This specification prescrives limits of radio interference in terms of noise voltage and noise filed intensity throughout the frequency range, 0.4 Mc/s to 300 Mc/s. The specified limits apply to electrical equipment, other than radio receiving equipment for audio or visual reproduction, in which the intentional generation of radio frequency is not inherent in the design or operation of the equipment, and which is intended for connection to a low or medium voltage supply, i.e., having a difference of potential between conductors not exceeding 650 volts.