What is the minimum groove size of the bull-wheel as a percentage of the conductor diameter?

The correct answer is based on industry standards for the size of the grooves in the bull-wheel used for handling conductors. The minimum groove size being 125% of the conductor diameter ensures that there is adequate clearance and support for the conductor as it is pulled through the bull-wheel.

Using 125% allows for a better grip on the conductor and reduces the risk of damage, such as flattening or crushing the conductor. This percentage also accounts for the natural flexibility of conductors, providing enough space for thermal expansion and any slight movements while the conductor is under tension.

In contrast, other percentages, such as 100%, 150%, or 175%, either do not provide sufficient space for safe operation or may result in excess slack that could lead to improper handling of the conductor. Thus, maintaining a groove size at 125% of the conductor diameter ensures both safety and reliability in electric transmission line work.