Lesson Plan
Bending Basics: Conduit Calculations
Students will be able to identify different types of conduit bends and accurately calculate the measurements required for common electrical EMT conduit bends, including offsets, kicks, and saddles.
Accurate conduit bending is a fundamental skill for electricians. This lesson provides the mathematical foundation necessary to perform these tasks correctly, ensuring safe and compliant electrical installations in real-world scenarios.
Audience
10th Grade Students
Time
30 minutes
Approach
Direct instruction, guided practice, and a quick check for understanding.
Materials
Projector or Smartboard, Slide Deck: Conduit Math Essentials, Worksheet: Bend Like a Pro, and Pens/Pencils
Prep
Preparation
10 minutes
- Review the Slide Deck: Conduit Math Essentials and familiarize yourself with the content.
- Print enough copies of the Worksheet: Bend Like a Pro for each student.
- Ensure projector/smartboard is functional.
Step 1
Introduction & Hook
5 minutes
- Begin with a brief discussion: "Imagine you're an electrician installing wiring in a new building. The walls aren't perfectly straight, and pipes block your path. How do you get your wires from Point A to Point B without damaging them?"
- Introduce EMT conduit and the importance of precise bending. Show a picture or a short video clip (if available) of conduit being bent.
- Introduce the learning objective for the day.
Step 2
Direct Instruction: Conduit Math Essentials
15 minutes
- Use the Slide Deck: Conduit Math Essentials to guide the lesson.
- Slide 1: Title Slide
- Slide 2: Why Math Matters in Conduit Bending - Discuss real-world applications.
- Slide 3: Key Terms - Define 'offset', 'kick', 'saddle', 'take-up', 'shrinkage'.
- Slide 4: Offset Bends - Explain what an offset bend is and when it's used. Introduce the basic formula: (Desired Offset / Multiplier) = Distance Between Bends.
- Slide 5: Common Multipliers - Provide a table of common angles and their multipliers (e.g., 30-degree = 2, 45-degree = 1.414).
- Slide 6: Offset Example - Walk through a simple offset calculation together.
- Slide 7: Kick Bends - Explain what a kick bend is and its purpose. Introduce the concept of deducting for the bend.
- Slide 8: Kick Example - Work through a simple kick calculation.
- Slide 9: Saddle Bends (Overview) - Briefly introduce 3-point and 4-point saddles and their purpose (going over obstacles). Explain that these are more complex and often use specific marks on the bender, but the principle involves multiple offset bends.
- Slide 10: Quick Check! - Pose a quick question for students to answer individually or discuss with a neighbor.
Step 3
Guided Practice: Worksheet Time
8 minutes
- Distribute the Worksheet: Bend Like a Pro.
- Instruct students to work on the first few problems, focusing on offset and kick calculations.
- Circulate around the room, providing individual support and answering questions.
- Briefly review answers to the first few problems as a class.
Step 4
Wrap-up & Exit Ticket
2 minutes
- Ask students to share one new thing they learned or one question they still have.
- Collect the Worksheet: Bend Like a Pro for informal assessment.
Slide Deck
Bending Basics: Conduit Calculations
Understanding the Math Behind Electrical Conduit Bends!
Welcome students and introduce the topic of electrical conduit bending. Ask them to think about why precise measurements are important in construction.
Why Math Matters in Conduit Bending
• Electrical conduit protects wires.
• Buildings have obstacles (other pipes, beams).
• Conduit needs to be bent precisely to navigate these obstacles.
• Incorrect bends lead to wasted material, time, and potential safety hazards.
Explain that electricians use conduit to protect electrical wires. Ask students to consider what might happen if the bends aren't accurate.
Key Terms
• Conduit: A tube used to protect and route electrical wiring.
• Bender: The tool used to bend conduit.
• Offset: A bend with two equal angles that brings the conduit back into line to go around an obstacle.
• Kick: A single bend used to change the direction of the conduit or shift it slightly.
• Saddle: A series of bends (usually three or four) used to go over a larger obstruction, like a pipe.
Define each term clearly. Emphasize that these are the building blocks of conduit bending.
Offset Bends: Going Around Obstacles
• An offset bend helps conduit go around a shallow obstacle and then return to its original plane.
• It uses two equal bends in opposite directions.
• The key is to calculate the distance between these two bends.
Explain that offsets are common for going over small obstacles like a stud or a piece of strut.
Common Angle Multipliers for Offsets
• 30-degree bend: Multiplier = 2
• 45-degree bend: Multiplier = 1.414
• 22.5-degree bend: Multiplier = 2.6
Go over the common multipliers. Students will need to memorize or reference these.
Offset Example: Let's Calculate!
Problem: You need to make a 3-inch offset using two 30-degree bends. What is the distance between your two bends?
Formula: Distance Between Bends = Desired Offset x Multiplier
Solution:
Desired Offset = 3 inches
Multiplier for 30-degrees = 2
Distance = 3 inches * 2 = 6 inches
So, the two 30-degree bends should be 6 inches apart!
Walk through this example step-by-step. Encourage students to follow along and try it.
Kick Bends: Shifting Direction
• A kick bend is a single bend that changes the direction of the conduit or moves it away from a surface.
• It's simpler than an offset, but still requires precise measurement.
• You often need to account for 'shrinkage' (the conduit gets shorter after bending) for certain angles.
Explain that kicks are often used to shift the conduit slightly or create a single change in direction.
Kick Example: Keeping it Simple
Problem: You need to make a small kick to bring your conduit away from a wall by 1 inch using a 10-degree bend. How would you plan this?
For small kicks, the focus is on the angle and how much it moves the conduit. Electricians often have marks on their benders for common kick angles. The amount of shrinkage for small kicks is negligible for this introduction.
Key Idea: The angle determines how much the conduit shifts.
Walk through this example. Emphasize that for a kick, you often deduct for the bend's 'take-up'. For this introductory lesson, focus on the visual and purpose, keeping calculation simple.
Saddle Bends: Going Over Obstacles
• Saddle bends are used when you need to go over a larger object, like another pipe or structural beam.
• They consist of a center bend and two smaller 'wing' bends on either side.
• Often, the center bend is 45 degrees, and the two outside bends are 22.5 degrees.
Briefly describe saddles and their purpose. Mention that advanced calculations are involved, but the concept is crucial.
Quick Check!
If you need to make a 2-inch offset using two 45-degree bends, how far apart would you make your two bend marks? (Hint: Multiplier for 45-degrees is 1.414)
This is a quick informal check to see if students grasped the main concept of offsets. Encourage discussion.
Worksheet
Bend Like a Pro: Conduit Calculation Worksheet
Name: _________________________ Date: _________________________
Part 1: Offset Bends
An offset bend helps your conduit go around an obstacle and return to its original path. Remember the formula: Distance Between Bends = Desired Offset x Multiplier.
-
You need to create a 4-inch offset using two 30-degree bends. How far apart should your two bend marks be?
- Multiplier for 30-degrees = 2
- Show your work:
- Distance between bends: ____________________
-
An electrical box is 2.5 inches away from a wall. You need to bend your conduit to connect to it using two 45-degree bends. How far apart should your bend marks be?
- Multiplier for 45-degrees = 1.414
- Show your work:
- Distance between bends: ____________________
-
Challenge Question: You have a 6-inch offset to make. You decide to use two 22.5-degree bends. What is the distance between your bends?
- Multiplier for 22.5-degrees = 2.6
- Show your work:
- Distance between bends: ____________________
Part 2: Kick Bends
A kick bend is a single bend that changes the direction of your conduit or moves it slightly from a surface.
-
Why would an electrician use a kick bend instead of an offset?
-
Describe a real-world scenario where a kick bend would be useful.
-
If you make a 10-degree kick in a piece of conduit, how does it affect the overall path of the conduit?
Part 3: Saddle Bends
Saddle bends are used to go over larger objects like pipes or beams.
-
What is the main purpose of a saddle bend?
-
Briefly describe the difference between an offset and a saddle bend.
Answer Key
Bend Like a Pro: Conduit Calculation Worksheet - Answer Key
Part 1: Offset Bends
-
You need to create a 4-inch offset using two 30-degree bends. How far apart should your two bend marks be?
- Multiplier for 30-degrees = 2
- Show your work:
Desired Offset = 4 inches
Multiplier = 2
Distance = 4 inches * 2 = 8 inches - Distance between bends: 8 inches
-
An electrical box is 2.5 inches away from a wall. You need to bend your conduit to connect to it using two 45-degree bends. How far apart should your bend marks be?
- Multiplier for 45-degrees = 1.414
- Show your work:
Desired Offset = 2.5 inches
Multiplier = 1.414
Distance = 2.5 inches * 1.414 = 3.535 inches (round to 3.5 inches) - Distance between bends: 3.5 inches
-
Challenge Question: You have a 6-inch offset to make. You decide to use two 22.5-degree bends. What is the distance between your bends?
- Multiplier for 22.5-degrees = 2.6
- Show your work:
Desired Offset = 6 inches
Multiplier = 2.6
Distance = 6 inches * 2.6 = 15.6 inches - Distance between bends: 15.6 inches
Part 2: Kick Bends
-
Why would an electrician use a kick bend instead of an offset?
A kick bend is used for a single, smaller change in direction or to move the conduit away from a surface. An offset is used to go around a distinct obstacle and bring the conduit back into the original alignment. -
Describe a real-world scenario where a kick bend would be useful.
- To slightly shift conduit away from a wall to align with a box.
- To make a small angle to avoid a protruding screw or minor imperfection on a surface.
- To align conduit coming out of the ground into a panel.
-
If you make a 10-degree kick in a piece of conduit, how does it affect the overall path of the conduit?
It will change the angle of the conduit by 10 degrees, causing it to deviate from its original straight path. The end of the conduit will be offset from where it would have been if it remained straight.
Part 3: Saddle Bends
-
What is the main purpose of a saddle bend?
The main purpose of a saddle bend is to allow the conduit to pass over a larger obstruction, such as another pipe or a beam, while maintaining a smooth and continuous path. -
Briefly describe the difference between an offset and a saddle bend.
An offset uses two bends to go around a shallow obstruction and return to the original plane. A saddle bend uses three or four bends (a center bend and two or three wing bends) to go over a larger, more significant obstruction.