Variable frequency drives, or VFDs, are used in the material handling industry to control electric hoists and other lifting equipment.
VFDs control the speed at which equipment functions, allowing operators to pre-program speeds which prevents unstable loads and possible overheating.
By reducing overheating and the swinging from unstable loads, you’re also reducing the wear and tear on your equipment. A VFD is an AC motor that increases stability and prolongs equipment life by varying the power supplied to the motor.
What types of motors did VFDs replace?
If your facilities use a crane system, you’re probably familiar with single phase or dual-phase (2 speed) motors; traditionally, these were the two options for most crane and hoist systems. While there is nothing wrong with single and dual speed motors, older systems become inefficient over time and increase the repairs and maintenance needed. You may notice that your crane is constantly wearing down or that you are always purchasing replacement parts. Inefficiency of your current hoist motor could be the cause of those breakdowns.
Both single speed and dual speed motors have disadvantages that can increase damage to your crane. For example, a 2-speed motor offers two set speeds at different ratios, a lower speed for lighter loads, and a higher speed for heavier loads. One of the the setbacks with a dual speed motor is that it doesn’t offer speed options in between those two, preset speeds. In the case of a single speed motor, the motor will operate at the same speed as fast as possible all the time, depending on the weight of the load. For instance, a single speed motor has a higher likelihood of overheating, and while a 2-speed motor offers more flexibility in operation, it doesn’t optimize the entire system to the fullest extent.
Although these types of motors are still useful and are common in older crane systems, we specialize in modernizing crane systems. VFDs are an excellent way to improve your system without a huge capital investment or overhaul of an old crane system.
A VFD is powerful technology which has revolutionized the operation of crane and hoist systems by improving the functionality of the entire crane system.
Here are 5 benefits of implementing a Variable Frequency Drive:
Greater Efficiency: VFDs generate power based on the demand of the output. Lighter loads consume less energy, greater loads consume more energy and it changes in between.
Prolonged Hoist Service Life: A variable frequency drive prevents the hoist from exerting too much power and overheating. It also only uses brakes for emergency stops, increasing brake life.
Decreased Stress on Overall System: Regular single speed or dual speed lifting involves abrupt stops to loads. The VFDs steady stops decrease damages on ends trucks, wheels, structural supports, beams and trolleys, reducing the overall repairs and maintenance needs of your entire system.
More Control Over Loads: VFD hoists decrease acceleration when needed, preventing volatile load swings, which could cause accidents.
Versatility: VFDs are sustainable options for businesses because they can be implemented into any crane and hoist system. This reduces the need to buy a new system if production increases down the road.