Dear Brian,
A number of standards exist which describe the constructional and test requirements of electrical apparatus for use in potentially explosive atmospheres. The applicable standards would depend on the intended country of use. The following tables gives a list of the applicable standards for electrical equipment for use in Zone 1. Intrinsically Safe equipment could be used in Zone 0 which is the highest risk. Type of Protection Europe USA IEC General Requirements EN50014 ANSI/ISA S12.0.01(IEC79-0 Mod) IEC 60079-0 Flameproof EN50018 ANSI/ISA S12.22.01(IEC79-1 Mod) IEC 60079-1 Pressurized Enclosures EN50016 IEC 60079-2 Powder Filling EN50017 ANSI/ISA S12.25.01(IEC79-5 Mod) IEC 60079-5 Oil Immersion EN50015 ANSI/ISA S12.26.01(IEC79-6 Mod) IEC 60079-6 Increased Safety EN50019 ANSI/ISA S12.16.01(IEC79-7 Mod) IEC 60079-7 Intrinsic Safety EN50020 ANSI/UL 913 IEC 60079-11 Encapsulation EN50028 ANSI/ISA S12.23.01(IEC79-18 Mod) IEC 60079-18 In the USA the National Electrical Code Article 500 allows the use of either Zone or Division Classification, but the number of types of protection is not as varied, being limited to Intrinsic safety [ANSI/UL 913] Explosionproof [ANSI/UL1203] Purged and Pressurised [NFPA496]. ANSI standards based on IEC60079-11, and IEC60079-2 are currently under development. In all of the above cases certification by a Notified Body in Europe and a NRTL in the USA are required. A lower level of risk [Zone 2 or Division 2] also exists, and this may be self certified in some countries. In the US the standard to use is ANSI/ISA S12.12, in Europe EN50021 and the IEC standard is IEC60079-15. If you have any questions please do not hesitate to contact me directly. Nicholas Ludlam Factory Mutual Research Tel: (781) 255 4847 Fax: (781) 762 9375 -----Original Message----- From: Brian At Work [mailto:[email protected]] Sent: Wednesday, July 28, 1999 11:49 AM To: IEEE Group Subject: Flamible Liquids and Vapors Hello Group, Our company is working on a small laboratory device, about the size of a computer tower, that contains, in addition to electronic components, about 1 gallon (3.8 liter) of a solvent chemical. The solvent can be one or a combination of several different chemicals such as acetone, methanol, ethanol, etc.. These chemicals and/or vapors are flammable and could possibly cause a fire or explosion under the right conditions. Protection against the ignition or explosion of a flammable liquid is not directly covered in the EN61010 safety standard (or not as I have found). Is there another standard that addresses these requirements more specifically? Does anyone with experience in this area have some advice or a summary of requirements they could give me? Thank you for your time, Brian Kunde --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
