EMI - Broad spectrum electromagnetic noise interference either conducted on the power line directly from the source or radiated to the power line then conducted to the susceptible equipment. RFI - Electromagnetic noise interference in the radio spectrum. TVI - Electromagnetic noise interference in the television spectrum. EMP - A very large and very fast rising electromagnetic pulse caused by catastrophic events such as lightning or nuclear detonation. Harmonic - Harmonics are sinusoidal currents and voltages with frequencies that are integral multiples of the fundamental power line frequency.
Harmonics distort the normal sine wave.
Also called the transverse or metallic mode. MOV - Metal Oxide Varistor. A voltage dependent resistor. A low cost but very effective protection device. They can handle large surges and switch in 1 to 5 nanoseconds.