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 (BPK) and rings for motor shaft grounding. Our shaft grounding systems, also known as shaft earthing, effectively divert induced electrical currents away from the bearings, protecting them from damage and failure. What’s more, our bpk’s 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.
TYPICAL BPK APPLICATIONS: Motors with VFDs, HVACR, Pumps, Fans, and Blowers.
Other BPK™ Applications: static, atmospheric, and induced current sources.
Helwig offers an alternative mounting option when it is not possible to install a BPK radially on the motor shaft. Our axially mounted kits, which are typically for the non-drive end of the motor, have been used on pitch motors, compressors, refrigerant motors, fan walls, large HVAC units, and more! Standard and custom options available. Please call (800) 962-4851 for more information.
Effective shaft earthing from Helwig Carbon BPKs 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 our solution as their preferred method to protect motor bearings. Unlike other options, this sliding electrical contact technology uses a proprietary silver graphite material that provides superior voltage mitigation. Advantages of Helwig Carbon’s shaft grounding systems include:
Bearing Protection Kits™ mitigates shaft voltage and other electrical noise. The following oscilloscope screenshots compare induced shaft voltage with our BPK-4 vs. a carbon-fiber or shaft grounding ring. Lower voltage values is more effective for protection. Silver graphite is more than 5X lower in resistance than carbon-fiber, which significantly reduces the risk of induced shaft currents flowing through the bearings.
Unprotected Motor Shaft
Motor Shaft with Carbon-Fiber Ring
Motor Shaft with BPK-4
Reduces shaft voltage to well under 1 volt
Tough brush holder design for challenging environments
Only highly conductive silver graphite brushes in our BPKs
Increased motor performance, less maintenance
Kits will typically last 10 years or more*
Shaft grounding rings require a different model for each shaft size. Helwig BPK’s are one size fits most
The Helwig Carbon shaft grounding device – Bearing Protection Kits™ (BPK) – fit a variety of motor shafts, offer several mounting options, and are easy to install and maintain. Helwig Carbon bearing protectors will deliver many years of superior performance in motor shaft grounding and will typically last 10 years or more! Prevent bearing failure with Helwig Carbon’s motor shaft grounding ring BPKs today!
For motor shafts over 6 inches, please call Helwig Carbon (800)-962-4851
Helwig’s shaft grounding systems, BPKs, are specifically designed for contaminated environments. Our silver graphite brushes have a cleaning property that when combined with a constant force spring, provide a contaminant-free brush track. This maintenance-free solution is ideal for environments with excess grease, pickling lines, or volatiles in the air.
Helwig Carbon provides the shaft grounding industry the lowest resistant path to ground via a proprietary silver graphite brush grade to protect from damaging VFD-induced shaft currents. This one-of-a-kind brush grade is 5X lower in resistance than
Helwig Carbon Bearing Protection Kits (BPKs) are now available on WEG motors. We’ve partnered with one of the world’s most respected motor brands to offer shaft grounding pre-installed on new motors!
Helwig Carbon has been supplying OEM motor manufacturers with shaft grounding solutions since the mid-1990s. Since that time, the use of VFDs to control electric motors has vastly increased, thus increasing the need for shaft grounding and the demand for our after-market Bearing Protection Kits™ (BPKs).
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