Motor Control Solutions for Industrial and Material Handling Equipment

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Two-Speed BT™ Models

Two-Speed transitional A.C. soft start, reduced torque control.

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A two-speed BT™ Series unit; logic section and power bridge shown.

Do you need a soft-start that works with a single-speed motor? See our Single-Speed BT™ Models.

For smaller soft-start applications (under 7.5 HP), see our Smooth-Move® models.

For use with two-speed, 3-phase A.C. inductor motors. Soft-starting and low/high speed transitioning; reduced torque control.

Available Models by Line Voltage and HP Rating

Note: When filtering by HP rating, select the value that either meets or just exceeds your application specification. If an HP rating is not listed in one of the voltage columns, do not use that model at that voltage.

Model (Click to view product page)Max HP (kW) @ 208-230VACMax HP (kW) @ 460VACSelect Control Voltage and Line Frequency Optionshf:att:pa_230-hp-ratinghf:att:pa_460-hp-rating
BT746-2D4 HP (3 kW)7.5 HP (5.5 kW)
BT1046-2D5 HP (4 kW)10 HP (7.5 kW)
BT1523-2A15 HP (11 kW)
BT1546-2D7.5 HP (5.5 kW)15 HP (11 kW)
BT2523-2A25 HP (18.5 kW)
BT3046-2A30 HP (22 kW)
BT4023-2A40 HP (30 kW)
BT5046-2A50 HP (37 kW)
BT7546-2A75 HP (55 kW)

Select from these models if 575V is needed. If an HP rating is listed for 460V, the models may also be used at that voltage.

Note: When filtering by HP rating, select the value that either meets or just exceeds your application specification.

Model (Click to view product page)Max HP (kW) @ 575VACMax HP (kW) @ 460VACSelect Control Voltage and Line Frequency Optionshf:att:pa_575-hp-ratinghf:att:pa_460-hp-rating
BT757-2D7.5 HP (5.5 kW)7.5 HP (5.5 kW)
BT1557-2D15 HP (11 kW)15 HP (11 kW)
BT3057-2A30 HP (22 kW)
BT5057-2A50 HP (37 kW)
BT7557-2A75 HP (55 kW)

Select from these models if 380-415 VAC is needed. If an HP rating is listed for 230V, the models may also be used at that voltage.*

Note: When filtering by HP rating, select the value that either meets or just exceeds your application specification.

*50Hz is selected by default for these models, but 60Hz is available as an option.

Model (Click to view product page)Max HP (kW) @ 380-415VACMax HP (kW) @ 208-230VACSelect Control Voltage and Line Frequency Optionshf:att:pa_380-415-hp-ratinghf:att:pa_230-hp-rating
BT738-2D7.5 HP (5.5 kW)4 HP (3 kW)
BT1038-2D10 HP (7.5 kW)5 HP (4 kW)
BT1538-2D15 HP (11 kW)7.5 HP (5.5 kW)
BT3038-2A530 HP (22 kW)
BT5038-2A550 HP (37 kW)
BT7538-2A575 HP (55 kW)

About the BT™ Series; Two-Speed Models:

Upgrade your standard 3-phase two-speed A.C. induction motors with smooth starting, smooth reversing, smooth low-to-high speed, and smooth high-to-low speed, all with NO TIMERS! Through the control of all 3 phases for reduced mechanical and motor stress, you can practically eliminate breakage and wear on drive trains, gearing, belts, etc. The Two-Speed BT™ Series offers an easy and quick upgrade for new or existing equipment with 2-speed motors.

Two-Speed A.C. soft starts can be an electronic replacement for resistor ballasts, timers, fluid couplings, inductors and other electrical and mechanical systems used to “cushion start” 3-phase induction motors. A two-speed BT™ unit will even smooth out the previously rough transition between speeds! The controller can be used with single or multiple motors up to the total full load amperage rating of the model (see above tables). Smooth reversing is accomplished with a reversing contactor.

The two-speed BT™ models allow you to adjust the starting torque (ACCEL) of the motor, the transitional torque control between the two speeds (DECEL), as well as the length of the time to reach full motor torque/voltage (TIME). A unique patented system “senses” motor transitions, via the contactor coil control signals. Two-speed 2-winding motors or 2-speed consequent pole motors will operate smoothly in all transitions and speeds (see comparison graph of 2-speed motor characteristics with, and without the two-speed BT™ soft-start installed).

ARC-ELIMINATION™ is an exclusive feature of the high-reliability Power Electronics soft-start controls. This feature eliminates the destructive arcing on the make & break of power contactors. With the Smooth-Move installed, the life of your contactors will be extended up to their mechanical limit, and IEC style contactors can now replace the more expensive NEMA style contactors in many applications. Additionally, the control will have very high reliability in tough applications. Only available from Power Electronics Intl.!

Product Features

  • Takes the "kick" out of 3-phase motor starting.
  • Phase loss protection on input.
  • ARC-ELIMINATION™ on contactor make-and-break extends contactor life up to the mechanical limit.
  • Automatic UNIVERSAL VAC selection: 208, 230, 385, 415, 440, 480, VAC in one unit (200 and 575VAC also available)
  • 110VAC Control Voltage input is standard – all other voltages available upon request
  • Unit is the size of a small contactor
  • TIME and TORQUE settings for motor softness.


  • Easy to install and run
  • Use with reversing and non-reversing systems
  • Extend contactor life up to their mechanical limit
  • Higher reliability
  • Saves $ on machinery life and productivity

Important Notes

  • For single-speed A.C. motor soft-start control, view the Single-Speed BT series.
  • For two-spee soft-start applications with smaller full-load-amp requirements (10A max), view our Smooth-Move® 2 models.
  • Once you find the right Smooth-Move for your application, let us build you a completely customizable and turnkey control panel for your project! Call us today for a quote, or start your project here.

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  • Listed for U.S. and Canada

Product Downloads


If you have a single-speed or two-speed 3-phase motor, make sure you are looking at the corresponding single-speed or two-speed control unit models. Standard Smooth-Move torque controllers can be used at nearly any 3-phase voltage (208 – 460VAC). Models ending with “57” have an extended voltage range of 208 – 575VAC. The controller can be used with single or multiple motors up to the total full load amp rating of the model. Use the product tables above to find the model that meets the FLA rating requirement of your motor(s). If your application requires higher amperage ratings than those listed here, view our BT Series of soft-starts.

If you are looking to reduce wear on your motor and connecting components due to starting “kicks”, a Smooth-Move® soft-start is a good economical option. However, as the name implies, a soft-start only helps with motor “starts”.

Also note that Smooth-Move controllers are not intended for use in hoisting applications – VFD or closed-loop motor control is required in these applications. Also, if you need to control your motor speed while running, if you need to control the deceleration of your motor, or if you need your system to be capable of more advanced programming, a VFD will likely be a better upgrade option. View our line-up of Micro-Speed products here.

Contact PE if you require any further help with selecting the correct soft-start or VFD for your application.

If you have a two-speed motor and you would like to upgrade to one of our Micro-Speed® VFDs for better speed control, you will need to hook up the PE® VFD to the motor’s high-speed windings only. In this case, be sure to size the VFD based on the high-speed winding HP/Amp rating.

If you plan on using a Smooth-Move® or BT™ soft-start unit with this motor, be sure to select a model that works with two-speed motors.

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