SKF has launched a unique solution, the SKF Electrical Discharge Detector (EDD) Pen TKED. It is a handheld instrument innovated by SKF (patent pending) that detects the number of electrical discharges in electrical motor bearings.

Since the 1990s, the use of variable-frequency drives (VFDs) to control
alternating-current (AC) motors has become very common, as such drives can save energy. However, the drawback to using VFDs is that electrical motors are more vulnerable to electrical erosion in the bearings.

As soon as a motor starts, the VFD induces motor shaft voltages that increase until they find discharge paths to the earth via the motor frame. Often the motor bearings present the path of least resistance. When the voltage reaches a level to overcome the lubricant film layer in the bearing, the shaft current discharge occurs. Over time this causes electrical erosion, which in turn can cause bearings to fail prematurely, causing motor failure and unplanned downtime.

Until now there hasn’t been an easy, cost-effective method to detect electrical discharge currents in electric motor bearings. But now, thanks to the EDD Pen, it is possible. And because the EDD Pen is operated remotely, using only two buttons, it is both easy and safe to use.

Unlike other traditional methods, you can detect the electrical discharge currents directly rather than measuring the effects in later stages, after damage has occurred.

When incorporated into a predictive maintenance programme, the EDD Pen can prevent significant unplanned machine downtime.