NEWS

The certificate can be consulted directly on the IECEx website: https://www.iecex-certs.com/#/deliverables/CERT/2160538/view

This was the next step, already announced after the IECEx certification of our motors, to complete the range. The aim is to ensure that an Ex Motive gearbox mounted on an Ex Motive motor does not reduce the certified safety level of the assembly.

The risk of an explosion being ignited by a non-electrical product such as a mechanical gearbox is often underestimated, but wrongly so. We explained this here: https://www.motive.it/en/articoli-143-does-it-make-sense-to-put-an-ex-motor-with-a-non-ex-gearbox-.html. This is why Ex standards and certifications also exist for mechanical gearboxes. For ATEX Category 2 gearboxes (Zones 1, 2, 21 and 22), however, the European procedure only requires the mandatory deposit of a comprehensive technical file with a Notified Body, in accordance with Directive 2014/34/EU. See, for example, this TÜV certificate: https://www.motive.it/upload/documenti/manuali/Certificato_ATEX_Riduttori_TUV.PDF.

Although a Notified Body is involved, for non-electrical products this procedure is not equivalent to full product certification: unlike the situation for electrical products such as motors, the body does not assume the same certification responsibilities. IECEx is a genuine certification scheme in which the certification body assumes its responsibilities.

The European ATEX Directive also requires manufacturers to have their Quality Management System certified according to ISO/IEC 80079-34 (see https://www.motive.it/en/articoli-92-not-only-its-products-but-also-motive-itself-is-atex.html). This requirement does not apply in the same way to manufacturers of non-electrical products. IECEx certification therefore introduces mandatory periodic surveillance of mechanical gearbox production by the certification body.

When checking the official IECEx database, we found that no other manufacturer offers a range of flanged industrial mechanical gearboxes, separate from the motor, covered by IECEx certification. For motors, Motive undergoes annual audits for both ATEX and IECEx according to ISO/IEC 80079-34; mechanical gearboxes are audited only under IECEx.

LOWER HEATING = HIGHER AMBIENT TEMPERATURE POSSIBILITIES

In addition to enhanced safety, we have introduced upgrades to ensure that an Ex Motive gearbox does not have a lower safety level than the Motive motor. Mounting an Ex Motive gearbox on an Ex Motive motor therefore does not reduce the certified safety of the gearmotor assembly.

In the temperature configuration normally required for our Ex motors, in continuous-duty mode S1, the motor—especially in the IE3 version—runs so cool, thanks to its low power losses, that it can operate at an ambient temperature of 60 °C. Previously, our Ex gearboxes could be installed at ambient temperatures up to 40 °C. The new certificate clarifies that the gearbox also maintains an internal temperature compatible with class T4 (maximum 135 °C), allowing installation at ambient temperatures up to 60 °C, as for the motor.

T4: gearbox coupled with 2-, 4-, 6- or 8-pole motors, at ambient temperatures up to 60 °C.

Since 2025, our motors have also been certified for lower ignition-temperature requirements, corresponding to classes T5 and T6. We have extended these options to the gearboxes too: T5: gearbox coupled with 4-, 6- or 8-pole motors, at ambient temperatures up to 50 °C; T6: gearbox coupled with 4-, 6- or 8-pole motors, at ambient temperatures up to 40 °C.

The Motive configurator now also shows the availability of ATEX T5 and T6 gearboxes. The maximum surface temperature is aligned with that specified in the new ATEX and IECEx motor certificates, with a limit of 120 °C. The new markings are: Ex h IIC T6...T4 Gb; Ex h IIIC T85°C...T120°C Db.

All gearbox series are included: BOX – Worm; ENDURO – Helical bevel; ROBUS – Helical in-line; STADIO – Pre-stages; STON – Helical parallel shaft.

OPERATION AT 60 Hz AND PERMITTED SPEEDS

The IECEx certificate also clarifies that the gearboxes can operate at 60 Hz. Two-pole motors are also permitted as input motors when the maximum required gas temperature class is T4.

3,600 rpm: T4, ambient temperature −20 °C to +60 °C.

1,800 rpm: T5, ambient temperature −20 °C to +50 °C.

1,800 rpm: T6, ambient temperature −20 °C to +40 °C.

A COMPLETE RANGE, COMBINING SAFETY AND APPLICATION FLEXIBILITY

These requirements add to those already in place for both motors and gearboxes. In the ALL-IN-ONE version, our Ex motors and gearboxes together cover all Ex gas groups (A, B and C) and dust groups (A, B and C), for Zones 1, 2, 21 and 22 and Categories 2 and 3. The motors are also certified for operation with inverters without compromising their safety level, and are suitable as standard for duty types S1, S2, S3, S4, S5, S6, S7, S8 and S9. This comprehensive range enables us to offer a level of safety and application flexibility that is difficult to match.

We also offer ATEX inverters for motor-mounted installation, certified for explosive dust atmospheres, for all specified groups (A, B and C). In food processing, agriculture, woodworking and mining, an Ex variable-speed gearmotor can therefore be configured without necessarily placing the inverter outside the hazardous area or enclosing it in a flameproof cabinet. The Motive configurator makes it easy to identify a plug-in solution to suit your needs.

DO IECEx GEARBOXES COST MORE?

The answer is no. As with IECEx motors, the gearboxes remain at the same prices as when they were certified only to ATEX. From now on, in addition to the ATEX marking, the nameplate of Ex gearboxes will also carry the IECEx marking.