Should combustible gas and toxic gas detection systems be powered by a UPS?
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SH/T3082-2003 states that combustible gas and toxic gas detection systems should be powered by a UPS. What do you all think? Is it necessary to use UPS power supply? As far as I know, some devices are not powered by UPS on-site.
Clause 5.3.1 of the HGT 20509 Instrument Power Supply Design Specification: In the following situations, a UPS should be used for instrument power supply: 1. Production units that utilize DCS, FCS, or SIS; 2. CCS； 3. Online analyzers used for interlocking and process control; 4. Detection and alarm systems for flammable and toxic gases
Guidelines for word usage: Terms indicating strict requirements, which should be followed under normal circumstances: for positive terms, use “should”; for negative terms, use “should not” or “shall not”.
Flammable and toxic gases require separate detection systems, and such systems should be powered by UPS; however, our facility doesn’t have one
For toxic gas detectors and combustible gas detector cabinets, reputable manufacturers usually integrate a small UPS power supply within the cabinet. If this is not possible, it is also acceptable to connect the detector cabinet directly to the UPS output of the DCS system. In the case of wall-mounted detector boxes that are located far away from the UPS, it really doesn’t matter; after all, the actual circumstances must be taken into consideration. In our factory, aside from the alarm panels in the workshop control rooms that are not powered by UPS, all the large alarm cabinets in the DCS system are equipped with dual power supplies.
You still need to follow the standards, but even if you don’t use a UPS, they won’t know anyway
Each standard includes an explanation of certain qualifiers; “should” means it is necessary, and it must be present in most cases unless there are special circumstances. Therefore, it is recommended to add a UPS
In the design process, design institutes will certainly consider using UPS to supply power to flammable and toxic gases; as for how this will be implemented in practice, it depends on the actual construction work