Meet our new innovative rotary heat exchanger drives

Based on closed-loop sensorless motor control
The new DRHX range is OJ Electronics’ latest invention: drives and motors created especially for use with rotation heat exchangers – and based on field-oriented sensorless control. The new range uses the motor control topology familiar from our successful DV range: closed-loop sensorless motor control. Here you get a combination of a high-torque stepper motor and field-oriented sensorless control, which brings you a unique new solution – and great efficiency!

Eliminates sensors, guards and wear parts
With the DRHX drives, you don’t need an optical rotation guard sensor: the drive uses the feedback signal from the motor to calculate if the belt is broken. What is more, the feedback signal ensures that the motor gets exactly the current it needs to supply the right speed and torque. You don’t need wear parts – and you get operation that is more silent, more accurate and more energy-efficient.

Up to 65% system efficiency
With the new DRHX drives you get system efficiency – covering the drive and motor – of up to 65%. This is partly because the gear-free technology gives you perfectly accurate control throughout a wider speed range than ever. The drive also compensates for nonlinear heat transfer: it uses an inverted performance curve to automatically compensate the 0-10V signal, which gives you much more linear heat transfer and more accurate control.

Wide range – from 2Nm to 14Nm
The DRHX series covers the range from 2Nm to 14Nm with both Modbus and analogue control. You can even get versions with a 3x7-segment display if you want it.

Flexible installation
The application-ready DRHX units combine Modbus and analogue technology in very compact designs. Their small size makes them easy to fit in, and you can place them horizontally or vertically as you wish.

Easy access to connection points
All connectors and connection point are gathered in a single compartment just underneath the front cover. This makes access very easy, and every single connection is clearly marked. Installers and system designers will also appreciate how supply, motor and communication cables are easily installed through centrally positioned cable glands.

The new DRHX range of motor control solutions for rotary heat exchangers is available in 2Nm to 8Nm. 14Nm variant will be ready from November 2017.

The new DRHX range is based on closed-loop sensorless control, making them more accurate, efficient and silent than the geared motor solutions and stepper motor solutions currently found on the market.

The new DRHX range in brief

  • High-quality, highly reliable drive and motor solution.
  • System efficiency of up to 65%.
  • Gear-free technology ensures accurate control throughout wide speed range.
  • Sensorless rotation monitor – no physical/optical rotor guard is required.
  • Easy installation – compact, all-in-one units can be placed horizontally or vertically.
  • Easy access to all connections
  • Covers all requirements from the 2Nm to 14Nm range.
  • With Modbus and analogue control
  • Versions with or without 3x7-segment display available

About us

Introducing OJ Electronics
About OJ Electronics

For more than 50 years, we have designed and developed electronic controls for underfloor heating and HVAC.


to News
Subscribe to News

Sign up and receive the latest product news from OJ Electronics.


& Jobs
Careers & Jobs

We are always looking for people, who have the know-how and skills we need to create the best company possible.

Green Comfort

Intelligent Control
Green Comfort

Intelligent control results in maximum comfort with low energy consumption.