Also known as frequency-controlled hoists, an inverter hoist uses variable frequency drives (or VFDs) to drive its electric motor. By definition, a VFD is an AC-motor controller that controls the variation in voltage and frequency supplied to the electric motor. Besides hoists, VFDs are commonly used in overhead cranes and lifting equipment. Why are VFDs commonly used in electric hoists used for material handling and overhead lifting? Let us look at 5 of its advantages.
5 Advantages of an Inverter Hoist
Here is how the VFD controller is beneficial in controlling your inverter hoist:
Multiple speeds: With a VFD, you can operate your hoist at different speeds, thus enabling you to customise hoist controls depending on the application.
Better load control: Whether it is for slowing down or accelerating the load, VFDs offer better control than single-speed hoists which have more load swings and shocks. VFDs can also prevent load swings even in traverse motions.
Energy efficiency: Slowing down and lowering the hoist using VFDs produces regenerative energy converted into heat with a braking resistor. This can be smoothly returned to the source, thus saving energy, and improving efficiency. Additionally, VFDs also reduce energy consumption by only consuming power when required.
Longer hoist life:Hoists using VFDs safeguard the hoist motor through thermal overload and protection from overcurrent. VFDs also use the “ramp-down-to-stop” mode of hoist braking which reduces physical wear of brake components. Each of these functionalities can increase the overall life of your hoist.
Digital diagnostics: VFD-powered hoists are easier to troubleshoot because it can show the relevant error codes at the time of malfunction.
Inverter hoists are also easy to maintain because it can record operation history. We can accurately predict the replacement cycle of spare parts.
Additional features
In Kito, our VFD-controlled hoists offer a range of features for enhanced safety and performance. For instance, inverter hoists can detect lighter load conditions and activate its “No-load High-speed” function to switch to high-speed operation automatically.
As compared to pole change motors, the dual-speed inverter motor delivers a smoother start and stop movement – thus reducing load swings. With its high-to-low speed ratio set to 6:1, inverter hoists have improved low-speed stops and better positioning accuracy. On average, a no-load operation is 1.3x faster than a full-load operation.
Inverter is fitted with the efficient ER2/EQ/MR2 inverter unit customised to handle lifting and traversing loads with optimum control. Its built-in software is equipped to ensure safety measures against any major impact and heat conditions.
Additionally, our EQ hoists have an Electronic Overload Limiter which can automatically detect any overload condition and stop the hoist from lifting them.