Junction Box Clarification

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SArsalan Associate Join Date: Jan 2013 Posts: 40	Junction Box Clarification 09/05/2013 2:39 AM
	Hi I have to provide a junction box to client for termination of I.S circuits. The client requirement is to provide an Exe certified box. The vendor specifications state Execution: Ex-ia IIC T6 As per my understanding Ex-ia certification is for instruments and not enclosures. So this JB must be suitable for installation of Ex-ia equipment. May be?? or does this mean something else?
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	Pathfinder Tags: enclosures Exe junction box

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PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#1 Re: Junction Box Clertification 09/05/2013 3:22 AM
	If the circuits have been installed correctly to EEx ia then the matter of the certification of the junction box is irrelevant and superfluous. So if the Client wants an EEx e junction box, let the Client pay for it. __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
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SArsalan Associate Join Date: Jan 2013 Posts: 40	#2 In reply to #1 Re: Junction Box Clertification 09/05/2013 4:32 AM
	Obviously the client will pay but i asked the question for my understanding: What is the difference between Exe and Exia and can both of these be applied to enclosures like junction boxes. According to http://en.wikipedia.org/wiki/Electrical_equipment_in_hazardous_areas Ex-ia is for instruments and Ex-e applies to junction boxes. So when my Junction Box vendor says Ex-ia for the junction box is he wrong?
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PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#3 In reply to #2 Re: Junction Box Clertification 09/05/2013 5:35 AM
	Yes, of course. EEx ia is a method of preventing explosion in Zones 0, 1 and 2 and relates to the restriction of the energy in the circuit below that which is capable of causing ignition with two faults applied to the circuit. It is not possible to apply the concept to a junction box. EEx e is a method of preventing explosion in Zone 1 and 2 by generally increasing the standard of the junction box, its fittings, and the way it is installed and used. Putting an EEx e junction box on EEx ia circuits is overkill. Though if the Client wants to pay for it, let the Client pay for it, and waltz off rejoicing. However, asking the question here suggests a shortfall in the training received to date on correct practices for installing electrical equipment in hazardous areas. Stopping work and attending appropriate training without delay would be highly recommended in that circumstance. __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
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SArsalan Associate Join Date: Jan 2013 Posts: 40	#4 In reply to #3 Re: Junction Box Clertification 09/05/2013 8:01 AM
	Thanks for the answer. For the training part i agree as i am new in the field but i mostly work with safe areas. However i was not involved in the FEED design and Hazop etc and ppl who finalized the zones and marked hazardous areas were knowledgeable enough and must have done it right (so no worries there). I just had to get the JBs approved from the client. I just wanted to improve my understanding and thanks to guys like you willing to share knowledge; having learnt something new i will sleep well tonight .
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PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#5 In reply to #4 Re: Junction Box Clertification 09/05/2013 8:41 AM
	It is important to have design passed through a second person with relevant technical knowledge prior to "approval for construction". Make sure this happens as part of the training. It is important. __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
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