What is a protection class?
A degree of protection describes the design and technical measures with which a device is designed so that it can be operated safely in an explosive atmosphere without itself being a source of ignition.
The most important types of ignition protection at a glance
1. Eigensicherheit (Ex i)
With this type of protection, the energy in the circuit is limited to such an extent that no ignition can occur even in the event of a short circuit.
- Typical applications: Sensors, measurement and control technology, signal transmission
- Labeling: e.g. Ex ia
Differences by zone:
| Stufe | Area of application | Security level | Typical use |
|---|---|---|---|
| Ex ia | Zones 0, 1, 2 | Two errors are certain | Sensors in gas rooms, tank farms |
| Ex ib | Zone 1, 2 | Ein Fehler, noch sicher. | Industrial environments, process automation |
| Ex ic | Zone 2 | Only safe in normal operation | Building automation, simple monitoring systems |
💡 Praktischer Tipp: Die Eigensicherheit bezieht sich auf den gesamten Stromkreis – nicht nur auf das Feldgerät!
2. Druckfestes (Ex d) Gehäuse
Here, the device is installed in a pressure-resistant housing that can withstand an internal explosion and prevents the explosion from escaping to the outside.
- Typical application: Motors, switches, lights - but also IT components such as access points
- Labeling: e.g. Ex d
Advantages & practical knowledge:
- Devices without ATEX approval can also be operated in an Ex d enclosure
. - Example: WLAN access points in industrial environments
. - Aber Vorsicht: Es gelten bestimmte Bedingungen:
- Elektrische Parameter (z. B. Leistung, Temperaturentwicklung)
- Dimensions and thermal load
- Do not operate during operation - only open in the event of a power failure!
3. Erhöhte Sicherheit (Ex e)
Design measures are taken to avoid sparking or dangerous temperatures.
- Typical application: Junction boxes, terminals, lighting
- Labeling: e.g. Ex e
4. Druckgehäuse (Ex p)
The appliance is operated in an enclosure that is pressurized - this prevents the ingress of an explosive atmosphere.
- Typical application: Analyzers, control cabinets, label printers
- Labeling: e.g. Ex pxb
Variants:
| Variante | Zone | Description |
|---|---|---|
| px | Zones 0 | High level of protection thanks to inert gas and flushing |
| py | Zone 1 | Medium protection, limited irrigation |
| pz | Zone 2 | Simple protection, often with ambient air instead of shielding gas |
✅ Fazit: In vielen Geräten – wie beispielsweise Etikettendruckern – reicht Überdruck mit Umgebungsluft aus. Schutzgas ist nicht unbedingt erforderlich!
5. Verkapselung (Ex m)
The components are encapsulated in non-conductive material so that no ignition source can escape.
- Typical applications: Sensors, electronic modules - but also portable devices!
- Labeling: e.g. Ex mb
Criticism in practice:
- Unfortunately, it is also used for mobile devices.
- Reparaturen sind kaum möglich:
- Defekte Buchse oder Display = Totalschaden
- No interchangeability of individual components
- Particularly annoying with expensive ex-smartphones or handheld scanners
6. Ölbad (Ex o)
The ignition sources are located in an oil bath that shields heat and sparks.
- Typical application: transformers, switchgear
- Labeling: e.g. Ex o
7. Sandverkapselung (Ex q)
Ignitable parts are completely embedded in fine-grained quartz sand to safely absorb heat and sparks.
- Typical applications: Capacitors, resistors - and even portable devices!
- Labeling: e.g. Ex q
Conclusion
Selecting the right type of protection is not just a formality, but crucial for safe and economical operation. Whether intrinsic safety, flameproof enclosure or pressurization - each method has its strengths and limitations.
🔍 Unser Tipp: Achten Sie darauf, dass Ihr Gerät leicht repariert werden kann, insbesondere wenn es mobil ist. Wir von ATEXshop.de helfen Ihnen gerne weiter!