Sorrow! Is it necessary to ground the instrument enclosure?
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The last edit to this post was made by louhoo on 2019-4-8 at 11:52. The requirements regarding the grounding of instruments in chemical plants come from two sources: the \"Code for Design of Instrument Grounding in Petrochemical Industries\" (SH/T 3081-2003), which states: \"2.1.2 Field instruments powered by voltages below 36V do not require protective grounding, except in cases where they may come into contact with equipment operating at voltages higher than 36V.\" ” \"Code for Grounding Design of Instrumentation Systems\" (HG/T 20513-2014): \"3.1.3 Field instruments, transmitters, local switches, etc., powered by voltages below 36V need not be provided with protective grounding unless there is a specific requirement.\" ” Originally, it would have been sufficient to follow these two specifications; since the voltage of most instruments is below 36V, grounding is not necessary. But! Here’s the key point: an experienced expert said that one should not focus solely on these industry-specific standards; instead, it’s necessary to consider the relevant requirements of national standards. The standard mentioned by the expert is the \"Design Code for Instrumentation and Control Systems in Oil and Gas Fields and Pipeline Projects\" (GB/T 50892-2013). Since most areas within tank farms and processing units are classified as explosive hazard areas, according to this standard, almost all instruments need to be equipped with protective grounding. Experts say that these are already the requirements for surface engineering in oil fields; let alone facilities such as chemical plants. It is recommended to implement protective grounding regardless of whether the voltage is below 36V or not. I think what the experts say makes a lot of sense, but the design institute claims that this standard is not applicable to the chemical industry and therefore should not be followed. I think a response like that from a design institute is perfunctory. What do you all think – is only voltage taken into consideration, or are both the explosive environment and voltage considered?
This post was last edited by 275340019 on 2019-8-6 at 19:54. To understand the regulations, one should first look at the scope of application, the general provisions, and the explanations of the relevant articles. Don’t force it. See https://mp.wei*n.qq.com/s/uXgbpZQ3aepH3lGYw2WUSw
The older an expert gets, the more foolish they tend to become; their knowledge becomes outdated, their perspectives become stale, and their skills decline steadily............ Is grounding the enclosure really a form of protective grounding? What does casing grounding protect? What is the causal relationship between casing grounding and the measuring elements as well as the amplification circuit? Have you never designed electronic instruments before? Do you understand the working circuits of such instruments? As for grounding the enclosure, one needs to be able to explain why it’s necessary; just making up reasons won’t do. Nonsense! The people of Henan will go to Shaolin Temple and beat him to death. :lol
Damn, Yanran looks just like an old bald monk from Shaolin – I’m impressed! Impressive!
Working in an oil field, the metal enclosures of various transmitters used for automatic control in oil and gas facilities here are indeed grounded; this wasn’t done before – it was only implemented the year before last. The people who checked it later were even funnier… The Clear water equipment also had its grounding done…
The last edit to this post was made by 1111111 on 2019-4-9 at 10:31. 1. Can that old bald guy from Shaolin argue back? List all the instruments you can think of in order, and consider how these instruments are connected to the process equipment. 2. Unless the process equipment is made of plastic, the instrument housings will be automatically grounded when connected to the equipment, right? 3. If you connect the instrument enclosure to ground again, then you’re just playing around! If you play tricks, ground current may wander around inside the instrument enclosure – it’s like that old bastard taking off his pants and hitting the expert in the backside, get it? :lol
All instruments at Sichuan Petrochemical are required to be grounded, and the site is completely covered in spider webs: lol
Oh, you’ve hit the nail on the head; truly a masterful insight
All the instruments on our side are grounded