Skip to main content


Call 1.888.577.6877

Home > Rotary Switches

Rotary Switches

Rotary Switch Manufacturer, Rotary Electrical Switch, HVAC Switch, Resistive Or Motor (Inductive) Load

Rotary Switch Diagram

Carson rotary switches are versatile, durable and economical line-voltage devices designed for multi-tap motor speed selection. These switches are UL and CSA recognized for resistive and fractional horsepower motor (inductive) loads, and sized to easily fit single-gang switch box installations. Several HVAC Industry leaders like International Environmental, Trane, McQuay, Airtherm, Hydro-Air, Bryant and Carrier have trusted Carson rotary switches since they were first introduced in 1948.

Built with heavy duty components, Carson rotary switches are great for commercial building fan controls, industrial fans, farm fans, sports fans, floor polishers, food service equipment, portable heaters, blowers and dryers. Through unique construction Carson rotary switches can easily be customized to meet a variety of application requirements.


  • 10 Amps – 1/4 HP at 125 VAC
  • 5 Amps – 1/2 HP at 250 VAC
  • 5 Amps – 1/4 HP at 277 VAC

RU Logo
CSA Logo

Available Rotary Switches

Replacement Rotary Switches

Except for the Standard or Custom rotary switches described below, our rotary switches are custom built and proprietary to OEM customers – we do not sell direct. Carson Manufacturing can direct you to the appropriate OEM to contact. In order to provide you with a fast and accurate response to your replacement switch search, identify the part number and contact Carson Manufacturing with part number and quantities.

Where to Find the Part Number

The part number will be located on the back of the switch at the bottom of the board. Older switch models will reflect an embossed part number, while newer switch model part numbers will be affixed with a label. Example part numbers in red below.

Photo of an older Carson rotary switch
Older Switch Model
95-13 3A162
M91 3A 245
Photo of a newer Carson rotary switch
Newer Switch Model
3D312 11-32

Standard Rotary Switches

Carson Manufacturing offers a variety of commonly used switch types that will satisfy most all applications, such as commercial building fan controls, industrial fans, farm fans, sports fans, floor polishers, portable heaters, blowers and dryers.


  • 10 Amps – 1/4 HP at 125 VAC
  • 5 Amps – 1/2 HP at 250 VAC
  • 5 Amps – 1/4 HP at 277 VAC
Rotary Switches

Standard Switch Options

Standard Switches and Options

3A254 3D312 3TA252 XXXXXX-2 XXXXXX-3
SP3T W/Off SP3T W/Off Double Contact SP3T W/Off Isolated Aux Contact Wall Plate, Screws* & Knob, Bulk Pack Wall Plate, Screws* & Knob, Indiv. Pack
3A254 Rotary Switch Options 3D312 Rotary Switch Options 3TA252 Rotary Switch Options Fan Control Rotary Switch Options
Includes 6″ #16 GA Lead Wires and Fiber Insulator with Printed Wiring Diagram.
*#6/32 X 1/2″ Oval Head Screws Attached to Wall Plate.

Custom Rotary Switches

Carson rotary switches can be configured for your special application requirements. We offer a broad range of construction options to fit your needs. Most commonly available options can be supplied in small volumes within 2-4 weeks. Contact Carson Manufacturing for your specific switch needs.

Custom Rotary Switches

Series ‘A’ Rotary Switch

  • Single contact (1 pole)
  • 2-8 positions

Series ‘D’ Rotary Switch

  • Double contact for 2 common circuits (1 pole)
  • 2-6 positions

Series ‘TA’ Rotary Switch

  • Single contact (1 pole)
  • Isolated auxiliary circuit used for light, valve, contactor, etc.
  • 2-4 positions

Series ‘S’ Rotary Switch

S Series Rotary Switch and Diagram
  • Combines any two “A,” “D” or “TA” switch decks (2 pole)
  • UL recognized only

Commonly Available Options

Common Rotary Switch Options - Degrees
  • 0° or 15° offset
  • Special contact arrangement, such as center off
  • Male 1/4″ quick connect terminals
  • #18 or #16 GA PVC insulated lead wires cut to customer’s desired length, with common lead colors immediately available
  • Can mix terminals and leads on same switch
  • Wall plate mounted assembly for single-gang switch box installation.
  • Bracket mounted assembly for single-gang switch box installation with commercially available wall plates.
    (Note: Knob for 1/4″ shaft with set screw can be used)
  • Black winged push-on knob for square shaft.
    (Note: Knob for 1/4″ shaft with set screw can be used)
  • .03″ Protective fiber insulator can be printed or labeled (leads only)
  • Available without bushing for screw or pop-rivet mounting
  • Individually or bulk packed for shipping
  • White aluminum wall plate with slotted white head screws (#6-32×1/2)
Rotary Switch Special Options

Special Options

Additional lead time and/or setup costs may apply.

  • D Shaft, round shaft, shaft-less (keyed), screw driver slot
  • Various mounting screw lengths
  • Lead termination and/or connector assembly
  • Special wall plate printing

Contact Us

For more information regarding replacement, standard, or custom rotary switches, please contact us or call 888.577.6877.