The PT100 is intrinsically safe for use in explosion-proof areas, while the junction box is waterproof – don’t understand?
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This post was last edited by zhangjin200274 on 2018-3-21 at 23:17. I would like to ask everyone: for PT100 sensors used in explosion-proof areas, the explosion-proof classification is E*aⅡCT4. Should a waterproof type of junction box be used, rather than an explosion-proof one? Not sure about something?
Are there intrinsically safe thermoresistors? It seems that all the junction boxes are of the waterproof or explosion-proof type.
The explosion-proof structure and the protective structure of wiring are different concepts. Intrinsic safety does not necessarily imply a high level of protection; many intrinsically safe instruments or devices, when installed indoors or in cabinets, have a very low level of protection, and may not even be able to resist rainwater.
This post was last edited by zhangjin200274 on 2018-3-21 23:13. Perhaps I expressed myself incorrectly; the explosion protection category is E*aⅡCT4. Then why is a waterproof junction box used instead of an explosion-proof one? Not sure about something?
The explosion protection category is E*aⅡCT4; why is a waterproof junction box used instead of an explosion-proof one? Not sure about something?
You should first learn about explosion-proof and protective zones. These are two different types of requirements.
Intrinsic safety devices no longer require an explosion-proof enclosure; otherwise, it would be sufficient to use a regular circuit along with an explosion-proof enclosure. In that case, intrinsically safe is not necessary
These are two requirements that need to be met simultaneously
Your explosion-proof requirement is an explosion-proof environment requirement, right? If the instrument is already intrinsically safe and connected to an intrinsically safe circuit, it means that this instrument cannot cause an explosion; then why is it still necessary to have an explosion-proof enclosure? Explosion isolation generally refers to the ability to confine potential explosions within an explosion-proof enclosure; conversely, it is not necessary for the area inside the explosion-proof enclosure to be intrinsically safe.