Specifying and Sizing Motor Starters

There are four basic motor control options available: Basic contactors, traditional starters, manual motor starters, or combination starters. A basic contactor is a special purpose relay that is used to control large electrical currents. Similarly, a traditional starter utilizes overload relays, auxiliary and alarm contacts, and mechanical interlocks to create a reversing unit. On the other hand a manual motor starter is a protective device for motor use that provides optimal protection by integrating the functions of a molded case circuit breaker and thermal overload relay into a compact unit. In comparison, a combination starter is comprised of combining a manual motor starter and a magnetic contactor to achieve a compact motor control that minimizes enclosure space requirements.

Simply follow these 3 steps to choose the best fit.

 

1. What Does the Application Require?

Basic Contactors Only 

Motor Starters

Contactor

Typical Applications

  • Electronic switching
  • Lighting
  • Resistive loads
  • Non-motor-related inductive loads
  • Disconnect switches
  • VFD bypass/isolation

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Traditional Starters 

Motor Starters

Contactor and Overload Relay

Typical Applications:

  • Inductive motor starting and control
  • NEC 430 and 409 fulfillment
  • Nm starter replacement/ retrofit

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Manual Motor Starters

Motor Starters

Manual Motor Starter (MMS)

Typical Applications:

  • Inductive motor starting and manual control
  • NEC 430 fulfillment
  • Lockout/tagout
  • UL 508, type E
  • Not AC-4 rated

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Combination Starters 

Motor Starters

Manual Motor Starter, Contactor, Link Module, and Base Plate

Typical Applications:

  • Inductive motor starting and control
  • NEC 430 and 409 fulfillment
  • Lockout/tagout
  • UL 508, type F

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2. Consider These Factors When Selecting Components:

  • Load type: Resistive (AC-1) or inductive (AC-3)
  • Duty cycle: One direction, reversing, plugging (AC-4)
  • Horsepower (hp) and full load amperage (FLA)

 

3. Select Your Components.

Parts listed here are Fuji motor controls components available at www.AutomationDirect.com/motor-controls.

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Duo Series

SC-E Contactor

  • 1/2 to 100 hp @ 480 V
  • 9-150 A (AC-3)

Odyssey Series

3N Contactor

  • 60 to 300 hp
  • 180-361 A (AC-3)

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Duo Series

SC-E Contactor

TK-E Overload Relay

  • 1/2 to 100 hp @ 480 V

Odyssey Series

3N Contactor

3N Overload Relay

  • 60 to 300 hp

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Duo Series

BM3 Manual Motor Starter

  • 1/2 to 40 hp @ 480 V

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Duo Series

BM3 Manual Motor Starter

SC-EContactor BZ0L Link Module

BZ0BP Base Plate

  • 1/2 to 40 hp @ 480 V

 

If you would like to learn more visit www.AutomationDirect.com/motor-controls.

Motor Starters