Hello!

What is the significance of an Ex(e) JB/panel as compared to a standard non certified JB/panel? What type of apparatus can be installed in an
Ex(e) JB/panel?


Bye!
Omer

 

Hello!

An Ex junction box is suitable for a hazardous environment. The junction box is built to withstand and contain an explosion within the box. Typically you would install devices inside the junction box that are not suitable to be placed directly in the hazardous location.

 

Omer,

Ex e stands for "Increased Safety". The method of protection works by taking extra measures with electrical components to make sure there are no sparks or hot-spots developed in normal operation or under fault conditions. The total power dissipated in a JB is also restricted, to keep the temperature rise to a safe level.

Any Ex e enclosure must have an IP (Ingress Protection) rating of IP54 or better.

All terminals used for Ex e equipment must comply with requirements for cable clamping, security of alignment, and creepage and clearance distances. Terminals will also be rated as Ex e.

One manufacturer who makes available a lot of information is Weidmuller http://www.weidmuller.co.uk

Bruce

 

Hi,

EEx(e) protection is increased safety.

Usually junction boxes (having only terminals) without electronic parts that can cause a spark can be used. For EExe junction box one can use EExe cable glands (some manufacturers have same glands for EExe and EExd applications (they are all EExd).

Other application is a combined equipment:

Electrical actuator ( EExde)

It means that the Electric Motor is in EExd compartment, insulator with wires leads to the Exe part of the compartment where the terminals are located.

You can ask why to use it?

Reason for it is that in case of using EExd unit the cable glands shall be EExd, and the cable shall be applicable for the Cable gland (The sealing shall be on Outer sheet and Inner sheet ).

In case of Exe terminal enclosure, the gland can be Exe and the cable can be sealed only on outer sheet.

Hope I helped

Zelenka

 

This statement is not correct. "EX" is the IEC prefix designator for a hazardous area method of protection for Zone areas of which flameproof(explosion-proof) as described above is only one. The box in discussion, EX(e) which I assume is the EX "e" protection method, stands for "increased safety." EX "d" is the designation of a flameproof(explosion-proof) box which is designed to contain an explosion, maintain any the surface temperature to a safe level, and safely vent any hot gasses.

This web site( http://www.hazloc.com/index-noframes.html ) has a description of the types of protection for Zone areas(as well as being a good source for other hazardous area stuff) including this detailed description for increased safety:

"Increased safety "e": Type of protection applied to electrical apparatus that does not produce arcs or sparks in normal service, in which additional measures are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks."

Bill Mostia
===========================================================
William(Bill) L. Mostia, Jr. P.E.
Partner
exida.com, LLC
Excellence in Dependable Automation
wmostia(AT)exida.com(b)
www.exida.com 281-334-3169
These opinions are my own and are offered on the basis of Caveat Emptor.

 

I think there is a bit of confusion here between North American practice and that in the rest of the world. In the IEC system, "Ex e" is a specific designation that indicates that equipment is built to the requirements of the Increased Safety method of protection. With this, the design is such as to ensure there is a negligible chance of arcing, sparking, or overheating causing ignition of flammable material within an enclosure.

Equipment which is capable of withstanding an internal explosion is designated as Ex d or flameproof. Here no particular precautions are taken to prevent ignition within the enclosure, but the hot gases and other effects of the explosion are confined to the interior of the enclosure and cannot cause ignition of the surrounding atmosphere.

Bruce

 

Hi,

It is necessary to say that in fact, "an Ex junction box is suitable for a hazardous environment". But Ex-e is the IEC type for use where no arcs, sparks or other sources of ignitions are present inside the enclosure. To withstand an internal explosion, only Ex-d type (flameproof) is allowed.