With ongoing upgrades in Thailand’s power grid, triple-bundled conductors are being used more frequently on high-voltage transmission lines. However, many contractors have found that if the pulley groove is not properly matched to the conductor, or if rotation is not sufficiently smooth, the subconductors are prone to surface scratches, minor twisting and local dents during stringing. These issues not only affect appearance but may also impact long-term reliability.

In this project, after comparing several options, the Thai contractor chose the SHSQN320X60(S) Triple Stringing Pulleyas their dedicated solution for triple-bundled conductors. This model uses 320×60 mm nylon sheaves with carefully profiled grooves that match the conductor size. The design provides adequate strength while being gentle on the conductor surface. With the triple-sheave configuration, each subconductor is guided separately, which reduces mutual compression and mechanical damage.

During stringing, site engineers noticed a clear improvement in conductor behaviour as it passed through the pulleys:

• After stringing, surface scratches and dents on the conductors were significantly reduced.

• The bundled conductors maintained a more stable position, with less twisting and crossing between subconductors.

• Subsequent sagging and hardware installation work went more smoothly, with almost no rework caused by conductor appearance issues.

In their acceptance report, the customer noted that the SHSQN320X60(S) Triple Stringing Pulley exceeded expectations in terms of conductor protection. It not only improved final conductor quality but also helped reduce potential complaints and future maintenance costs related to surface defects. As a result, the contractor plans to adopt this model as a preferred pulley solution for upcoming triple-bundled conductor projects in Thailand.