How to choose your 230V single-phase speed controller

A 230V single-phase speed controller is chosen first and foremost according to the current rating of the motor it must drive: the controller must always be sized to handle the maximum current shown on the motor's nameplate, never the other way round. Our range offers currents from 1.5A (for mechanical ventilation systems, T11 roof fans or small motors) up to 11A (autotransformer), with intermediate ratings at 3A, 4.5A, 5A, 7A, 8A and 10A.

Before ordering, check three pieces of information on your motor's nameplate: the voltage (230V single-phase for this category), the power rating and above all the current rating. An undersized controller will overheat, trip protection devices or damage the motor over time.

Voltage controller, autotransformer or converter

Most references in this range are standard voltage controllers, suited to single-phase double-inlet centrifugal fan motors (7/7, 7/9, 8/9, 9/9, 10/10, 12/12 depending on the model, such as the Var4.5ABASE, the Var8A or the Var8A10-12). For installations requiring smoke extraction, two autotransformers with 4 positions include a 400°C smoke extraction emergency push button (autotransfo7a at 7A, autotransfo11a at 11A), compliant with the C4 smoke extraction standard. These C4 models (400°C, 30 minutes) should not be confused with an F400/120 rating (400°C, 120 minutes): check the exact requirement of your project before choosing.

A third scenario applies to mixed installations: the MONO to TRI 1.5kW controller converts a 230V single-phase supply into 380V three-phase, in IP65 and C4 standard, useful when the available mains supply does not match the installed motor. The On/Off starter completes the range for simple control in 220V or 380V, without speed adjustment.

Adjusting airflow without stressing the motor

The speed controller lets you match extraction airflow to actual kitchen activity: lower the speed during quiet periods, increase it during service peaks. On motors compatible with speed variation, avoid prolonged running at low speed: each motor has its own documentation and its own cooling threshold, there is no universal percentage to follow.

Range comparison table

Points to check before ordering

• Check the maximum current shown on the motor's nameplate: the controller must handle it with no negative margin.
• Identify the motor size (7/7, 7/9, 8/9, 9/9, 10/10 or 12/12): some controllers in this range are explicitly dedicated to these sizes (Var4.5ABASE for 7/7 7/9 8/9, Var8A for 9/9 10/10, Var7Asaf for 12/12).
• Check whether your motor runs solely on 230V single-phase: a motor running on 380V three-phase requires a 400V three-phase speed controller, unless you have a specific need to convert single-phase to three-phase.
• If your installation requires smoke extraction, check the exact standard required (C4 400°C/30 min or F400/120 400°C/120 min) before selecting a model: the two ratings are not interchangeable.
• If the motor stops after 10 to 15 minutes of operation, have the duct diameter checked (under or over pressure in the ductwork) along with the power supply before suspecting the controller.

Complete your order with

To secure a smoke extraction installation, the smoke extraction push button and the emergency stop button usefully complement an autotransformer. The relay for 4-5 position single-phase controller is worth adding if your control setup requires several control points. You'll also find our 400V three-phase speed controllers for motors running on 380V, and the full range of commercial kitchen hood speed controllers.