LEESON Speedmaster® DC controls are general purpose drives designed for use with
permanent magnet type direct current motors.
NEMA 1 enclosed drives are suitable 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 115 or 230 volt, single phase, 50/60 Hertz service. However, the proper voltage motor
should be selected for use with the power supply input, i.e., 90 volt DC motors for 115
volt input or 180 volt motors for 230 volt input service. Installation and adjustment
instructions are included.
SCR/Thyristor drives are available in unidirectional and electro-mechanical type
reversing styles for NEMA frame ratings and sub-fractional HP sizes.
Regenerative, four quadrant controls in NEMA 4X or chassis style available for
applications requiring more precise motion control. These controls will produce both
motoring and braking torque regulation for NEMA frame 1/4 HP through 2 HP motors.
Pulse Width Modulated (PWM) controls are available in NEMA 1 and chassis style units
for subfractional HP frame motors from 1/40 through 1/4 HP. Due to their improved form
factor, these PWM controls will result in quieter operation, lower operating
temperatures, longer brush life, and greater motor overload capacity than for the same
motor on an SCR type control.

LEESON Electric