DC commutation relays are type of relay, which is used for DC load commutation pick-up and dropout simultaneously to the control voltage. Its advantages include no mechanical part in movement no recoil, compatibility with digital circuit, shock resistance and airtight seal. It can particularly be used where hight commutation frequency is required together with the possibility of commutating, by means of limited control voltage, high currents with 4KV insulation between input-output.