Leeson Speedmaster DC controls are general purpose drives designed for use with permanent magnet type direct current motors. NEMA 1 enclosed drives are suitab for most industrial applications, with the NEMA 4X enclosures best suited for washdown or outdoor installations or for extremely dusty applications. Chassis only units are available for building into equipment, machinery or existing enclosures. Most controls have a dual voltage switch allowing the control to be used on 115v or 230v, single phase, 50/60hz. However, the proper voltage motor should be sected for use with the power supply input, i.e. 90V DC motors for 115volt input or 180V DC motors for 230volt input service. Installation and adjustment instructions are included.