Line post insulator 57-2L / 57-3L, genuine TIS standard

The Line post insulator (Line Post Insulator) is a device that engineers and contractors trust for installing high-voltage power lines, because it delivers superior stability, excellently durable against both wind and wire tension. If you are looking for a main line-holding insulator that meets the TIS standard and is durable in all weather, TETA INTERTRADE is ready to offer quality products that match your project needs — especially the popular Line post insulator 57-2L and 57-3L, which give stable installation.

What is a Line post insulator (LINE POST Insulator)?

A Line post insulator is a type of main high-voltage line-holding insulator designed for vertical or horizontal installation on pole structures. It holds power lines and acts as an insulator with high strength, mostly made from porcelain or polymer. The Line post insulator is more stable than a Suspension insulator because it is fixed directly to the pole, making it excellently durable against vibration and horizontal wind.

What does a Line post insulator do?

The main function of a Line post insulator is to support and hold high-voltage power lines, especially in the 22-33 kV power distribution system. It has a long-rod shape with a solid neck to prevent current puncture-through, and its top is made from high-quality porcelain to carry the wire, acting as an efficient electrical insulator that helps prevent high-voltage current leakage. It is durable and complies with electrical safety standards. 

How many types of Line post insulator are there?

Line post insulators can be classified by installation type and the material used, as well as by voltage rating. The standard models popular in the Provincial Electricity Authority (PEA) distribution system are divided by voltage as follows:

1. Line post insulator Type 57-2 : A standard model designed to support use in the 22 kV high-voltage system
2. Line post insulator Type 57-3 : Used to support the 33 kV high-voltage system
3. Line post insulator Type 57-4 : Another model also used to support the 33 kV high-voltage system, but differing in some structural or mechanical properties

In addition, some models have extra variants, such as the Line post insulator 57-2L, which passed a high impact test of 24 kA, and may be classified by material such as porcelain or composite; but in Thailand porcelain per the PEA standard is the main focus.

What applications are the Line post insulator 57-2L / 57-3L suited for?

The Line post insulator numbers 57-2L / 57-3L are highly suitable for high-voltage distribution systems (22 kV and 33 kV) where wires sit on straight poles, because their structure has high strength to bear shear and side wind loads (Horizontal Load) better than a Suspension insulator. They also suit installation in areas needing high wire stability, or urban areas that require a compact, tidy structure.

Details of the Line post insulator

TETA INTERTRADE sells the Line post insulator 57-2L / 57-3L that specifically meets the TIS standard. If you would like details of this main line-holding insulator — including price, specifications, and applications — you canask our teamdirectly.

Sample product list

• Line post insulator 57-2L Brand FAC
• Line post insulator 57-2L Brand SPI
• Line post insulator 57-3L Brand SPI

For businesses that need to buy in large quantities, we offer wholesale Line post insulator 57-2L / 57-3L, so you can manage your project costs efficiently.

Key features of the quality Line post insulator

• High insulation: Made from high-quality material, giving excellent electrical-insulation properties
• Tension-durable: A strong structure durable against tension and side shear from wires and wind
• Weather-durable: Withstands high heat, temperature changes, and sunlight without deteriorating easily
• long service life : High mechanical strength gives a long service life and reduces maintenance frequency
• Safe and standard-compliant: Certified to the industrial standard (TIS), confirming safety and quality

How to use the Line post insulator

• Use as the main line-holding insulator on straight poles in distribution work
• Use to hold wires horizontally, or in areas needing high side-tension capacity
• Install by fixing the insulator base firmly directly to the pole or Cross Arm

Buying recommendations

Choose a size or model appropriate to the system voltage rating, and consider the installation environment. In high-pollution areas, choosing the Anti-Pollution type or a type with the specified leakage distance will further improve insulation performance. If unsure, consult the expert engineering team and consider the PEA/ANSI standards and Creepage Distance before deciding to buy the Line post insulator 57-2L or other models for large projects.

Order the Line post insulator 57-2L / 57-3L, genuine TIS standard, at TETA INTERTRADE

For high-voltage equipment like the Line post insulator, whether model 57-2L or 57-3L, stability, strength, and the TIS standard must be the first considerations. Buying from a direct importer and trusted distributor like TETA INTERTRADE is therefore the best answer for your high-voltage distribution installation work.

• A full range of electrical equipment, meeting the needs of every type of project
• A direct importer from manufacturers, at great value
• Products in stock, ready for immediate delivery
• Advice from a team of engineers and technicians
• Free nationwide delivery

For those interested in buying a main line-holding insulator at wholesale prices, TETA INTERTRADE offers every model, with a team ready to advise for free, plus special discount promotions and free nationwide delivery. To order or ask for more information, contact us at

• LINE : https://lin.ee/NaG9WJP 
• Phone: 02-068-9690 or 086-308-3741