HP if:
- You regularly run 2-3 tools simultaneously and find the 5HP system pressure dropping during peak demand — the 7.5HP series delivers 24.8-28.1 CFM at 175 PSI
Why Buy From Air Compressor Factory Direct?
Since 2016, we have sold industrial air compressors and shop equipment to working shops across the country. The difference between a Castair C1 pump compressor and a big-box store unit is not marketing — it is cast iron versus aluminum, tapered roller bearings versus ball bearings, and slow-speed operation versus high-RPM wear. We explain those differences because they matter to your 10-year maintenance cost, not just your purchase price.
- Free shipping to commercial addresses in the lower 48 states
- Free tech support at 866-217-0063
- Full Castair manufacturer warranty
- Honest buying guidance — we will tell you if the 7.5HP better fits your load
- Authorized dealer with direct Castair factory support
Call 866-217-0063 for quick answers and help!
