Culver Armature and Motor

Beware Bearing Currents….Marathon Electric Announces “SGR”

Tired of premature bearing failures?....me too! It gives me great pleasure to introduce the Shaft Ground Ring or SGR, the latest innovative product addition to our extensive line of field installable kits. Given the fact that we are the leaders in Variable Frequency Drive (VFD) motors with the MAX motor family, it should be no surprise that we have raised the bar again with this new solution to a very real problem with VFDs. We have spent hundreds of hours testing and understanding the interaction between the VFD and the AC induction motor, we discovered that the problem exists with all VFDs and all the motors they control. While VFDs deliver impressive energy savings (up to 30% or more), they also introduce harmful common mode voltages (CMV) onto the shaft of those motors. The resulting currents will damage motor bearings, which result in costly downtime and premature motor failure. Any truly “green” process must achieve sustainability as well as energy efficiency. The SGR kits make this possible by dramatically extending the lives of motors controlled by VFDs.

Power and cost savings via Optibelt Service Tools

When dealing with V-belts and ribbed belts, a level of tension that is too low leads to the unnecessary slipping through of the belts, an issue that is usually difficult to notice. This additional friction that can lead to the burning of the belt creates unnecessary heat losses. With regards to V-belts and ribbed belts, a level of tension that is too high leads to an unwanted distortion of the belt composition. When dealing with timing belts, it is also the case that the teeth do not engage cleanly if the tension level is too high or too low and then become distorted.

As is the case with friction, matters such as unnecessary distortion always lead to heat losses that are simple to avoid. The method of setting the tension by using the thumbprint method no longer works when dealing with the technologically demanding drive belts of today.

6 to 12 and 35 to 50 Watts Solid State Commutated Unit Bearing Motor

Direct Drop-In Replacement for Motors 6 to 12 Watts and 35 to 50 Watts Output

• Rotation is determined by viewing opposite shaft end
• Ultimate commutated technology
• Unit bearing construction
• 100% performance tested
• Constant 1550 RPM operating speed is identical on either 50 or 60 Hertz
• Constant 1550 RPM regardless of fluctuations in voltage
• Includes LYALL plug ( Model 10012 )
• Includes water shield to protect motor during coil cleaning ( Model 10012 )
• Peak efficiencies in excess of 80% means lower operating temperatures and extended motor life
• UL recognized and electronically protected