Explosion-proof motors can be driven by inverters

SEW-Eurodrive says it was the first company to obtain certification from the Physikalisch Technische Bundesanstalt in 2006 for the first AC motor in protection type e for operation with a frequency inverter. This basic type of approval was implemented for all four-pole motors of category 2 from SEW-Eurodrive and certificates are now available for all eDT and eDV motors. The new approvals for the motors were performed according to the new European standards applicable to explosion protection: Gas (EN 60079-0; EN 60079-7) and dust (EN 61241-0 and EN 61241-1).

The advantages this combination offers compared to an AC asynchronous motor in explosion protection type d (EN 60079-1; flameproof enclosure) are as follows:

• The motors are compatible with any frequency inverter from SEW-Eurodrive
• High efficiency
• Low weight
• Short delivery times and high availability
• Suitable for pump and fan drives
• Supplied from one source

These motors meet the requirements for equipment intended for use in potentially-explosive areas of category 2 as defined in directive 94/9/EC (ATEX 95). A device for direct temperature monitoring in combination with the defined operating parameters of the frequency inverter offers the best possible protection against excessive heating caused by an overload.