Relpol RM51 Series Miniature Relays. Relpol RM51 series miniature relays for general purpose applications. The RM51 relays are designed for PCB mounting and are suitable for a wide range of applications such as household electrical appliances, automation systems, electronic equipment, instrument and meter, telecommunication devices and remote control facilities. Features and Benefits. DC coils. High load up to 20 A (DC). Compact size. High shock and vibration resistance