How to use the interlock button
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The newly installed unit is equipped with interlocks. If the unit loses power, how should these interlocks be used? Please refer to the diagram. Thank you; points will be given
Since the device has lost power, it must have stopped working as well; then why press the buttons? It’s confusing
A power outage in the grid will cause the entire plant to shut down, but basically, large-scale installations rarely experience such outages over many years
Major power outages are rare; usually, a dual-power supply setup is used, right?
When you say there’s a power outage, do you mean a outage of the mains power or an outage of both power supplies?
In the event of a power outage, the interlock will operate automatically according to the settings; manual intervention is generally not required! The manual emergency stop button is used in situations where special circumstances arise that do not trigger interlocks, but an automatic shutdown is still required; for example, in the event of a fire in a certain part of the equipment. The reset buttons are used to confirm the conditions and to perform a reset
In the case of a normal power outage, it is sufficient to disconnect the interlock from the DCS. In the event of a sudden power outage, accidents may occur; therefore chain protection is required – open the protective cover for the manual emergency stop and press the button (press it carefully) ( )
Safety interlock for emergency stop? It is required to use the SIS system, and this system falls under the category of particularly important loads among primary loads; therefore, it is usually powered by a UPS. The UPS must be able to supply power to the connected loads for half an hour. So, even if there is a power outage, the safety interlocks will not be affected – you can simply press the buttons, as there will be no power shortage
Emergency stop buttons are generally dry contacts connected to the control system, which is powered by a UPS; thus, a power outage in the mains does not affect it. If the UPS loses power, the entire system is in a faulty state; the physical devices are also in a faulty state or remain in that state, and the emergency stop button becomes meaningless.