Variable Frequency Drives for AC Electric Motors
Variable Frequency Drives (VFDs) are essential for controlling AC electric motors. By adjusting the motor's frequency (or hertz) and voltage, a VFD provides precise motor speed control. VFDs offer several major advantages: significant energy savings by reducing power consumption during partial load operation, increased production through precise speed control, reduced production costs with optimized motor performance, extended equipment life by minimizing stress on motors, and reduced maintenance costs due to lower wear and tear.
Our affordable adjustable speed drives are the ideal solution for crane control upgrades, overhead crane modernizations, hoist control, bridge crane control, and trolley control. Whether you are operating a simple hoist or a complex automated system, our VFDs provide the precision and reliability you need.
Our service technicians have completed numerous VFD modernizations across the region — replacing aging contactor-based controls with Magnetek VFD systems that deliver smoother motion, improved spotting accuracy, and simplified wiring. See our crane VFD controls upgrade case study and Magnetek G+ Mini VFD upgrade case study for real-world examples.
IMPULSE•G+ Mini
The IMPULSE•G+ Mini VFD is the #1 solution for low horsepower AC motors in the material handling industry, covering 1/4 HP through 20 HP in both 230 VAC and 460 VAC configurations. As the most compact and cost-effective Magnetek crane VFD, the G+ Mini is ideal for small hoist control, jib crane traverse drives, and auxiliary motions where a full-size Series 4 or Series 5 drive would be oversized. If you’re looking for a miniature VFD or a variable frequency drive for a small AC motor, the G+ Mini delivers proven Magnetek reliability in the most space-efficient package available.
G+ Mini
IMPULSE•G+ and VG+ Series 4
For Class C, D, E and F cranes the G+ and VG+ Series 4 adjustable frequency crane controls are the ideal choice. These variable speed drives have power modules which can withstand four times more thermal cycles than any other overhead material handling VFD's. We are so confident in the durability, safety and reliability of the IMPULSE•G+ and VG+ Series 4 drives they are backed by an industry-leading three-year manufacturers' warranty.
G+ Series 4 VFD, 230 VAC
G+ Series 4 VFD, 460 VAC
G+ Series 4 VFD, 575 VAC
VG+ Series 4 VFD, 230 VAC
VG+ Series 4 VFD, 460 VAC
VG+ Series 4 VFD, 575 VAC
IMPULSE•G+ and VG+ Series 5
The Magnetek IMPULSE•G+ and VG+ Series 5 Variable Frequency Drives are the latest generation of crane-specific VFD technology, engineered specifically for overhead crane and hoist applications from 0.75 HP to 500 HP. Unlike general-purpose drives, Series 5 VFDs include a comprehensive suite of built-in crane safety features — including Safe Torque Off rated to SIL3, load check, torque proving, anti-shock, brake integrity testing, and built-in LaserGuard™ collision avoidance support — all as standard, without additional hardware or external controllers.
Both models cover CMAA Class A through F service and are rated for ambient operating temperatures from 14° to 140°F (-10° to 60°C). Series 5 VFDs also feature a built-in USB port for low-voltage commissioning (24 VDC only — no PPE required), date and time-stamped fault logs, and compatibility with Intelli-Connect™ Mobile for wireless monitoring and diagnostics. Models 30 HP and above offer a smaller footprint than Series 4 — up to 45% smaller on larger frame sizes — and terminal boards no longer carry internal memory, making replacements plug-and-play. All Series 5 drives are backed by Magnetek’s industry-leading three-year warranty.
IMPULSE•G+ Series 5 — V/Hz Control
The G+ Series 5 is the right choice for hoist applications using worm gear and mechanical load brake designs, as well as standard traverse motions. It operates in open-loop V/Hz control and covers the full range of CMAA Class A–F service. The G+ is the most cost-effective Series 5 option for straightforward crane control upgrades and new installations where encoder feedback is not required.
IMPULSE•VG+ Series 5 — Vector Control
The VG+ Series 5 adds closed-loop vector control with encoder feedback, enabling a 1500:1 speed control range versus 40:1 on the G+. It includes additional safety features including torque proving, anti-shock, snapped shaft detection, slack cable detection, and motor rollback detection — features required for non-mechanical load brake hoists and demanding Class E–F duty applications. The VG+ also supports drive synchronization, weight measurement and load summing, and static stepless simulation for traverse motions.
G+ Series 5 VFD, 230 VAC
G+ Series 5 VFD, 460 VAC
VG+ Series 5 VFD, 230 VAC
VG+ Series 5 VFD, 460 VAC
Variable Frequency Drive Documents
Variable Frequency Drive FAQ
What is a crane VFD and how does it work?
A crane VFD (Variable Frequency Drive) controls the speed of an AC electric motor by adjusting the output frequency and voltage supplied to the motor. For overhead crane and hoist applications, this means smooth acceleration and deceleration, precise load spotting, and soft starts that reduce mechanical stress on the drive train. Unlike contactor-based controls that switch between fixed speeds, a VFD gives operators infinitely variable speed control throughout the full range of motion.
What is the difference between the G+ and VG+ Series 5?
The IMPULSE•G+ Series 5 uses open-loop V/Hz control and is designed for worm gear and mechanical load brake hoists and standard traverse motions. The IMPULSE•VG+ Series 5 adds closed-loop vector control with encoder feedback, enabling a 1500:1 speed control range, torque proving, anti-shock, snapped shaft detection, slack cable detection, and drive synchronization for multi-hoist applications. For most new crane installations and modernizations, the G+ covers standard duty applications while the VG+ is specified for non-mechanical load brake hoists and Class E–F heavy-duty service.
Can I run a 50 Hz motor on a 60 Hz VFD?
Yes — this is one of the practical advantages of a variable frequency drive. A VFD can supply any output frequency regardless of input line frequency, so a motor rated for 50 Hz can be operated at 60 Hz output. However, running a 50 Hz motor above its rated frequency will increase speed proportionally while reducing available torque. For crane and hoist applications, you should consult with a qualified engineer to verify the motor’s thermal capacity and mechanical rating before operating above nameplate frequency. The IMPULSE Series 5 VFDs include motor auto-tuning and thermal protection features to help manage this safely.
Can Series 4 option cards be used in Series 5 VFDs?
Yes. All option cards from the G+ and VG+ Series 4 are fully compatible with Series 5 VFDs. Series 5 terminal boards no longer carry internal memory, making them plug-and-play replacements. For models 30 HP and above, Series 5 VFDs have a smaller physical footprint than Series 4 — mounting adapter plates are available for 230 VAC models 2003–2047 and 460 VAC models 4001–4031 so that new mounting holes do not need to be drilled.
TSOC distributes variable frequency drives (VFD); serving clients from coast to coast, Canada, Mexico, and especially focused in Missouri, Illinois, Indiana, Iowa, Kansas, Nebraska, Arkansas, Mississippi, Tennessee, Kentucky, South Carolina, Florida, and Oklahoma.