SCR Rated DC Motors

"SCR" rated DC motors feature a "silicon controlled rectifier" and are used with phase-controlled SCR or pulse width modulated DC drives due to the motor's ability to handle additional heating.  Permanent magnet DC motors are often SCR rated as well as some wound field DC motors.  DC motors that are SCR rated may be used in a variety of industrial applications, including machine tools, medical equipment, pumps, material handling, packaging and electric vehicles. 

In order to handle the vibration, de-rating issues and excessive heating, SCR rated motors have certain characteristics.  These include NEMA rating with Class H insulation, dynamic balancing (for reduction of vibration), TEFC or TEBC enclosure, zinc coating that's resistant to rust, armatures that are impregnated with polyester varnish to withstand high temperatures, and sealed ball bearings that are oversized and feature grease that withstands high temperatures.

The totally enclosed TEFC and TEBC enclosures both provide cooling by use of an external fan or blower.  The enclosures also limit the entrance of any contaminants such as oil, dust, chemicals, etc. that can harm the motor and possibly cause winding failure.  The insulation type, Class H, is also crucial to the protection of the motor because this type can withstand a maximum operating temperature of 180 degrees C with a temperature at full load of 105 degrees C.

If your company has need of an SCR rated NEMA DC motor, check out these DC motors by Hallmark Industries.  Multiple horsepower ratings available to meet a variety of application needs.