If you occasionally encounter unexplained phenomena such as flickering lights, sounding alarms, or unexplained tripping of miniature circuit breakers (MCBs), molded case circuit breakers (MCCBs), residual current devices (RCDs), and leakage protection devices, there is a high possibility that harmonics are present in your electrical environment. Other signs are cables running hot, hot switchboards or overheating motors. If you are replacing your motor’s bearings & insulation often, that’s a strong indication of the presence of harmonics.