Premature bearing failure is a major cause of motor downtime and costly repairs. Helwig Carbon uses proven silver graphite brush technology in a variety of bearing protection kits for motor shaft grounding. Our kits effectively divert induced electrical currents away from the bearings, protecting them from damage and failure. What’s more, our bearing protection kits are economical, easy to install, and offer the industry’s best shaft grounding performance.
Variable frequency drives (VFD) used on AC and DC motors produce induced electrical currents on the motor shaft. This current seeks the path of least resistance to ground which is typically through the motor bearings. When the current passes through the bearings electrical arcs take place leading to fluting, pitting, and bearing damage. The fluted or damaged bearing surface causes noise, vibration, and premature bearing failure.
Effective shaft grounding and bearing protection from Helwig Carbon will divert the current from the motor shaft and provide the lowest resistance path to ground in an economical product. The result is the lowest shaft voltage and maximum discharge to ground through the kit rather than through the bearings or other components.
Major OEMs choose Helwig Carbon’s solution as their preferred method to protect motor bearings. Unlike other options, this carbon brush technology uses a proprietary silver graphite material that provides superior voltage minimization. Advantages include:
Helwig Carbon’s shaft grounding minimizes shaft voltage and electrical noise. This graph shows induced shaft voltage with the Helwig BPK-4 vs. a carbon fiber ring. Lower value equals more effective bearing protection. Peak-to-peak voltage for Helwig’s solution is more than 5 times lower than the carbon fiber ring, which significantly reduces the risk of current flowing through the bearing.
These results illustrate that a Helwig BPK effectively ensures against the risk of bearing damage, therefore improving the life of the motor.
Helwig Carbon bearing protection kits (BPK) fit a variety of motor shafts, offer several mounting options, and are easy to install and maintain. BPK will deliver many years of superior performance in shaft grounding, typically outlasting the unit they’re installed on.
Helwig’s BPK-IM2, BPK-4, BPK-S, and BPK-AM Bearing Protection Kits are UL Recognized Components for both U.S. and Canada.
Testing on a 0.75 HP motor proved that a Helwig Bearing Protection Kit (BPK) is an effective shaft grounding solution. A Helwig BPK (model BPK-IM) was applied to the 0.75 HP motor. It consisted of an internal mounted grounding brush holder, with a proprietary silver graphite brush.
Measurements were taken for peak-to-peak voltage, number of discharges.
Shaft Voltage Unprotected