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𝗙𝗥𝗘𝗘 𝗦𝗛𝗜𝗣𝗣𝗜𝗡𝗚 𝗜𝗡 𝗟𝗢𝗪𝗘𝗥 𝟰𝟴 𝗦𝗧𝗔𝗧𝗘𝗦 & 𝗡𝗢 𝗦𝗔𝗟𝗘𝗦 𝗧𝗔𝗫
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7.5 HP 1-Phase Motor for Air Compressor | 208-230V | 1750 RPM | 1-3/8-Inch Keyed Shaft | Castair

Original price $1,321.00 - Original price $1,321.00
Original price
$1,321.00
$1,321.00 - $1,321.00
Current price $1,321.00
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What Sets Us Apart
12-Month Warranty (Industry-Leading Coverage)
Free Shipping (Lower 48 US States)
• Comes with hoses, fittings, and couplers (Jobsite ready)
  • 1750 RPM Operating Speed
  • Single Phase Design
  • 208-230V Dual Voltage
  • 184T Frame Construction
  • 1.25 Service Factor
  • TEFC Enclosure Protection
  • Explosion Proof Certified
  • Precision Keyed Shafts
  • UL CSA Listed
  • Industrial Grade Construction
Overview

This 7.5 HP single-phase motor delivers reliable power for stationary air compressor systems operating on standard 208-230V electrical supply. When your workshop air compressor needs a replacement motor or you're building a custom compressed air system, consistent power output determines whether your pneumatic tools perform reliably or leave you waiting for pressure to rebuild.

The Castair GWG311292 motor operates at 1750 RPM with precise speed control that maintains consistent airflow generation across varying load conditions. Single-phase design eliminates the need for three-phase electrical infrastructure while delivering the torque characteristics required for positive displacement air compressor applications.

A 1-3/8-inch keyed shaft provides secure mechanical coupling with standard air compressor pump assemblies. The keyed shaft design prevents slippage under load and eliminates the belt tension issues that cause premature wear in pulley-driven systems. Direct drive compatibility reduces maintenance intervals and improves power transfer efficiency.

At 145 pounds, this motor provides the thermal mass and structural stability needed for continuous-duty air compressor operation. Heavy construction absorbs vibration and heat cycling that lighter motors cannot handle during extended run times. The weight distribution helps maintain proper alignment between motor and pump assemblies.

Standard 208-230V single-phase electrical requirements make this motor compatible with existing workshop electrical systems without requiring electrical service upgrades. Most commercial and industrial facilities already supply this voltage through standard electrical panels, eliminating installation complexity and reducing setup costs.

Specifications

Technical specifications define the exact electrical and mechanical parameters for proper air compressor integration.

Electrical Specifications

Power output measures 7.5 horsepower at rated voltage and frequency. Single-phase design operates on 208-230V electrical supply with standard 60 Hz frequency requirements. Motor draws approximately 34 amperes at full load with power factor correction built into the design.

Mechanical Specifications

Operating speed maintains 1750 RPM under full load conditions. The 1-3/8-inch diameter shaft features a standard keyway for positive mechanical connection with air compressor pump assemblies. Overall motor weight totals 145 pounds with NEMA frame construction.

Environmental Ratings

Operating temperature range spans -10°F to 104°F for reliable performance in unheated workshop environments. Insulation class protects windings against moisture and temperature cycling. Enclosure design prevents dust and debris infiltration during normal operation.

Features

Design features address the specific requirements of air compressor drive applications where consistent torque and thermal management determine system reliability.

Single-Phase Power Design

Single-phase electrical operation eliminates three-phase infrastructure requirements while maintaining sufficient starting torque for air compressor loads. Built-in starting capacitor provides the phase shift needed for reliable startup under pressure.

Keyed Shaft Construction

The 1-3/8-inch keyed shaft creates positive mechanical connection with air compressor pump assemblies. Standard keyway dimensions match common air compressor pump shaft requirements. Shaft material resists wear and maintains dimensional accuracy under continuous operation.

Thermal Protection System

Integrated thermal overload protection monitors winding temperature and prevents damage from overheating. Automatic reset functionality restores operation once safe operating temperature returns. Protection system responds to both electrical overload and ambient temperature conditions.

Benefits

Operational benefits focus on maintaining consistent air pressure and reducing system downtime in workshop and industrial compressed air applications.

Consistent Air Pressure Generation

Precise 1750 RPM speed control maintains steady air compressor pump operation across varying electrical supply conditions. Consistent pump speed translates directly to predictable air pressure recovery times and stable system pressure maintenance.

Direct Drive Compatibility

The 1-3/8-inch keyed shaft enables direct coupling with air compressor pumps without belt drive complexity. Direct drive systems eliminate belt stretching, slippage, and periodic tension adjustments that increase maintenance requirements and reduce efficiency.

Standard Electrical Integration

Single-phase 208-230V requirements match existing electrical infrastructure in most workshop and industrial facilities. Standard voltage compatibility eliminates electrical service upgrades and reduces installation complexity for replacement motor applications.

Additional Information

Installation and compatibility information ensures proper motor selection and system integration for specific air compressor applications and electrical supply conditions.

Electrical Supply Requirements

Motor operates on 208-230V single-phase electrical supply with 60 Hz frequency. Full load amperage draws approximately 34 amperes requiring appropriate circuit protection and conductor sizing. Starting current peaks at approximately 180 amperes during motor startup.

Mounting and Alignment

Standard NEMA frame construction provides universal mounting compatibility with air compressor base assemblies. Motor feet align with standard bolt patterns used in stationary air compressor systems. Proper shaft alignment prevents premature bearing wear and vibration issues.

Maintenance Requirements

Bearing lubrication intervals occur every 2000 operating hours under normal conditions. Thermal protection system requires no adjustment but should be tested annually. Electrical connections need inspection every 6 months to prevent overheating from loose terminals.

Warranty Info

Warranty coverage protects against manufacturing defects in materials and workmanship for one full year from purchase date. Coverage includes motor windings, bearings, and shaft assembly under normal operating conditions within specified electrical and environmental parameters.

Warranty service requires installation by qualified electrical personnel following NEC requirements. Proper electrical protection, grounding, and ventilation must be maintained throughout the warranty period. Coverage excludes damage from electrical supply issues, contamination, or operation outside specified parameters.

Claims processing requires motor model number, purchase date documentation, and failure description with operating conditions. Replacement motors ship within 5 business days of claim approval. Installation labor and shipping costs remain customer responsibility under warranty terms.

What CFM and PSI does this compressor deliver?

This is a motor for air compressors, not a complete compressor system. The CFM and PSI output depends on the compressor pump you pair with this motor. The 5 HP motor can typically drive pumps producing 15-20 CFM at 175 PSI, while the 7.5 HP motor can power pumps delivering 25-30 CFM at similar pressures. The 1750 RPM speed provides optimal compatibility with most two-stage and single-stage compressor pumps. Your actual air output will depend on pump displacement, cylinder configuration, and system efficiency. Professional contractors often choose the 7.5 HP motor for higher air demands from pneumatic tools, spray equipment, and material handling systems. The robust construction ensures consistent performance under demanding compressed air applications. Forge Claw offers multiple financing options for qualified buyers.

What air tools can I run with this compressor?

The air tools you can run depend on the compressor pump paired with this motor. With a properly sized pump, the 5 HP motor typically supports impact wrenches, nail guns, spray guns, sanders, and small pneumatic cylinders for intermittent use. The 7.5 HP motor can handle continuous operation of larger tools like die grinders, air hammers, sandblasters, and multiple tools simultaneously. Both motors provide the power foundation for systems running paint sprayers, tire inflation equipment, and pneumatic material handling systems. The single phase design works well in shops and job sites with standard electrical service. The 1.25 service factor allows temporary overload during high-demand periods without motor damage. Professional contractors rely on these motors for consistent compressed air delivery that keeps pneumatic tools operating efficiently without pressure drops during critical work phases.

Is this compressor portable enough for job sites?

This is a motor component for building or rebuilding stationary compressor systems, not a portable compressor unit. The 5 HP motor weighs 13.9 pounds and could work in smaller mobile compressor builds, while the 7.5 HP motor at 145 pounds is designed for permanent installations. Most contractors use these motors for shop-based compressor systems or permanent job site installations rather than portable equipment. The single phase power requirement means you can operate in locations with standard 230V electrical service without three-phase converters. The robust 184T frame construction handles the mounting requirements for stationary compressor bases and tank systems. For true portability, you would need to build a complete compressor system on wheels or a trailer. These motors excel in fixed installations where reliable, continuous compressed air is needed for shop operations or permanent job site pneumatic systems.

What maintenance does this compressor require?

As a motor component, maintenance focuses on electrical connections, bearing lubrication, and cooling system cleanliness. Check electrical connections quarterly for tightness and signs of overheating. The TEFC enclosure requires periodic cleaning of cooling fan and housing fins to prevent overheating from dust buildup. Bearings typically need re-greasing annually under normal operating conditions, more frequently in dusty environments. Monitor motor current draw to detect bearing wear or pump problems early. The explosion proof certification requires maintaining proper enclosure sealing for safety compliance. Check mounting bolts for tightness during regular inspections. The open drip proof design protects against most environmental conditions but requires shelter from direct weather exposure. Most maintenance issues stem from electrical problems rather than mechanical wear. Professional installation ensures proper electrical sizing and safety disconnects. The UL and CSA listings provide guidance for safe operating parameters and maintenance intervals.

How does tank size affect how long I can run tools continuously?

Tank size determines air storage capacity but this motor's performance affects how quickly you can refill that storage. Larger tanks provide longer runtime between compressor cycles, reducing motor start-stop frequency and extending motor life. A 60-gallon tank with the 5 HP motor typically supports intermittent tool use, while 80-120 gallon tanks work better with the 7.5 HP motor for continuous operations. The motor's ability to drive the compressor pump efficiently affects recovery time after tank pressure drops. Higher CFM pumps paired with these motors refill tanks faster, reducing wait times between high-demand tool usage. The 1750 RPM speed optimizes pump efficiency for sustained air production. Tank size also affects thermal management - larger tanks mean longer cooling periods between compression cycles. Professional applications often use 120+ gallon tanks with the 7.5 HP motor for continuous spray finishing, sandblasting, or multiple tool operation without pressure drops affecting work quality.

Overview

This 7.5 HP single-phase motor delivers reliable power for stationary air compressor systems operating on standard 208-230V electrical supply. When your workshop air compressor needs a replacement motor or you're building a custom compressed air system, consistent power output determines whether your pneumatic tools perform reliably or leave you waiting for pressure to rebuild.

The Castair GWG311292 motor operates at 1750 RPM with precise speed control that maintains consistent airflow generation across varying load conditions. Single-phase design eliminates the need for three-phase electrical infrastructure while delivering the torque characteristics required for positive displacement air compressor applications.

A 1-3/8-inch keyed shaft provides secure mechanical coupling with standard air compressor pump assemblies. The keyed shaft design prevents slippage under load and eliminates the belt tension issues that cause premature wear in pulley-driven systems. Direct drive compatibility reduces maintenance intervals and improves power transfer efficiency.

At 145 pounds, this motor provides the thermal mass and structural stability needed for continuous-duty air compressor operation. Heavy construction absorbs vibration and heat cycling that lighter motors cannot handle during extended run times. The weight distribution helps maintain proper alignment between motor and pump assemblies.

Standard 208-230V single-phase electrical requirements make this motor compatible with existing workshop electrical systems without requiring electrical service upgrades. Most commercial and industrial facilities already supply this voltage through standard electrical panels, eliminating installation complexity and reducing setup costs.

Specifications

Technical specifications define the exact electrical and mechanical parameters for proper air compressor integration.

Electrical Specifications

Power output measures 7.5 horsepower at rated voltage and frequency. Single-phase design operates on 208-230V electrical supply with standard 60 Hz frequency requirements. Motor draws approximately 34 amperes at full load with power factor correction built into the design.

Mechanical Specifications

Operating speed maintains 1750 RPM under full load conditions. The 1-3/8-inch diameter shaft features a standard keyway for positive mechanical connection with air compressor pump assemblies. Overall motor weight totals 145 pounds with NEMA frame construction.

Environmental Ratings

Operating temperature range spans -10°F to 104°F for reliable performance in unheated workshop environments. Insulation class protects windings against moisture and temperature cycling. Enclosure design prevents dust and debris infiltration during normal operation.

Features

Design features address the specific requirements of air compressor drive applications where consistent torque and thermal management determine system reliability.

Single-Phase Power Design

Single-phase electrical operation eliminates three-phase infrastructure requirements while maintaining sufficient starting torque for air compressor loads. Built-in starting capacitor provides the phase shift needed for reliable startup under pressure.

Keyed Shaft Construction

The 1-3/8-inch keyed shaft creates positive mechanical connection with air compressor pump assemblies. Standard keyway dimensions match common air compressor pump shaft requirements. Shaft material resists wear and maintains dimensional accuracy under continuous operation.

Thermal Protection System

Integrated thermal overload protection monitors winding temperature and prevents damage from overheating. Automatic reset functionality restores operation once safe operating temperature returns. Protection system responds to both electrical overload and ambient temperature conditions.

Benefits

Operational benefits focus on maintaining consistent air pressure and reducing system downtime in workshop and industrial compressed air applications.

Consistent Air Pressure Generation

Precise 1750 RPM speed control maintains steady air compressor pump operation across varying electrical supply conditions. Consistent pump speed translates directly to predictable air pressure recovery times and stable system pressure maintenance.

Direct Drive Compatibility

The 1-3/8-inch keyed shaft enables direct coupling with air compressor pumps without belt drive complexity. Direct drive systems eliminate belt stretching, slippage, and periodic tension adjustments that increase maintenance requirements and reduce efficiency.

Standard Electrical Integration

Single-phase 208-230V requirements match existing electrical infrastructure in most workshop and industrial facilities. Standard voltage compatibility eliminates electrical service upgrades and reduces installation complexity for replacement motor applications.

Additional Information

Installation and compatibility information ensures proper motor selection and system integration for specific air compressor applications and electrical supply conditions.

Electrical Supply Requirements

Motor operates on 208-230V single-phase electrical supply with 60 Hz frequency. Full load amperage draws approximately 34 amperes requiring appropriate circuit protection and conductor sizing. Starting current peaks at approximately 180 amperes during motor startup.

Mounting and Alignment

Standard NEMA frame construction provides universal mounting compatibility with air compressor base assemblies. Motor feet align with standard bolt patterns used in stationary air compressor systems. Proper shaft alignment prevents premature bearing wear and vibration issues.

Maintenance Requirements

Bearing lubrication intervals occur every 2000 operating hours under normal conditions. Thermal protection system requires no adjustment but should be tested annually. Electrical connections need inspection every 6 months to prevent overheating from loose terminals.

Warranty Info

Warranty coverage protects against manufacturing defects in materials and workmanship for one full year from purchase date. Coverage includes motor windings, bearings, and shaft assembly under normal operating conditions within specified electrical and environmental parameters.

Warranty service requires installation by qualified electrical personnel following NEC requirements. Proper electrical protection, grounding, and ventilation must be maintained throughout the warranty period. Coverage excludes damage from electrical supply issues, contamination, or operation outside specified parameters.

Claims processing requires motor model number, purchase date documentation, and failure description with operating conditions. Replacement motors ship within 5 business days of claim approval. Installation labor and shipping costs remain customer responsibility under warranty terms.