What standards does Thailand have for the installation of strong and weak electricity distribution cabinets?

Thailand's installation standards for high and weak current distribution cabinets are mainly based on TISI and related international standards. The following are some common requirements:

Installation environment and foundation

Environmental requirements: the distribution cabinet should be installed in a dry, well-ventilated place without corrosive gas, and the ambient temperature and humidity should meet the requirements of the equipment, so as to avoid being installed in a place susceptible to water immersion, vibration or strong electromagnetic interference. For outdoor installation of power distribution cabinets, good waterproof, sunscreen and dustproof measures are required.

Foundation requirements: the installation of foundation steel should be firm, and the deviation of levelness and verticality should be controlled within a certain range. The top of foundation steel should be a certain distance above the ground, usually about 10mm, so as to facilitate anti-corrosion treatment and cable entry and exit. The foundation steel shall be reliably grounded, with at least two grounding connection points, and the grounding resistance shall meet the design requirements.

equipment installation

Cabinet installation: the power distribution cabinet should be installed according to the design requirements, with accurate installation position and firm fixation. The allowable deviation of the verticality of the cabinet should not be greater than 1.5‰, the joint between them should not be greater than 2mm, and the deviation of the column disk surface should not be greater than 5 mm. For the wall-mounted distribution box, expansion bolts can be used to fix it on the wall, but dovetail bolts should be embedded in the hollow brick or block wall or pull bolts should be used to fix it.

Installation of internal components: The electrical components in the power distribution cabinet should be installed firmly and arranged neatly for easy operation and maintenance. The spacing between elements should meet the electrical safety requirements, and the heating elements should be installed at the top of the cabinet or in a position where heat dissipation is easy. The installation direction of components should be correct, the wiring should be firm and reliable, and the contact should be good, and there should be no looseness, virtual connection and other phenomena.

Line connection

High-voltage lines: The specifications and models of high-voltage incoming and outgoing lines shall meet the design requirements, and cables or wires shall be laid in an orderly manner to avoid crossing and squeezing. The bending radius of the cable shall conform to the regulations, and the production of the terminal head and intermediate joint of the cable shall be standardized with good insulation performance. Busbars in the power distribution cabinet should be arranged neatly, with clear phase sequence identification. The connection of busbars should use special connection hardware, and the connection is firm, and the contact resistance meets the requirements.

Weak current lines: weak current lines, such as communication lines and network lines, should be kept at a certain distance from strong current lines, and the spacing is generally required to be above 300mm to prevent strong current from interfering with weak current signals. The laying of weak current lines should avoid mechanical damage and electromagnetic interference, and the connection of lines should adopt special connectors with reliable connection and good signal transmission quality.

Grounding and safety

Grounding system: the metal shell, frame and foundation steel of the distribution cabinet should be reliably grounded, and the grounding resistance should meet the design requirements, and generally should not be greater than the specified value. It is forbidden to set switches or fuses on the grounding wire, and it should be convenient for inspection and maintenance. For TN system, neutral line (N line) and protection line (PE line) should be strictly separated and not mixed; For TT system and IT system, the independence and reliability of grounding system should be ensured.

Safety protection: the power distribution cabinet should be equipped with door locks or other protective devices to prevent non-professionals from opening the cabinet door at will. The electrical components in the cabinet should have obvious signs and operating instructions, which is convenient for operators to operate and maintain. Safety warning signs should be set around the distribution cabinet, such as "high voltage danger" and "no closing" to remind personnel to pay attention to safety.

Other requirements

Identification and nameplate: The information such as equipment name, serial number, use and voltage grade shall be marked on the power distribution cabinet, and the identification shall be clear, accurate and durable. Each loop in the cabinet should also be marked with information such as loop name, number and load nature, so as to facilitate operation and maintenance.

Ventilation and heat dissipation: In order to ensure the normal operation of electrical components in the power distribution cabinet, the power distribution cabinet should have good ventilation conditions, and natural ventilation or forced ventilation can be adopted. For components with heat dissipation requirements, the heat dissipation space should be ensured to be unobstructed, and cooling fans or other cooling devices can be installed if necessary.

In addition, when installing the power distribution project in Thailand, it is necessary to comply with the local electrical safety regulations and related regulations, and may need to be accepted and approved by the local power department or relevant institutions. If it involves the installation of power distribution cabinets in special industries or places, it should also meet the corresponding industry standards and norms.