Ex o Oil Immersion | Explosive Atmospheres & Explosion Proof Protection Concepts

ex o oil immersion

Ex o or Oil Immersion is a type of explosion protection applied to electrical apparatus such that, all internal parts that are capable of igniting a flammable atmosphere are completely immersed in oil so they cannot come into contact with flammable atmospheres in hazardous area zone locations.

Equipment using this Oil Immersion explosion protection method is marked as Ex o and suitable for use in both Zone 1 and Zone 2 hazardous areas.

The basic principle is to immerse the electrical parts in mineral oil, which will prevent any exposure of the arcing or sparking to an explosive atmosphere. It will also quench arcs and limit the temperature rise on electrical parts.

Standards for oil immersion protection, Ex‐o, require that all parts capable of producing arcs or sparks must be immersed in the oil at a set depth based on the working voltage of the equipment.

All hazardous area located equipment that has the potential to arc and potentially cause an ignition is immersed in a protective liquid or oil – the oil provides an insulating method to prevent ignition.

TYPE OF PROTECTION TO ELECTRICAL EQUIPMENT

Type of Explosion Protection	Oil immersion Ex o – EN IEC 60079-6
Explosion Protection Principles	Protection principle prevents the potentially explosive atmosphere reaching the ignition source
Flammable Material	Gas/vapour (G)
Category 1 EPL a – Very High Level of Explosion Protection	–
Category 2 EPL b – High Level of Explosion Protection	Ex ob Explosion Protection
Category 3 EPL c – Normal Level of Explosion Protection	Ex oc Explosion Protection

oil immersion ex o, ex ob, ex oc

Principle
Parts which might ignite an explosive atmosphere are immersed in oil or other non-flammable, insulating liquid so that gases and vapours above the oil level and outside the enclosure cannot be ignited by electric arcs or sparks generated below the oil level, or by hot residual gases from the switching process or by hot surfaces – e. g. on a resistor

Important Design Parameters

Stipulated, insulating liquids, e. g. oil
Protection of the liquid from contamination and moisture
Non-electrical equipment
– Liquids
– Wet surfaces
Assurance and possibility of monitoring that the oil level is safe
– When heated up or cooled
– For identification of leaks
Restricted to non-portable equipment

Ex o Explosion Protection Applications

Large transformers, switchgear, starting resistors and complete starting controllers
Gear

Explosive Atmospheres &

Explosion Protection Concepts

💡 Thorne & Derrick, Specialist Suppliers & Stockists of Electrical and Process Instrumentation Equipment for installation in hazardous area location can assist with your project requirements. Know your Ex Concepts:

For further technical information see | Hazardous Area Zones | Explosive Atmospheres | T Class Ratings

ELECTRICAL & PROCESS INSTRUMENTATION EQUIPMENT

FOR EXPLOSIVE ATMOSPHERES

Ex o Oil Immersion Equipment

Thorne & Derrick are Specialist Distributors of Hazardous Area & Explosion Proof Equipment with IECEx & ATEX Certifications to the onshore and offshore oil, gas, petrochemicals and process industries.