HG/T 20509-2014 Code for Design of Instrument Power Supply

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====Load classification: ==== 【I】Class 1 load: A load is classified as a Class 1 load when a power outage would result in personal injury, OR significant economic losses, OR disrupt the normal operations of {important} facilities. 1.1 Among first-class loads, those whose power interruption can lead to casualties, severe damage to equipment, poisoning, explosions, fires, etc., AND those that are particularly important and must not experience power outages, should be regarded as [particularly important first-class loads]. 【II】Class II load: 1. A power outage will result in {significant} economic losses, OR when {important} organizations are operating normally, such loads are classified as Class II loads. 【III】Class III loads: 1. Loads that do not fall under Class I or Class II loads are considered Class III loads. ====Load power supply method: ==== 1. Primary load: Dual power supply, with both power sources {not} being damaged simultaneously. 2. Class I particularly important loads: dual power supply + emergency power supply (providing power separately for these loads). ) The power supply switching time for the AND device meets the device’s requirement regarding the allowable duration of power interruption. ====Instrument power supply load: ==== 1. In most cases, the power supply for instruments is considered a class-1 critically important load. A UPS needs to be installed. 2. In a few cases, the power supply for the instruments falls under category III load, and there is no need to install a UPS. Automatic control instruments