Ex-pert Electrical Technologies

Dynamic elaboration on the Art & Science of Hazardous Area Protection

Optical Radiation Hazard

Optical Radiation : Ignition Risk & protection in Hazardous Areas   The industrial use of equipment, utilizing OPTICAL RADIATION , is increasing day-by-day. The most common use is in the fields of … Continue reading

April 22, 2014

Ex Terminology

 Ex Terminology Class  ( locations) Creepage & Clearance Equipment Protection Level EPL Explosion Explosive Atmosphere Explosive Gas Atmosphere Explosive Dust Atmosphere  Explosive Limits (upper & Lower Explosive) Flammable Substance Flash point … Continue reading

March 15, 2014

Minimum Ignition Current (Ratio)

Minimum Ignition Current  ratio The minimum current required from an inductive spark discharge to ignite the MOST EASILY IGNITABLE MIXTURE of a GAS, MIST or DUST in air …..relative to … Continue reading

March 5, 2014

Glance: Ex Art

Ex Art  (The, almost, hidden side of Hazardous Area protection) More …at Ex-Art

February 2, 2014

Ex Components

What is an Ex Component ? Definition : An Ex component is  a part of electrical equipment or a module , marked with the symbol U, which is not intended … Continue reading

December 24, 2013


A personal view about Hazardous Area Codes Making , Specification , Testing & Certifying process The DIRECTIVE 94/9/EC has been replaced by a new DIRECTIVE 2014/34/EU. The old directive was … Continue reading

November 14, 2013

Selection of Electrical Equipment

Selection of Electrical Equipment for Hazardous Area Outline of procedure , in following simplified form , for selection of  electrical equipment for installation in hazardous Area. The procedure is being presented … Continue reading

October 17, 2013

Equipment Protection Level

Equipment Protection Level (EPL) Its a Concept. This is a part of risk assessment method It has been introduced to enable an alternate approach to current methods of selecting Ex … Continue reading

September 16, 2013

Ex & Degrees of Protection (IP) According to IEC 60529

Ex & degrees of Protection (IP) according to IEC 60529 in comparison to NEMA Enclosure-Types. A system for classifying the degrees of protection provided by the enclosures of Electrical Equipment … Continue reading

July 17, 2013

Condensation of Water & Breather Gland

Condensation is a natural process by which the physical state of the matter is changed from GASEOUS STATE into LIQUID STATE. This process is opposite to that of VAPORIZATION. In this … Continue reading

July 13, 2013

Maximum Experimental Safe Gap

Maximum Experimental Safe Gap (MESG) Definition: (Ref: IEC 60079-1 ) Maximum Experimental Safe Gap (for an explosive mixture ) of a joint 25mm in width which prevents any transmission of … Continue reading

May 15, 2013

DUST Groups

  Electrical Equipment for Group III (DUST) Electrical Equipment for use in explosive Atmospheres are divided according to the following types of explosive atmospheres (To facilitate the procedure of selection … Continue reading

May 8, 2013

[Associated Apparatus]

[Associated Apparatus] Power Reduction philosophy  for Intrinsically Safe devices operating in  Explosive Atmosphere References IEC 60079-Part 0: Equipment – General requirements IEC 60079-25: Explosive atmospheres – Part 25: Intrinsically safe … Continue reading

April 27, 2013

Documentation & Certifications

  IEC 60079-14 gives us an over-view of the necessity & importance of the process of documentations for Hazardous Area Installations. By documentation we mean the material in Printed or … Continue reading

January 1, 2013


A haunting question. Is it a dilemma  or a  complete solution ….does it require the NEC-IEC vision… Let us see… We will use the following picture as a symbolic representation … Continue reading

December 10, 2012

IEC Time Line

The time-line of Hazardous Area Protection Domain Safety Lamp by Sir Humphrey Davey, coal mines and the time-line of Hazardous Area Protection Techniques Coal is a source of energy. The … Continue reading

November 6, 2012

Ex (As per ATEX Directives)

Ex (As per ATEX Directives) This Hexagon Logo with “Ex” marked inside is as per specification of ATEX ( ATmosphères EXplosives ) . This mark along with the EC mark, … Continue reading

October 29, 2012

Zone II

Reference Documents: 60079-15   (Equipment protection by type of protection ‘n’) SCOPE: IEC 60079-15 is applicable to: Non-sparking electrical equipment Equipment having parts or circuits producing arcs or sparks Equipment  … Continue reading

October 29, 2012

The Fire Triangle & The Dust Explosion Pentagon , The Fire Diamond

The “Fire Triangle” is a graphic representation of a concept, used to list the following prerequisites of an explosion:- FUEL  (Flammable Material in form of GAS or Vapors ) Oxygen from the air … Continue reading

October 29, 2012

The Safety Lamp

 THE BEACON OF SAFETY       A short  trip down the History Lane . Safety lamp for coal mines is a special lamp that provides illumination, using a small … Continue reading

October 28, 2012

To use..or NOT to use ..Conduit-Hub or Cable-Gland

NEC Art Gallery CONDUIT HUBS Conduit Hubs are used to terminate the conduits into an enclosure . Hub is installed, through a drilled hole into the certified enclosure and fastened … Continue reading

October 28, 2012

To Use… or NOT to use.. Conduits or Cables

Conduit or Cable for Ex d or Ex de Enclosures  The term ‘Conduits’ refer to the use of Ex-certified metallic pipes to house the insulated electrical wires for transfer of electrical … Continue reading

October 28, 2012