The Baldor-Reliance® EC TitaniumTM is a highly efficient motor paired with a VFD (Variable Frequency Drive) that enables the use of advanced motor control algorithms for higher efficiencies across the speed and load range than traditional EC (electrically commutated) motor solutions. By utilizing a drive to control motors, up to 40% energy savings are achieved.
Motors controlled by VFDs are beneficial because they provide speed control on applications such as fans, pumps, and conveyors, allowing users to run their motors at optimum efficiency.
VFD switching frequency creates a parasitic capacitance between the rotor and stator and induces a voltage or the rotor shaft. This is known as common mode voltage and at sufficiently high levels it will create a discharge of current to ground. Current that finds its way to ground through the bearings is called bearing current. In certain applications the resulting electrical discharge will damage and cause bearings to fail prematurely. This current flow, if not addressed, could even pass through a non-insulated coupling into the driven equipment and cause premature failure of components within the rest of the system.
The problem is, it’s hard to predict which applications will have problems and those that will not.
The need for proper motor grounding is extremely important in preventing premature bearing failure which could result in high maintenance costs or worse - facility downtime. While there are several techniques and practices to ground the motor, most common and economical is a shaft grounding device mounted to the frame of the motor.
Shaft grounding brushes provide an alternate low-impedance path from the motor shaft to the motor case. This channels the current away from the bearings. It effectively eliminates shaft voltage, and therefore bearing current, which occur when voltages induced in the motor rotor and shaft are discharged to earth through the bearings causing premature failure.
The EC Titanium incorporates the shaft grounding brush as standard on all models. By pairing the VFD with the motor, there’s a need to protect against bearing currents. Our shaft grounding brushes are internally mounted to prevent voltage spikes from damaging the bearings.
To find out more on EC Titanium and how this will help with your pump, fan, or compressed air system efficiencies, watch this video here: