Choosing the right ATEX motor for your installation starts with correctly establishing the zone classification. Get this wrong and you either overspend on over-specified hardware, or worse, create a serious safety risk. This guide walks you through zones, protection methods and the practical trade-offs that save both money and lives.
What is an ATEX zone?
An ATEX zone classifies how likely an explosive atmosphere is present in a given area. The classification depends on the type of explosive substance (gas or dust) and the frequency of its presence. The European ATEX Directive 2014/34/EU regulates equipment for use in such zones; internationally the IECEx scheme covers the same ground.
For gases, vapours and mists: Zone 0 (continuous risk), Zone 1 (likely during normal operation), Zone 2 (unlikely, only briefly). For dusts: Zone 20, 21 and 22 follow the same logic. A motor installed in the wrong zone can ignite the atmosphere and cause an explosion, this is why zone classification precedes motor selection
Protection methods: Ex db, Ex eb, Ex ec, Ex tb
Each zone requires a specific motor protection method. The higher the zone risk, the more stringent the motor construction:
- Zone 1/21: Ex db (flameproof enclosure), contains any internal ignition. Heavy cast-iron construction, certified gap dimensions. Most common for process industry.
- Zone 1/21: Ex eb (increased safety), no sparks or hot surfaces under normal operation. Combined Ex db eb motors carry both certifications for maximum flexibility.
- Zone 2/22: Ex ec (non-sparking), lighter construction, typically 30-40% cheaper than Ex db. Sufficient where the explosive atmosphere is unlikely.
- Zone 21/22 dust: Ex tb/Ex tc (protection by enclosure), dust-tight IP66 construction with limited surface temperature
Gas groups and temperature classes
Beyond zone and protection method, motors are classified by gas group and temperature class. Gas groups IIA (propane), IIB (ethylene) and IIC (hydrogen, acetylene) indicate which gases the motor is certified for, IIC is most stringent and covers all groups. Similarly, temperature classes T1 (max 450°C) through T6 (max 85°C) indicate the maximum surface temperature; T4 (max 135°C) is sufficient for most industrial applications.
A typical specification reads: II 2G Ex db IIC T4 Gb, meaning Group II equipment for gas zones, Zone 1, flameproof enclosure, all gas groups (IIC), temperature class T4, equipment protection level Gb. Match this exactly to your site requirements.
From our stock: ABB and Dormot ATEX motors
Van Bodegraven supplies ATEX motors from two complementary ranges. ABB's M3JP and M3KP flameproof motors (Ex db) cover Zone 1/21 applications from 0.12 to 1000 kW. ABB M3GP (Ex ec) handles Zone 2/22. Our Dormot Pro ATEX range offers competitively priced alternatives in Zone 1 (Ex db and Ex db eb) and Zone 2 (Ex ec) including complete ATEX documentation (EU type examination certificate, declaration of conformity, instruction manual).
Most ATEX motors are not held in stock as standard, instead we build to specification based on your zone, gas group, temperature class, power, mounting and any special requirements. Typical lead time is a few weeks. For urgent cases we sometimes have like-for-like replacements available from European stock.
Frequently asked questions
Can I use an Ex ec motor in Zone 1?
No. Ex ec is only certified for Zone 2/22 where an explosive atmosphere is unlikely. For Zone 1/21 you need Ex db or Ex db eb protection. Using the wrong motor can void insurance and creates a real safety hazard.
What's the price difference between Ex db and Ex ec?
Typically Ex db motors cost 30-50% more than equivalent Ex ec models due to the heavier cast-iron construction and certified flame paths. If your zone classification allows Ex ec, this is often the most cost-effective choice.
Do I need IECEx certification alongside ATEX?
Within the EU, ATEX is legally required. IECEx is the international equivalent and is required in many non-EU jurisdictions. Most modern motors carry both certifications. Check your local regulations before specifying.
Need advice on motor selection?
Our sales engineers are happy to help you find the right motor for your application.