Power supply issue for the CPU module of DCS
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The CPU module is powered by dual power supplies; it can be powered by both supplies simultaneously, with each supply being used in full, or the load can be distributed between them, such as using half of the capacity from one supply or allocating it based on percentages. When one of the circuits loses power, the other automatically takes on all the load – I didn’t know anything about this; it overturned my understanding. I racked my brains and couldn’t sleep at night, and my boss was waiting for my response. What should I say? If any of the experts out there know something, please give some advice.
Your question? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Same question: Let’s study*study*
In this case, it is not usually the CPU module itself that distributes the load; rather, a redundant power supply switching technique is used: 1. The CPU module typically has only one actual DC power supply input, but there are two power supply modules (or two power supply channels) provided externally. 2. The two power supply modules achieve load sharing or automatic switching through diodes or the ORing circuit (redundant module) built into the power modules. - Under normal conditions, the two power supplies can operate simultaneously, with the current being distributed evenly according to the load characteristics; for example, 50% on each supply, or any other proportion is possible. - Once one of the circuits fails or loses power, the output voltage of the other functioning circuit becomes slightly higher, causing the current to be carried entirely by that functioning circuit, thereby achieving a \"seamless\" automatic switchover. 3. This approach is common in PLC and DCS systems, with the aim of achieving power supply redundancy to ensure that the operation of the system is not affected in the event of a failure of a single power source. In summary, the response to the leader could be phrased as follows: “It has been understood that the CPU module of the DCS does not actively allocate power percentages; rather, it is the two redundant power supplies that automatically share the power through an external redundant switching circuit.” When one power supply fails, the other takes over all the loads immediately. This design is widely used in the field of industrial control; it is not a novel technology, so there is no need to worry. ” .
This post was last edited by feng*aosa on 2025-7-10 15:09. Isn’t it just dual power supplies connected in parallel?
I remember that Mean Well power supplies seem to be available
Some experts do not acknowledge this redundant power supply mode. A dual-power supply should have two power supplies entering the cabinet. Modules with redundant automatic switching can still fail.