Variable Frequency Drive Electric Compressors
VFD Series
25-450 HP
Expertly engineered to save energy and cut consumption costs, the Variable Frequency Drive (VFD) Series compressors supply the exact amount of air each shift requires. No more, no less.
The VFD’s are some of the many industrial electric compressed air solutions offered by Sullivan-Palatek.
Distributor pricing by quote. Equipment pricing and availability are confirmed through authorized distributors. Request pricing
Built for dependable performance
Features & Benefits
- Wide power range for 230V and 460V
- TEFC Motor
- Pressure transducer motor speed control
- Factory Settings:
- Programmable digital outputs
- Digital inputs
- Programmable outputs: four relays, four transistors
- Eight programmable parameter sets with S-curves, power off function, PID process controller, electronic motor protection, internal timer. Output frequencies up to 160 Hz with output voltage stabilization; switching frequencies up to 16kHz; output phase monitoring.
- DC bus circuit connection, moto thermal sensor connection, hardware current line
- The VFD helps reduce energy. Operating at 70% capacity, the VFD consumes 10% less power than a standard compressor operating with on-off control and 20% less than a compressor with modulating control.
- The VFD has a soft start feature that maintains a low starting current. It reduces stress on the site power supply and also reduces motor wear.
- The VFD system complies with the Electro-Magnetic Compatibility standard and is UL/CSA listed.
- The VFD system is not limited to a fixed number of starts per hour.
- VFD 50HP and up have dedicated fan and motor drives to improve cooling and improve compressor efficiencies
Model data
Technical Specifications
| Model | Horsepower (hp) | Capacity (cfm) at 100 Pressure (psi) | Capacity (cfm) at 125 Pressure (psi) | Capacity (cfm) at 150 Pressure (psi) | Capacity (cfm) at 175 Pressure (psi) |
|---|---|---|---|---|---|
| SP11-25VFD | 25 | *117.2 | *105.9 | *90.1 | 80.6 |
| SP11-30VFD | 30 | *151.1 | *129.3 | *111.5 | 102.4 |
| SP11-40VFD | 40 | *185.3 | *162.7 | *147.2 | 125.6 |
| SP13-40VFD | 40 | *190.9 | *167.2 | *147.7 | 136.8 |
| SP13-50VFD | 50 | *236.3 | *220.3 | *197.2 | 176.4 |
| SP13-60VFD | 60 | *270 | *260.8 | *233 | 215.4 |
| SP16-75VFD | 75 | 346.2 | - | - | - |
| SP16-100VFD | 100 | - | *440 | - | - |
| SP20+125VFD | 125 | 648.7 | 568.5 | 513.9 | - |
| SP20+150VFD | 150 | 759.8 | 705.1 | 633.4 | - |
| SP20+200VFD | 200 | *1014.5 | *938.3 | *847.3 | *768.9 |
| SP25-250VFD | 250 | 1267.7 | *1129.1 | *1029.6 | *914.5 |
| SP25-300VFD | 300 | 1391.3 | 1264.6 | *1118.8 | *1021.2 |
| SP25-350VFD | 350 | 1535.6 | 1380.1 | 1263.1 | *1118.2 |
| SP32-300VFD | 300 | 1490 | - | - | - |
| SP32-350VFD | 350 | 1650 | 1488 | - | - |
| SP32-400VFD | 400 | 1790 | 1633 | - | - |
Applications
- All Industrial facilities
- Infrastructure
- Power generation
- Pump and pulp
- Cement work
- Amusement parks
- Food packaging
- Pharmaceutical
- Body shops
Downloads
VARIABLE-SPEED COMPRESSOR APPLICATION GUIDE
WHEN SHOULD A PLANT CHOOSE A VFD ROTARY SCREW COMPRESSOR?
Variable-frequency-drive (VFD) air compressors adjust motor speed to follow changing compressed air demand. The right choice depends on the plant load profile, required pressure and operating conditions, not on a universal energy-savings percentage.
WHEN VFD CONTROL FITS
Consider variable speed when measured air demand changes significantly across production shifts, machines cycle on and off, or the system must follow changing demand while maintaining a controlled pressure band. Confirm that proposed operating points remain within the specific model's approved speed and airflow range.
WHEN FIXED SPEED MAY FIT
A fixed-speed rotary screw compressor can be appropriate when continuous production has a relatively steady load. Compare total power consumption and control behavior for the entire system, including standby and unloaded running, instead of selecting a drive type solely from advertised peak efficiency.
HOW TO VERIFY THE COMPARISON
Provide the same delivered CFM and discharge PSI in competing proposals. Compare applicable CAGI or manufacturer test data, input power, controls, service requirements and the actual demand profile. Where practical, use short-interval load and power measurements to evaluate projected savings.
VFD COMPRESSOR QUOTE INPUTS
- Typical and peak airflow, along with the hours spent at part load
- Required PSI at the production equipment and the acceptable system pressure band
- Site voltage, electrical constraints, ambient temperature and ventilation
- Current equipment control mode, receiver capacity and air-leak findings
VARIABLE-SPEED ROTARY SCREW / PUBLISHED MODEL COMPARISON
VFD Series: Match the Model, Pressure and Plant Demand
The VFD Series brings together published variable-frequency-drive rotary screw compressor configurations across multiple Sullivan-Palatek families. Begin with actual demand over time, select a model that has a documented rating at the required pressure, and use the individual family pages and CAGI data for the final engineering comparison.
Use the Published VFD Model Matrix
The existing Specifications table lists specific VFD model variants from SP11 and SP13 through higher-horsepower SP25 and SP32 units. Individual model/pressure cells may be blank; they must not be interpreted as available ratings. For example, the displayed SP25 VFD rows are 250-350 HP, and the displayed SP32 VFD rows are 300-400 HP. Confirm the exact current drive/package offering before specifying equipment.
Plan Pressure Control and Multiple Compressors
Evaluate how production shifts, standby equipment and storage affect the desired pressure band. A VFD compressor can be considered for variable demand, while fixed-speed equipment may serve steady base loads. Review controller compatibility and lead-lag sequencing against the selected models, not a generic claim that one configuration is best for every plant.
Verify Drive Installation and Air-System Integration
Confirm motor voltage, current drive compatibility, equipment-room ventilation and available controller options for the exact package. VFD speed control does not replace correctly sized receiver storage, dryers, filtration or condensate handling. Evaluate piping pressure loss and air-quality requirements alongside compressor modulation to plan a stable complete system.
Questions to Answer Before Choosing
Does the VFD Series cover every compressor horsepower at every pressure?
No. The published VFD model table lists selected configurations and pressure ratings. A missing cell or missing model is not confirmation of a supported operating point. Review the individual compressor family and current CAGI/manufacturer documentation before selecting a VFD model.
How do I compare SP25 and SP32 variable-speed compressor options?
The VFD table includes SP25-250/300/350VFD and SP32-300/350/400VFD rows, each with its own published pressure-dependent capacities. Compare matching PSI values, expected load profile, drive compatibility and installed equipment; consult current data sheets for final confirmation.
Can a VFD air compressor replace receiver storage or a refrigerated dryer?
No. Variable-speed control adjusts compressor output to follow demand; it does not perform air drying or filtration, and it does not automatically eliminate storage needs. Select receiver volume and air treatment from the actual load profile, pressure stability goals, water removal requirements and approved equipment guidance.
Planning tools / Sullivan-Palatek
See How a Complete Air System Comes Together
A compressor is one part of a dependable air system. Explore the flow of air through storage, dryers, filtration, drains, and condensate treatment, then build a preliminary system for our team to review.
Explore the Interactive System
Explore available compressor models and equipment in the interactive 3D experience. View components and discover how they fit into a compressed-air system.
Explore the interactive systemBuild a System & Request a Quote
Enter your approximate CFM, pressure and air-quality needs. Review a conceptual configuration, then send your system to Sullivan-Palatek for a formal sales review.
Build a system and request a quoteConcept layouts are for planning, not a final engineering design or binding quotation. Equipment selection, pricing, availability and installation requirements are confirmed by our sales and engineering teams. Serving an Indianapolis-area facility? Explore regional compressor assistance.
Application to equipment
Continue Your Compressed-Air Research
Connect this information with relevant applications, published equipment and technical references. Final equipment selection requires an application-specific review.
Related industry applications
Supporting technical reading
Verify specifications and treatment
Explore specific uses
Applications for This Equipment or Industry
Follow these practical guides to compare tasks, demand patterns, air treatment and application-specific specifications.