Manufactured and supplied. Product is certified. RTT5-10 series thermal overload relays are designed to protect three-phase squirrel-cage induction motors from current overloads of unacceptable duration, including those occurring due to the loss of one of the phases. Relays are used as components in electric drive control circuits in AC circuits with a voltage of 660V at 50 and 60Hz, and in DC circuits with a voltage of 440V.