WHY SPECIFICATION MATTERS
The increased adoption of variable frequency drives (VFDs) over the past decade has elevated the need for specifically engineered wire and cable solutions that ensure long-term performance. To avoid costly downtime, diagnosis, and repair of these critical operations, it is important to specify cable and termination systems designed to address motor bearing failure, cable failure, stray current, and electromagnetic interference (EMI).
However, there is some confusion in the market when it comes to specifying the right cable system and termination method that can optimize performance and improve longevity of motors utilitzing VFDs.
IMPORTANCE OF CABLE CONSTRUCTION
The higher switching speeds of VFDs inherently generate more EMI that inevitably gets radiated into the environment by the inverter-to-motor power cable. The EMI emitted from the power cable can induce voltages, crosstalk, or common-mode currents onto adjacent cables and equipment, causing damage to control systems and mechanical parts.
To avoid these issues, it is important to choose an electrically balanced, shielded cable with NFPA 79 compliant crosslinked polyethylene (XLPE) insulation when specifying cable systems for VFD applications. For the best performance, a RHW-2 2kV rated cable design has superior dielectric properties to resist voltage spikes that are generated during operating conditions. Increased insulation thickness results in less impedance mismatch to the system and fewer issues with reflective wave phenomenon.