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.
TYPICAL BPK APPLICATIONS: Motors with VFDs, HVACR, Pumps, Fans, and Blowers.
Effective shaft earthing and bearing protection 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 ring. Lower voltage values is more effective for bearing 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
Typically reduces shaft voltage to less than 1 volt up to greater than 1MHz
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*
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 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).
Electric motor bearings fail for a variety of reasons but the two most common reasons for electrical failure are circulating and common mode currents. Circulating currents are found in all motors. The severity of the problem and therefore the risk to the motor bearings is
October 13, 2020
August 21, 2020
August 21, 2020
August 19, 2020
May 21, 2020
April 28, 2020
April 15, 2020
April 6, 2020
March 25, 2020
March 24, 2020
We use cookies to improve your experience on our website. By closing this banner or interacting with our site, you acknowledge and agree to this.