Since their invention in the 1980s, variable frequency drives (VFD) have been heavily used in industrial motors to control the frequency and voltage of power supplied to motors. This is important for several reasons. It helps save on electrical costs, it improves system efficiency, and it reduces the stress on machines, thereby extending their lifespans. Modern VFDs may also come with diagnostic capabilities or features that can improve the productivity of the motor.
But, VFDs have their downsides as well. Most notably, VFDs are susceptible to electrical arcing, which can cause substantial damage to equipment.
Why does electrical arcing happen? According to ceramic bearing manufacturer CBR Bearing, “Electrical arcing occurs when the voltage gets too high and causes an ongoing electric discharge, which can damage your equipment and eventually cause it to fail.”
When it comes to bearings, electrical arcing is especially damaging. When the voltage produced exceeds what a traditional steel bearing’s lubrication can absorb, small pieces of the steel balls in the ball bearings can break off, which can eventually cause the bearing to fail. When a bearing fails, the machine shaft often fails, and then the machine itself can break down. When a machine fails, production comes to a halt until it can be repaired.
The best way to prevent this type of failure is to eliminate the possibility of electrical arcing. This doesn’t mean forgoing the use of a VFD, thereby eliminating the benefits associated with them. Electrical arcing can be prevented simply by switching up the types of bearings that are used in motors.
According to experts, opting for ceramic hybrid bearings instead of traditional steel bearings eliminates electrical arcing in motors with VFDs. If a motor currently has steel bearings, they can be replaced with ceramic hybrid bearings of the same size. Ceramic hybrid bearings have silicon nitride balls (rather than steel balls), which are electrically non-conductive.
In addition to preventing electrical arcing and the damage it can cause, ceramic hybrid bearings are also more durable and more efficient than their steel counterparts, making them a great investment. In fact, quality ceramic hybrid bearings can last up to ten times longer than steel bearings. While it’s true that ceramic hybrid bearings cost more upfront than steel bearings, they are definitely worth the price when all of the factors are considered.
If you’ve looked into ceramic hybrid bearings before and were scared away by the high prices and long lead times, you may want to take another look at them. The prices have come down considerably over the years, and bearing manufacturers that specialize in ceramic hybrid bearings often have many sizes in stock and ready to ship out the same day.
As a business owner, investing in your equipment is one of the best things you can do for your bottom line, and investing in quality bearings that will help prevent equipment damage is a great place to start.