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Nema 4x in hazardous class 2 environment?

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I was told that you can put a nema 4x enclosure in a hazardous environment class 2 as long as you pressurize it.  Can anyone confirm?  Thanks!

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What division? Div 1 or Div 2, class 2? Actually, you can use a NEMA 12 enclosure, if you use a purged or pressurized system in Div 2, class 2.

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Chris is absolutly correct. What division? Div 1 or Div 2, class 2? Also, using a NEMA 4, 4x or a NEMA 12 enclosure really depends on the environment and not so much on the class or div 1 or 2. (outdoor, Indoor wet or Dry, Caustic, etc). You can add purging, Air conditioners for hazardous locations, etc to reduce the class and division to an acceptable level while maintaining a suitible environment for electronic components inside an enclosure.  ALarm contacts from the air handling equipment are incorporated into the system to notify a remote operator, activate an audible or visual alarm, and / or shut down the system in an organized mannor if necessary. A very good source of products AND information for this issue is : Bebco Industries Bebco Industries 600 Gulf Freeway Texas City, Texas 77591 Phone: (409) 935-5743 Fax: (409) 938-4189 I am not associated with this company, however it has helped me many times over the years. It helps to talk to a representative of the company. They will help you to define all the parts required for installation of the equipment saving you time and last minute headaches in the manufacturing process, (I speak from experience!)    , and they're quick to get you a quotation. They have all the information you should need in there catalogue as well as a CD ROM you may request. I hope this helps, Scott Davies   sldavies1@hotmail.com

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Sorry for the newbee question and thanks for the help!    It's a Division 2 evironment.  I have a 4X chart recorder that needs to be mounted on an enclosure.  I was told to pressurize the enclosure and use ss 4x because of the enviroment.  I wasn't sure if I'd need Nema 9 instead.  Because the operator will need to change the chart everyday, will opening the chart recorder window (no longer 4x and access into the chart recorder internal components) make the system more dangerous?    Can I bring 120VAC to power this chart recorder?  

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The use of the proper purging system will reduce the enclosure (internal) rating from Class 2, Div 2 to a non-hazardous rating. This is only as long as the enclosure remains sealed and the appropriate amount of pressurization is applied ----continuously----AND ----for a minimum period of time. What this means is this: The enclosure, no matter what the NEMA rating, 12, 4X, etc. will be open when installed and periodically serviced or accessed for what ever purpose, in the area of which hazardous gases are present. During this period of time the enclosure MUST be de-energized, power completely removed from the enclosure. The reason....the enclosure becomes a hazardous, explosive environment. To re-energize the enclosure it must be resealed and purged with clean air for a minimum period of time (depending on the size of the enclosure and the exchange rate of the purging system). ONLY after this minimum period of time has passed under these conditions may the enclosure be re-energized. Pay particular attention to the explosive seal requirements for all conduit and cable entries. Also Interlocks and proper labeling of all enclosures is required and observance of proper lockout-tagout procedures is a must. This condition applies to all enclosures INCLUDING the chart recorder. NOTE: The chart recorder may require purging also if it is in a sealed enclosure even though mounted through the NEMA 4X enclosure. There are exceptions to this such as if the environment has been tested and proven to be free of hazardous gases during the time of service. However I prefer always to err on the side of safety. Please refer to the site I previously mentioned if only for information and education on the subject and if the chart recorder must be accessed on a daily basis, while the system is energized, it would probably be best to mount this remotely in a clean and safe environment such as a control room. I hope this helps. I am not an expert on this subject, by any means. I've just done this a dozen time or so. Please spend a few hours or a day studying this subject and talk to an expert at the link I gave you or a similar company. He or she may be able to enlighten you on the subject of the chart recorder. It will pay off in your short and long term efforts. Good Luck! Scott

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Thanks for all the help, Chris and Scott.  Much appreciated.  I will read up on the website you mentions. Thanks again!

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