Knowledge about explosion-proof Lighting switches explained

What is an explosion proof lighting switch?

An explosion-proof switch is an electrical control device designed for flammable and explosive environments, with the core function of achieving safe and reliable electrical control in extremely hazardous locations. The device is designed to follow strict international standards (e.g. IEC 60079) to ensure that any form of ignition source is prevented from arising in potentially explosive gas or dust environments, thus avoiding the initiation of a fire or explosion.

The housings of explosion-proof switches are usually made of high-strength metal materials that are specially sealed to withstand harsh operating conditions. The internal circuit design utilizes isolation technology to completely isolate the electrical components from the external environment, ensuring that even in the event of an internal electrical failure, it will not cause the ignition of an external explosive mixture.

In terms of operating mechanism, the explosion-proof switch adopts mechanical or electronic means to realize rapid circuit disconnection or connection, and at the same time, it is equipped with safety functions such as overload protection and short-circuit protection. Their structural design takes into account the need for easy cleaning and maintenance, facilitating stable long-term operation in harsh environments.

In addition, the wiring of the explosion-proof switch has been carefully designed to accommodate different installation requirements and cable types, ensuring a solid connection and easy operation. During installation, strict explosion-proof specifications must be followed to ensure that all connections meet explosion-proof requirements.

There is a wide range of explosion-proof switch products on the market, including but not limited to explosion-proof, safety-increasing, intrinsically safe and other different levels of protection to meet the needs of different hazardous areas. When choosing an explosion-proof switch, users should determine the appropriate product model based on specific application scenarios (e.g., zoning of explosive gas environments, temperature groups, etc.) and electrical parameters (e.g., voltage and current levels).

Basic knowledge of explosion-proof switch

1. Explosion-proof switch is a kind of switch with anti-explosion function, which is mainly used to prevent the explosion accident caused by equipment failure, misoperation and other reasons.

2. The main features of explosion-proof switch are good sealing, corrosion resistance, impact resistance, dustproof and waterproof.

3. Explosion-proof switches are divided into two types: ordinary type and intelligent type. Intelligent explosion-proof switches have functions such as remote monitoring and automatic diagnosis.

Wiring steps of explosion-proof switch

1. Firstly, check whether the model and parameters of the explosion-proof switch meet the actual demand, and then choose the suitable explosion-proof switch for installation.

2、Prepare tools: screwdriver, wrench, cable stripping pliers, multimeter and so on.

3、Disconnect the power supply: Before any electrical operation, be sure to cut off the power supply to ensure personal safety.

4、Dismantle the original equipment: use screwdrivers, wrenches and other tools to remove the switch from the original equipment, taking care not to damage the surface of the equipment.

5、Installation of explosion-proof switch: Install the explosion-proof switch correctly on the equipment according to the requirements of the manual, and take care not to get the installation position wrong.

6、Connect the cable: Strip the cable with stripping pliers to remove the outer insulation layer of the cable, and then insert the cable into the terminals of the explosion-proof switch, taking care not to insert the opposite or insert tightly.

7、Fix the cable: use a screwdriver to fix the cable on the device, make sure the cable will not be loose.

8、Check the wiring: Use a multimeter to check whether the wiring of the explosion-proof switch is correct, and make sure that there is no short circuit, broken circuit and other problems.

9, power test: after confirming that the wiring is correct, connect the power supply to the equipment and observe whether the explosion-proof switch works normally.

10、Complete installation: If everything is normal, you can reset the equipment to complete the installation of the explosion-proof switch.

Precautions

1, in the installation of explosion-proof switch, be sure to follow the manufacturer’s instructions to ensure safety and reliability.

2、During the wiring process, pay attention to prevent the cable short circuit, disconnection and other problems, so as not to affect the normal operation of the equipment.

3、Before the energization test, make sure that the equipment has been completely disconnected to avoid electric shock accidents.

4、In daily use, the explosion-proof switch should be checked and maintained regularly to ensure its normal operation.

Wiring process of underground explosion-proof switch

1、No damage to the terminal insulating table, no damage to the terminal threads, no discharge traces, and the insulating table is intact without cracks.

2、Wiring without burrs, no protruding wires in the front connection part of the core wire.

3, wiring without crooked neck wiring, bend arc natural and smooth, avoid sharp bends, right-angle bends, phase line to avoid contact with the wall.

4, no pressure plate (washer) to press the insulation layer.

5, the wire is not exposed to excessive length, the core insulation and the core length between the compression part of the terminal is not greater than 5mm (1 ~ 3mm is appropriate).

6, sub-phase core wire insulation is not scarred, wiring without cross wiring, a phase of the insulation does not touch the other phase conductor, wiring neatly chopped head, wiring the remaining head is not over-length, the front of the core from the terminal part of the over-length length is not greater than 2mm.

7, terminal claws are not deformed, uniform distribution, terminal to flatten the spring pad, the core is not strung as qualified.

8, the length of the grounding core line is qualified, the grounding line along the cavity wall natural arrangement, not easy to too long or too short (to loosen the line mouth, pull the cable, the phase line pulled tight or loose, the ground line does not fall shall prevail)

9, explosion-proof surface coated with petroleum jelly, cable sheath cut neatly, the length of the sheath into the cavity wall 5 ~ 15mm, (if the cable thick penetration into the cable can be worn into the part of the file fine but the sheath and sealing ring combined with the part shall not be filed fine), the wiring cavity is clean and free of sundries placed in an appropriate amount of desiccant.

10, grounding bolt nut washer is not allowed to coat the insulator, good contact.

11, there must be a power warning sign and correctly installed.

12, the core wire crimping first pressure ground, and then pressure phase line.

13, control wiring in general: start line (red), self-protection line (white), power line (blue).

14, explosion-proof surface screws shall not be loose, to spring pads pressed flat as a benchmark, screws exposed 1 to 3 buckles, the same part of the bolt specifications are consistent.

15, threaded structure of the junction of the threads of the minimum number of teeth together with the number of buttons is not less than 6 buckles, cable connection sealing ring width is not less than or equal to 0.7 times the outer diameter of the cable, but must be greater than 10mm.

16, the sealing ring inner diameter and cable outer diameter difference of not more than 1mm, the sealing ring outer diameter and the inner diameter of the feeder device should be in accordance with the following provisions.

(1) sealing ring outer diameter is less than or equal to 20mm, the sealing ring outer diameter and the inner diameter of the feeder device difference does not exceed 1mm

(2) sealing ring outer diameter is greater than 20mm, less than 60mm, sealing ring outer diameter and feed device inner diameter difference of not more than 1.5mm; (3) sealing ring outer diameter is greater than 60mm, not more than 1.5mm.

(3) When the outer diameter of the sealing ring is greater than 60mm, the difference between the outer diameter of the sealing ring and the inner diameter of the wire feeder should not exceed 2.0mm.

Pressure plate type wire feeder nozzle pressure tightly after the hand does not shake as a standard.