Can the UPS power supply of the SIS system be shared with the DCS system?
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A few days ago, **experts were organized to conduct an inspection of our company, and a potential hazard was identified: the SIS and DCS systems do not have separate uninterruptible power supplies.** (Our company’s DCS and SIS systems share one UPS supply, with an additional power supply from the mains; the distribution panels for these two systems are separate.) By referring to the \"Design Specifications for Instrument Power Supply\" (HG/T 20509-2014), the \"Design Specifications for Instrument Power Supply in Petrochemical Industries\" (SH/T 3082-2003), and the \"Guidelines for Identifying and Addressing Hazards in Hazardous Chemical Enterprises\" (An Jian Zong Guan San [2012] No. 103), the inspection forms related to instrument hazards only mention the need for a UPS supply, without specifying the need for separate UPS supplies for each system. I would like to ask everyone: Are there any other regulations or **government mandates that stipulate that chemical plant SIS and DCS systems must be equipped with separate uninterruptible power supplies?
According to Clause 5.0.16 of the \"Code for Design of Safety Instrumented Systems in Petrochemical Industries\" (GB/T 50770 - 2013), the AC power supply for safety instrumented systems should preferably come from a dual-channel uninterruptible power supply system. Explanation of the provision: 5.0.16 The safety instrumented systems of large-scale petrochemical production units shall employ dual independent uninterruptible power supplies. Interpretation by the State Administration of Work Safety: \"Criteria for Identifying Major Potential Hazards in Production Safety Incidents in Chemical and Hazardous Chemicals Production and Operation Units\" – \"14. Chemical production facilities do not have dual power supply systems as required by ** standards, and their automation control systems lack uninterruptible power supplies.\" The main purpose of this clause is to enhance the safety of critical loads and control systems in chemical processing plants from a hardware perspective, by providing dual power supplies for these plants and uninterruptible power supplies for their automated control systems. The relevant standards mainly include the \"Code for Design of Power Supply and Distribution Systems\" (GB50052-2009) and the \"Technical Specifications for Electrical Design of Production Units in Petrochemical Enterprises\" (SH3038-2000). For example, on February 21, 2017, an explosion occurred in a reactor at the ***amine production workshop of Lixin Chemical Industry Company in Alxa League, Inner Mongolia, resulting in 2 deaths and 4 injuries. Upon investigation, it was found that the accident-stricken company resumed operations without having adequate emergency power supplies. Due to a heavy snowfall, the entire industrial park lost power, and the company’s emergency power supplies became unusable; as a result, the reaction vessels in the ***amine production workshop could not be cooled, leading to an explosion. ” Chemical enterprises are required to have dual power supplies, and their automation control systems must be equipped with uninterruptible power supplies. As for the requirement that \"the SIS and DCS systems of the plant should be equipped with separate uninterruptible power supplies,\" you can consult experts to find out what the basis for this requirement is If the cost of making corrections is not high, carry out the corrections according to the experts’ advice.
Ask the expert to provide evidence. . The threshold for becoming an expert these days is too low.
The last edit to this post was made by fpiliuwei on 2019-6-14 at 13:41. If the UPS systems for SIS and DCS are to be separate, does that mean the power supply for these UPS systems also needs to be separate, coming from different main transformers? The development of standards should take into account technical feasibility while also being practical. The scope of application of these standards is broad; they should not be arbitrarily elevated to the point where practical implementation becomes impossible. Who said that DCS and SIS must each be powered by separate UPS systems? Ask him to provide the name of an actual project, and say you want to *learn from it*.
The expert’s suggestion is incorrect, but your company’s approach is also wrong. SIS needs two sets of UPS
Of course, since these are existing projects, this can be mentioned to the experts; it is advisable to follow the standards, but it’s not absolutely necessary to have two sets
It definitely can’t be right. What is SIS? The SIS must have two sets of independent UPS units that serve as a redundancy for each other. Just the SIS itself requires two sets. You also share one set with DCS.
After calculation, if the capacity of your UPS is sufficient to cover the load plus that of the SIS, then there is no problem and they can be used together. The premise is that this is not a large-scale petrochemical production facility. Of course, if there is space, it would be better to install a separate UPS for the SIS. If the SIS has few points, the UPS capacity will not be large either, so it will be less expensive. It’s better to avoid arguing with experts: lol
Based on what? What is the basis for your claim?