Explosion-proof positive pressure cabinet - wiring problem

In order to prevent the wiring from being connected by mistake, the relay terminal board of the explosion-proof circuit has to be easily recognizable. Relay terminal board should use flameproof circuit and non-explosion-proof circuit terminal board respectively independent structure, may choose to set the partition in the center to prevent mutual contact structure, together with clear and easy to set up the logo. When using a safety barrier as a relay terminal board, it is necessary to carefully study the orientation of the non-intrinsically safe circuit terminals of the flameproof circuit breaker terminals of the safety barrier and other safety barriers, and it must be properly equipped to prevent mutual contact. Under normal circumstances, the safety barrier of stainless steel explosion-proof positive pressure cabinet can sit on the relay terminal board. However, from the original purpose of the barrier, the flameproof circuit can be connected to the same barrier. Therefore, when using multiple barriers, it is necessary to prevent the two from being mixed.

In principle, it is necessary to install a relay terminal board that connects the flameproof circuit wiring and the distribution board wiring of the explosion-proof circuit inside the explosion-proof positive pressure cabinet. When the terminal board is connected with the wiring of the explosion-proof circuit, in order to prevent the explosion-proof circuit from being mixed with the non-flameproof circuit, the terminal row should use a protective structure that is exposed and charged with some cover.

It is necessary to install partitions or use shielded cables as required in the distribution board. However, it is not limited to the possibility of mixed contact or induction of non-explosive circuit wiring. When a non-explosive circuit with a safety adherence rating that exceeds the flameproof related equipment is located in the same switchboard. It is necessary to prevent the non-flameproof circuits connected to the explosion-proof devices from being subjected to mixed-touch and induction of non-bulk-proof circuits of superior value. When the voltage of the barrier test drive exceeds the safe adherence to the rated value, the function of the safety barrier may be damaged, and the rules have been made. When flameproof circuit wiring is laid through conduits or pipes, it is necessary to seal them in accordance with the regulations in order to prevent explosive mixtures from flowing through conduits or pipes to other hazardous or non-hazardous locations.

It is necessary to meet the requirements of the flameproof grounding line. In order to maintain the safety and explosion-proof function of the explosion-proof and explosion-proof positive pressure cabinet, when some circuits of the explosion-proof related equipment are grounded, it is necessary to use a copper wire with a cross-sectional area of ​​2 mm 2 or more as the grounding wire. A useful method should be used to prevent the occurrence of defects. , The active grounding current causes the ground potential to rise, damaging the flameproof explosion-proof function of the explosion-proof circuit. Other grounding electrodes must not be shared with the ground electrodes of other applications. It is best to set them separately. In addition, assuming that the grounding electrode is used in conjunction with a ground electrode such as a lightning arrester for other purposes, the earth potential of other systems may rise to earth potential and damage the flameproof explosion-proof function. Therefore, the grounding electrode must be set independently. However, it can also be shared with a ground electrode that requires only a small current to pass through.