Using drives with Ex motors made easier by ABB’s certification

ABB has done extensive testing of motors and drives for potentially explosive atmospheres and can provide certification for Ex applications.

You probably know that explosions may occur in your processes when air is mixed with flammable gasses, vapors, mist or dust. All that’s needed is the right concentration of such materials and a source of ignition.

Explosion risk is elevated in a broad range of industries and processes. An example is food and beverage processing, where grain storage silos are at risk due to high levels of grain dust mixed with air. If a motor in such an environment overheats for any reason, an explosion can be detonated.

. . . Therefore it is important to understand how to ensure safety in potentially explosive atmospheres and what items must be taken care of.

Ex helps to ensure safety

Numerous key issues need to be considered concerning motors and drives in such environments. For example, a wrongly dimensioned or installed drive may cause a motor to malfunction, perhaps resulting in overheating or sparking. It’s important to note that a spark is not always required to ignite an explosion; your hot motor alone can do it.

To keep people and property safe, the ‘Ex’ standards have been established. The Ex label indicates you can trust a motor is safe to use in a designated explosive atmosphere. Any motor you select for a potentially explosive area must have the Ex label.

. . . Furthermore, any drive controlling such an Ex motor must always be located in a separate ‘safe area’, even if the drive is Ex marked and equipped with integrated certified safety functions. The main reason for this is that Ex certification in drives is only intended to certify that the safety functions operate as the standards demand. But the device itself is not built to fulfill the requirements for installation in Ex area.

Cost efficiency, and safety, combined

Looking from a financial viewpoint, meeting the safety standards in the most cost efficient way depends very much on you choosing the right combinations of motors and drives.

This is where ABB can fully support you. We have deep and valuable knowledge and expertise with design, testing and certification of motors operating with drives in explosive atmospheres. Our portfolio of Ex-certified motors and drives is extensive, and growing for the future.

. . . Going one step further, we are one of the very few manufacturers who supply our own complete ABB motor-drive combinations that are specifically tested and certified for safe operation in explosive environments. This helps you, as a process designer or engineer, feel confident that you are getting the best motor-drive solution for safe operation.

For any Ex application, your easiest option is to select a dimensioned ABB motor-drive Ex solution. These are type-tested, dimensioned and certified together, according to the IECEx and ATEX standards. Thus you save time, money and hassle in meeting the standards.

Easy combining with non-ABB motors

. . . In case you want to use a non-ABB motor, our drives offer easy compatibility via an optional integrated ATEX-certified thermistor protection module. When the motor sensor indicates an over temperature, the PTC module will activate certified Safe Torque Off (STO) function of the drive, thus preventing the inverter from generating the voltage required to rotate the motor. The thermistor protection module together with the STO function is a valid Safe Motor Temperature (SMT) function as defined in EN/IEC 61800-5-2.

This flexible compatibility with non-ABB motors means you can easily meet the safety standards for such mixed motor-drive packages, even though they have not been tested together. Before combining the ABB drive, you must simply verify that the motor is designed to operate together with a drive.

Flexibility covering yesterday, today and tomorrow

And for operations that are currently using ABB Ex motors with older ACS600 or ACS800 drives, those can be replaced with the all-compatible ACS880 and the Ex certificates are still valid.

Your end result is this: Selection, installation, retrofitting and replacement of drives and motors packages for explosive atmospheres has never been easier or more cost effective. Whether you are an EPC designer, end-user, OEM or distributor, these ABB solutions will give you the highest degree of safety and flexibility for a long time into the future.

. . . and the peace of mind of knowing that you have made the right decision.


Do you want to learn more about using motors and drives in applications located in potentially explosive atmospheres?

ABB’s Ex motor offering:

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About the author

Katja Pulkkinen

I'm the Product Manager for motor and drive packages, including the ACS310 variable speed drive. It is interesting to create offering of safe and reliable motor-drive packages for our customers. Before joining to ABB I worked in Nokian Tyres, TTT technology, Nokia and Fibox. In my spare time I like to take long walks with my dogs, fix the house, ride horses and drive my motorcycle.
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