Safety Switches with Metal Housing - EUCHNER GmbH + Co. KG - #5

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General Subject to technical modifications; no responsibility is accepted for the accuracy of this information. 5 Standards and approvals Standards Safety switches must meet the requirements for safety components as per the Machinery Directive. The Machinery Directive has been implemented in national law in the EU member states and, as a result, is binding for all manufacturers. Detailed requirements for the switches are defined in EN 60947 Part 5-1 (Specification for low-voltage switchgear and controlgear. Part 5-1: Control circuit devices and switching elements. Electromechanical control circuit devices). If the requirements of this standard are met, conformity with the applicable laws and therefore with the Machinery Directive is assumed. EUCHNER safety switches comply with the relevant standards for safety switchgear and therefore help you to comply with safety requirements during the design of your machinery. Approvals To demonstrate conformity, the Machinery Directive also includes the possibility of type examination. Although all relevant standards are taken into account during development, we have all our safety switches subjected to additional type examinations by a notified body. Many of the safety switches listed in this catalog have been tested by the German Social Accident Insurance association (DGUV), formerly the employers’ liability insurance association (BG), and are given in the lists from the DGUV. Furthermore, numerous switches are listed by Underwriters Laboratories (UL). These switches can be used in countries in which this listing is required. The approval symbols on the individual pages of the catalog indicate which body tested the switches. With the aid of the approval symbols listed below you can quickly see which approvals are available for the related switches: Function and technology used in safety switches The task of safety switches Safety switches have the task of preventing the operation of a machine in the case of a potential hazard. This task is defined in EN 1088 (Safety of machinery. Interlocking devices associated with guards. Principles for design and selection). For this purpose the safety circuit must be opened by the safety switch. Safety switches are therefore key elements of an interlocking device. In this context an interlocking device is, for example, the interruption of machine operation if the safety door is open – the stop state of the machine is ”interlocked” so to speak and unintentional starting is therefore prevented. In relation to movable safety guards this means that if safety doors or safety flaps are open, the machine or system cannot be operated if the machine or system can produce a hazard. For this reason the safety switch for a safety guard must be attached such that a malfunction is excluded. Safety switches must also not be tampered with or bypassed. The most important feature of a safety switch is at least one NC contact which is operated positively. The switching contacts are separated by a positively driven mechanism when the safety guard is opened. Safety switch types In general, a differentiation is made between safety switches with safety function and safety switches with separate actuator. EUCHNER has safety switches with safety function and safety switches with separate actuator in its range. Safety switches with safety function Safety switches with safety function are safety switches in which the actuating element and the switch are fitted in one housing. The actuating elements are available in various versions (e.g. in the form of a plunger or a lever arm). The switches N1A, NB01 and NZ listed in this catalog are safety switches with safety function. To actuate a switch with safety function, trip dogs or cams are often used (see figure on the next page). The switch must be attached such that the switch is actuated if the safety guard is opened. The positively driven contact in the switching element is opened and the machine is shut down. A built-in spring returns the switch to the free position when the safety guard is closed and the positively driven contact is closed. In this way the safety circuit is enabled again. A safety trip dog with a defined slope should be used to approach the switch. Linear trip dogs are generally used for travel limiting or for shutting down in final positions. A cam with cut-out (negative dog) is particularly suitable for protecting safety guards. An alternative is the safety hinge ESH. With safety function With separate actuator Special approvals: Switches with this symbol are approved by the Germanischer Lloyd (GL) Switches with this symbol are in accordance with the governmental russian standard ÃOCT (GOST) Switches with this symbol are approved by Underwriters Laboratories (UL, Canada and USA) Switches with this symbol have the approval of the German Social Accident Insurance association (DGUV) – formerly the employers’ liability insurance association (BG)