New alternatives added to DRHX / MRHX range

Meet the new, constant-speed drive for rotary heat exchangers.
OJ Electronics has launched a new member of the DRHX family of drives for rotary heat exchangers. Designed for constant speed, the new variant was designed with simplicity in mind.

Offering a simpler alternative

Says product manager Preben Jessen: ‘The constant-speed variant was created by popular demand! Many of our customers expressed a wish to have a simple, constant-speed drive for rotary heat exchangers, so of course we complied. It’s basically a pared-back version of the existing DRHX range, making it ideal for those situations where you don’t need variable speed, but simply a reliable drive for your rotary heat exchanger. And we expect it to be very popular with many customers, not least in the Middle Eastern and Asian markets.’

Two DIP switches enable four speed settings

Essentially, the new DRHX variant comes equipped with a two-pole connector: when closed, the connected motor will accelerate to its maximum speed. When opened again, the motor will reduce the speed to stop and automatically perform an alarm reset. But there is scope for customisation to specific needs: ‘The new DRHX drive comes with two DIP switches,’ explains Preben Jessen, ‘which you can insert to suit the required speeds for your scenario. You can get four different speed settings this way, which gives you quite a lot of flexibility with this simple solution.’

Greater choice

Preben Jessen points out that the new, simpler DRHX model is part of OJ Electronics’ overall strategy to offer comprehensive choice: ‘We want our customers to be able to find what they need from us. So we regularly expand our product ranges to match the latest requirements from the market. Sometimes, that means adding – or inventing – sophisticated new technology. In other cases, as here, it means offering a simpler and/or more compact version of existing technology for situations where there’s no need to overshoot the project specifications. It’s all about giving our customers the chance to choose for themselves.’

More compact 1Nm motor

Speaking of choice: concurrently with the new DRHX drive, OJ Electronics also introduces a new 1Nm version of the MRHX motor. ‘Again, this new motor is a direct response to customer needs. With its 1Nm torque and 27W power, it fills in a gap at the low-power end of the range – and, very importantly, it offers a more compact alternative. It measures just 5.6 x 5.6 x 9.7 cm, so it’s easy to fit in. And you’ll note that for this model, we’ve gone for an elongated design, which many have asked for.’


The DRHX constant speed variant can be used with motor sizes ranging from the new 1Nm variant to the 8Nm model. The new 1Nm motor is compatible with the complete DRHX range with software version AOC 2.06 and MOC 2.07 or newer.

Key features of the constant-speed DRHX drive

  • Simple, constant-speed design
  • 4 speed settings via 2 DIP switches
  • One digital input for Start/Stop
  • Stepper motor solution
  • 230V AC single phase supply

Key features of the new 1Nm MRHX motor

  • More compact version – 56 x 56 x 97 mm
  • 1Nm torque
  • 27 W power
  • Slender design for installations where space is at a premium

The new constant-speed DRXH drive and 1Nm MRHX motor are available now. For more information and to order, please contact your sales representative.

For technical data, please go to the DRHX or MRHX product site.