Systemair Fan Speed Controllers

Frequently asked questions

How do I choose the right speed controller?

Start with the fan motor, not the controller. Check whether the fan is AC or EC, and if AC whether it is single phase (230V) or three phase (400V), then check its full load current in amps on the rating plate or datasheet. Choose a controller of the matching type with a current rating at or above the fan's full load current. If you are running more than one fan from one controller, add their currents together.

AC or EC: why does it matter?

An AC fan's speed is controlled by varying the voltage, using an electronic or transformer controller. An EC fan has its speed control built into the motor and takes a 0 to 10V signal or a potentiometer, so it needs an EC controller such as the MTP10. An AC controller will not control an EC fan, and fitting the wrong type is the most common reason a controller does not work.

Electronic or transformer controller?

Electronic controllers such as the REE and ITR are compact and give smooth, stepless speed control at a lower price, which suits most single fans. Transformer controllers such as the RTRE (single phase) and RTRD (three phase) step the voltage down in five fixed steps. They run the motor more quietly with no electrical hum at low speed, are kinder to the motor and are the usual choice on larger fans and commercial systems.

Can I control a three phase fan?

Yes. The RTRD range gives 5-step transformer control for three phase fans from 2A to 14A. The FRQ5 is a frequency inverter with a 5-step switch for three phase fans, available in 4A and 10A. The FRQ5 is not intended for external rotor motors, so check the fan type before choosing it.

What are the thermostats and sensors for?

The RT 0-30 room thermostat and the TG-R5 PT1000 sensor let a fan or controller react to temperature, for example running ventilation harder when a plant room or warehouse heats up. Check the controller you are pairing them with accepts the sensor type.

Do you supply controllers for trade and projects?

Yes. We supply electricians, M&E contractors and facilities teams. Send us the fan models or a schedule and we will match each fan with the right controller. Call 0161 399 3825 or email hello@efans.co.uk.