The basics of explosion protection - STAHL - #33

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Class I, II & III, Division 1 and 2 The approved electrical equipment for Class I, Class II and Class III, Division 1 and Division 2 must be marked to show the following information: 1. Class(es), Division(s) (optional except for Division 2)2. Gas/dust group(s) 3. Operating temperature or temperature class(optional T5 and T6)Example: Class I Division 1 Groups C D T4 33 (2) Zone EquipmentEquipment meeting one or more types of protection described in Article 505 of the NEC or Section 18 of the CEC shall be marked with the following in the order shown: 1. Class (optional in Canada) 2. Zone (optional in Canada) 3. AEx (USA) or Ex or EEx (Canada) 4. Type(s) of protection 5.Equipment group II or applicable gas group(s)IIA, IIB or IIC6. Temperature class Example: Class I Zone 0 AEx ia IIC T6 6.6 Certification and Marking Class I, Zone 0, 1 and 2 For equipment intended for use in Class I, Zone 0, Zone 1 or Zone 2, a distinction is made between “Division Equipment” and “Zone Equipment”. In the USA and Canada, electrical apparatus andapparatus used in hazardous locations are, as a rule, subject to approval. Exceptions to this are items of electrical apparatus which, due to their design and the peculiar nature of the explosive atmosphere in which they are used, cannot ignite. The responsible authorities shall decide whether such equipment is subject to approval.Equipment which has been developed and manufactured for use in hazardous locations is tested and approved in the USA and Canada by a notified testing authority. In the USA, this is for example the Underwriters Laboratories or Factory Mutual, and in Canada the Canadian Standards Association.In addition to data such as manufacturer, type,serial number, and electrical data, any data relat- ing to explosion protection must be shown on the marking of the equipment.The requirements for this are specified in the NEC, the CEC as well as the relevant apparatus regulations of the testing authority. (1) Division EquipmentEquipment approved for Class I, Division 1 and/or Class I, Division 2 shall be permitted to be marked with the following: 1. Class I, Zone 1 or Class I, Zone 2 2. Gas group(s) IIA, IIB or IIC 3. Temperature class 4. Types of Protection Example: Class I Zone 1 d,e IIC T4
R.STAHL explosion protection