Regarding the explosion protection of Rosemount transmitters
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Regarding the explosion-proof issue of Rosemount transmitters, this problem has been bothering me for some time. I first encountered it last year when choosing a pressure transmitter; I didn’t understand it at the time and just moved on. Now I’m facing the same issue again, and I’d like to seek advice from those with more experience. As shown in the figure below, this illustrates the explosion protection concepts for transmitters: K5 corresponds to E5, which refers to flameproofing, while I5 denotes intrinsically safe operation. In other words, K5 is intrinsically safe even when it is flameproofed. But can flameproofing meet the ExdIICT5 requirements? I was completely confused after reading the instructions, and I couldn’t find any information online either, so I’m reaching out to ask for help from everyone.
“What does “XP Class I, Category 1” mean?
As I understand it, explosion protection means that the enclosure is resistant to explosions; in the event of sparks or explosions occurring inside, it can prevent those explosions from spreading； Intrinsic safety serves to limit the current in the circuit; in other words, it enables dual protection through explosion isolation and intrinsic safety
The description of explosion protection in the Rosemount transmitter manual means that the transmitter is certified to both E5 and I5 standards； For cases with both explosion-proof certifications, Rosemount’s custom code is K5. Manufacturers like Rosemount have their own internal quality control standards; in fact, their products are manufactured in accordance with the highest requirements set by standards such as IEC (comparable to GB), those of the European Union, the United States, and so on, followed by various certifications ； During this process, if a standard cannot cover the content of the enterprise standards, repeated certification will be required ； For example, the intrinsically safe certification under the national standard GB does not emphasize explosion-proof requirements for the enclosure and against dust; Rosemount, on the other hand, provides explosion-proof certification that includes protection against dust on top of the intrinsically safe certification for its instruments. Therefore, such instruments will have multiple certification results; when selecting one, it can be used as long as the required aspects are covered by the certification results. For example: if you need intrinsically safe functionality, then as long as the product is certified for intrinsically safety, it can be used; other parameters such as explosion protection or dust resistance don’t need to be considered. Of course, having an explosion-proof enclosure is highly beneficial for the instrument’s environmental adaptability. .
This post was last edited by Sai Xin on 2022-6-3 00:41. You must be referring to Romon’s 248/644/3144 models; it’s actually just one product that has obtained various explosion-proof certifications: from various ** organizations； Intrinsic safety/expllosion-proof. Apply different labels. The K5 mentioned by the poster refers to FM’s explosion protection standards in the United States, which are divided into Classes I, B, C, and D ； ExdIICT5 of IECEx, ATEX, and even China’s NEPSI is not part of the same system. Anyway, the product is the same in every case and meets the explosion-proof requirements; it’s just the certificates referenced by the codes that differ, and that’s often what matters. Strictly speaking, explosion-proof products used in China should comply with China’s NEPSI explosion-proof standard, and only codes such as E3 and I3 can be used. Reasons for choosing K5: 1. It was chosen at random. 2. K5 is a good option, as it meets both intrinsically safe and explosion-proof requirements, making it ideal for stockpiling. . It can be used everywhere anyway. This must be a trick deliberately used by Romon. I’ve checked, and only Romon offers the option to combine intrinsically safe and explosion-proof features; other manufacturers of temperature transmitter displays in the market, including Yokogawa, Honeywell, E+H, WIKA, etc., classify their products into two categories on the label – either intrinsically safe or explosion-proof – even though it’s the same product.
The poster is referring to a transmitter, probably a differential pressure transmitter. The E3 and I3 temperatures you mentioned have such codes, but differential pressure transmitters do not.
Flame isolation means that the enclosure is strong and airtight, preventing sparks from entering or escaping, thereby eliminating the risk of explosion； Intrinsic safety means that the entire circuit cannot generate explosive sparks. So, intrinsically safe and flameproof systems are not contradictory; they are just two different approaches to explosion protection. Therefore, by using a flameproof enclosure for an intrinsically safe device, it becomes both flameproof and intrinsically safe at the same time. This is exactly what the model code means – the K5 is Rossmont’s internal standard.
This post was last edited by lotos1987 on 2022-6-7 21:20. I spoke with Rosemount’s manufacturers, who confirmed that the issue with \"fire protection standards in China\" mentioned for E3 is a translation problem, and suggested that Chinese series standards be used for projects within China.