DCS requires a minimum power supply duration for PUS
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A UPS is required for the upper DCS system; what capacity is needed? How long does it last
It depends on the power capacity of your system. Our system has around 1500 points of power demand; the UPS is used to power the cabinets, the main server, and the monitor. The UPS should have a capacity of 30 KVA, with battery capacity of 30 AH, ensuring a runtime of no less than 60 minutes.
Requirements are determined based on the specific needs after a power outage; there is no fixed standard.
When placing an order as the owner, the DCS manufacturer first provides the system’s power consumption figure (which is generally accurate, plus a margin determined by the manufacturer). If there are other electrical devices such as analysis booths, the suppliers provide the power consumption data for those devices. The total of these values can be aggregated by the instrumentation team and rounded to a whole number; an additional margin of around 50% is then added to determine the capacity of the UPS. As for the power supply duration of a UPS system, it is generally required to be at least half an hour; the longer this duration, the more reliable it is, but the higher the investment cost.
SHT 3082-2003 Code for Design of Power Supply for Petrochemical Instruments: The backup power supply duration is 15–30 minutes. 1. The instrument design takes into account the estimated power consumption of on-site instruments, systems, and complete equipment; the design requirements are established based on the peak values, with a margin included ； 2. For UPS, general electrical procurement allows for some margin in terms of design and purchasing. So the actual backup power supply time is much longer than 30 minutes.
SHT 3082-2003 Code for Design of Power Supply for Petrochemical Instruments: The backup power supply duration is 15–30 minutes. 1. The instrument design takes into account the estimated power consumption of on-site instruments, systems, and complete equipment; the design requirements are established based on the peak values, with a margin included ； 2. For UPS, general electrical procurement allows for some margin in terms of design and purchasing. So the actual backup power supply time is much longer than 30 minutes.
The capacity is twice the system’s required capacity, and the time is usually 30 minutes.
It can be designed for 30 minutes, but the greater the redundancy, the better; however, this requires significant investment – a diesel generator can be added as a backup