What should be considered when installing safety barriers?

OP, the more similar posts there are, the better – it allows everyone to share together. What often seems like a simple question is always ambiguous.

Choosing the right model is the most fundamental thing; secondly, it is necessary to install and use it strictly in accordance with the instructions.

Do not forget to configure temperature-related safety discrimination

(My previous posts, put together for easier sharing by everyone) Intrinsic safety explosion protection is a concept of system-level explosion prevention, consisting of the following three components: devices associated with the safe area – safety barriers； Intrinsic safety field devices for hazardous locations – Intrinsic safety instruments ； Connection cables between hazardous and safe areas – intrinsically safe cables. Currently, intrinsically safe systems are certified using either “system certification” or “circuit certification”. In addition to certifying intrinsically safe instruments, safety barriers, and intrinsically safe cables separately, this approach also involves certifying intrinsically safe devices and associated devices as specific combinations. Once such a combination is certified, the intrinsically safe devices and associated devices cannot be replaced with devices of other models or specifications that have not been certified by a testing institution according to this combination. In general, intrinsically safe instruments are divided into two main categories: simple instruments and complex instruments. Simple instruments do not require intrinsically safety certification; they can be used in conjunction with intrinsically safe barriers that already have such certification to form an intrinsically safe explosion-proof system. If it is not a simple instrument, it must obtain intrinsically safe certification and, together with a safety barrier that also has intrinsically safe certification, form an intrinsically safe system. Safety barrier certification: The certification of safety barriers or intrinsically safe instruments consists of two parts – an explosion-proof mark and specific safety parameters. The main safety parameter of intrinsically safe instruments, Ui, represents the maximum fault voltage that can be applied ； Ii: the maximum fault current allowed for input ； Maximum power allowed to be inputted by Pi ； Equivalent capacitance of the Ci instrument ； The equivalent inductance of the Li instrument. The main safety parameter of the safety barrier, Uo, is the maximum voltage that can be output, that is, the safety voltage limit ； The maximum current that Io can output, i.e., the safe current limit ； Maximum power that Po can output ； Maximum loop capacitance allowed by Co ； The maximum loop inductance allowed by Lo. Intrinsic safety system certification procedures and principles Safety barrier certification ； Intrinsic safety instrument certification ； Cable certification ； The safety parameters of safety barriers, intrinsically safe instruments, and cables must meet i) voltage and current inequalities ； ⅱ) Inductance and capacitance inequalities. As can be seen from the above introduction to explosion-proof parameter certification, to constitute a intrinsically safe explosion-proof system, (1) the use of energy storage components in existing equipment should be minimized as much as possible ； ⑵Choose connection cables with as low distributed capacitance and distributed inductance as possible ； ⑶The safety barrier should be able to maintain safety reliably even in the event of a failure.

The following points should be considered when installing the safety barrier: 1. The installation of the safety barrier must be carried out strictly in accordance with the construction drawings, and the location codes specified in the drawings must be used； 2. During installation, operating under power is strictly prohibited ； 3. After installation, power testing can be carried out only after passing the inspection ； 4. Wires leading to hazardous areas should be blue intrinsically safe wires; the cross-sectional area of the soft copper in such wires must be greater than 0.5 mm2, and their insulation strength must be above 500 V. 5. The wiring wires for the intrinsically safe side (the blue side) of the safety barrier and those for the non-intrinsically safe circuit sides should be laid separately in the cable trays, with each type of wire having its own protective sleeve. No other power cables are allowed inside the wiring gland on the intrinsically safe side, including those used by other intrinsically safe circuits. 6. For Zener-type safety barriers, the requirement that the busbars be connected to the intrinsically safe circuit must also be considered; the connection resistance should be less than 1R ；