I have a question regarding intrinsically safe junction boxes and terminal blocks
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Regarding whether there are intrinsically safe, explosion-proof versions of junction boxes, I did some research online; some people say there aren’t any, while others claim that such versions do exist. The main reason given for the absence of such versions is that junction boxes don’t contain any electrical components that store energy, so even if a manufacturer claims that a junction box is intrinsically safe, it is actually of enhanced safety type. But if there are no intrinsically safe junction boxes, then can’t any junction boxes be used in Zone 0 installations? 2. Information on intrinsically safe junction boxes can also be found online; an important point is that the terminal blocks used are intrinsically safe ones, while the box itself has nothing special about it. I would like to ask whether there is such a concept as intrinsically safe for terminal blocks, and whether they can obtain intrinsically safe certification If only a junction box equipped with intrinsically safe terminals can be called an intrinsically safe junction box, then the terminals in increased safety and flameproof junction boxes are not intrinsically safe terminals, right? However, an increased safety junction box can be installed in Zone 1 to connect intrinsically safe instruments. To form an intrinsically safe circuit, it is necessary that every device in that circuit be intrinsically safe. If the terminals inside the increased safety junction box are also intrinsically safe, then what is the difference between it and an intrinsically safe junction box?
I’ve never heard of intrinsically safe junction boxes. The requirement for intrinsically safety is to install safety barriers at the control system side to limit power, and specialized intrinsically safe cables must be used. Field junction boxes can use increased safety types, as long as they meet the requirements for Zone 1. As for Zone 0 that you mentioned, Zone 0 conditions generally do not occur within such devices; usually, it’s possible to classify the area as Zone 1 when determining explosion-proof zones
I haven’t heard of any “intrinsic safety wiring boxes”; most of those I’ve seen are “explosion-proof wiring boxes” or “waterproof wiring boxes”.
Terminals are simple components; they don’t require any special certification, right? For intrinsically safe use, the color should be blue
First, it is necessary to determine the exact meaning of ‘intrinsic safety’. Intrinsic safety essentially means that in areas where explosive gases, vapors, or dusts are present and their concentrations reach the level at which explosion can occur, the sparks generated by the circuits and the components within those circuits do not possess enough energy to ignite such explosive mixtures. Similarly, the surface temperature of the circuits and their components is not high enough to ignite these explosive mixtures. To this end, it is necessary to limit the energy of the circuit and the components within it. The wiring box or wiring terminals themselves do not possess any energy; they are merely used for wiring, so there should be no concept of ‘intrinsically safe wiring box/intrinsically safe wiring terminals’. However, for the junction boxes/terminals used in intrinsically safe circuits, certain special considerations are required due to their unique properties; as a result, some suppliers refer to these junction boxes/terminals as intrinsically safe junction boxes/terminals, although strictly speaking this terminology is inaccurate.
View: There are no intrinsically safe junction boxes or intrinsically safe terminals in the world. Terminals are simple components that do not possess energy storage capabilities; therefore, they require no certification. As long as there is a safety barrier to limit energy, they can be used in intrinsically safe circuits. Terminals are the same as dry contact switches and thermocouples; they are inherently intrinsically safe devices, so the concept of intrinsically safe or non-intrinsically safe does not apply to them.
Intrinsic safety refers to the circuit, not any individual component within it