A wire pull calculator is a handy tool for electrical contractors and installers to determine the amount of force required to pull wires through a conduit. The calculator uses various factors such as the coefficient of friction, conduit inner diameter, length of conduit run, material factor, and wire gauge to calculate the wire pull force in pounds.

Formula for Wire Pull Calculator:

The formula used by the wire pull calculator is as follows:

Wire Pull Force (lbs) = Coefficient of Friction x Conduit Inner Diameter^2 x Length of Conduit Run / (Material Factor x Wire Gauge)

Where:

• Coefficient of Friction: This is the measure of the force required to move an object over another surface. It is expressed as a decimal value and depends on the surface type. For example, a value of 0.3 is commonly used for PVC conduit, while a value of 0.2 is used for EMT conduit.
• Conduit Inner Diameter (in): This is the diameter of the conduit through which the wire is being pulled.
• Length of Conduit Run (ft): This is the length of the conduit run through which the wire is being pulled.
• Material Factor: This is a factor that accounts for the physical properties of the wire being pulled and the conduit. For copper wire, a value of 0.008 is used, while for aluminum wire, a value of 0.006 is used.
• Wire Gauge: This is the size of the wire being pulled.

Example:

Suppose we want to pull a 12-gauge copper wire through a 100-foot PVC conduit with an inner diameter of 1 inch. We can use the wire pull calculator to determine the wire pull force as follows:

Coefficient of Friction = 0.3 (for PVC conduit) Conduit Inner Diameter (in) = 1 Length of Conduit Run (ft) = 100 Material Factor = 0.008 (for copper wire) Wire Gauge = 12

Wire Pull Force (lbs) = 0.3 x 1^2 x 100 / (0.008 x 12) Wire Pull Force (lbs) = 312.5 lbs

Therefore, a wire pull force of 312.5 pounds is required to pull a 12-gauge copper wire through a 100-foot PVC conduit with an inner diameter of 1 inch.

FAQs:

Why is it important to use a wire pull calculator?

A wire pull calculator helps electrical contractors and installers to determine the amount of force required to pull wires through a conduit. This ensures that the wire is not damaged during the pulling process, and the installation is done correctly.

What is the coefficient of friction, and how does it affect the wire pull force?

The coefficient of friction is the measure of the force required to move an object over another surface. A higher coefficient of friction means more force is required to move the wire through the conduit, resulting in a higher wire pull force.

What is the material factor, and how does it affect the wire pull force?

The material factor accounts for the physical properties of the wire being pulled and the conduit. For example, copper wire has a higher material factor than aluminum wire due to its higher tensile strength. A higher material factor results in a lower wire pull force.