| 摘要 |
The invention relates to a safety device for an industrial boiler (CHA) comprising electromechanical relays (REn, RS), which are connected in series in order to form an electromechanical safety chain (CH1), and at least one shunt relay (RTn) which is normally open and mounted in parallel to one of the electromechanical relays (REn). Said shunt relay is controlled by an automaton (API) so that it is closed during a time delay. According to the invention, the shunt relay (RTn) is provided with a contact that is connected to an electronic circuit (CEn) and said electronic circuit (CEn) opens an electromechanical relay (RS) which is mounted in series in the safety chain when the shunt relay (RTn) is closed for longer than the time delay. Given said arrangement, in the event of an automaton failure, the time delay is ensured by the electronic circuit so that a satisfactory level of safety is guaranteed in relation to the installation.
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