EIM 1 PART 2

• City of Good Character
• DISCIPLINE • GOOD TASTE • EXCELLENCE
• Jeramil G. Moreno (SST I, PHS)
• Rogerson J. Pulido (SST II, MNHS)
• Christopher E. Mercado
• TLE-Industrial Arts
• Electrical Installation and Maintenance
• First Quarter-Module 1 Part 2
• Rigid Nonmetallic Conduit
• Department of Education
• National Capital Region
• SCHOOLS DIVISION OFFICE
• MARIKINA CITY
• Rigid Nonmetallic Conduit (RNC)


  One of the wiring methods approved by the Philippine Electrical Code
• Preparing and properly bending RNC

  1. Cutting

  2. Heating

  3. Bending
• Heat sources for bending RNC

  • Heat box (most convenient)
  • Heat gun (usual tool)
  • Blow torch
  • Stove
• Field bends


  Bends made on site to suit the need for installing the system
• Common bend defects

  • Burn
  • Kinks or groove
  • Reduced diameter
• Vinyl chloride


  Used to make polyvinyl chloride (PVC) plastic and vinyl products
• Acute (short-term) exposure to high levels of vinyl chloride in air


  Central nervous system effects (dizziness, drowsiness, headaches)
• Chronic (long-term) exposure to vinyl chloride

  Liver damage, increased risk of liver cancer
• The U.S. Environmental Protection Agency (EPA) has classified vinyl chloride as a Group A, human carcinogen
• Minimum radius of bend

  For a 20mm diameter conduit, the minimum radius is 115mm
• Types of RNC bends

  • Elbow
  • Offset bend
  • Saddle bend
• Procedure in Preparing a 90° Bend


  1. Wear appropriate PPE

  2. Prepare tools, equipment and materials

  3. Draw a guide on the floor

  4. Mark the center of the bend

  5. Apply heat to soften the marked part

  6. Lay the conduit on the floor and bend to 90°

  7. Wipe with damp cloth to facilitate cooling

  8. Check the finished work and do housekeeping
• Procedure in Preparing an Off-set Bend

  1. Wear appropriate PPE

  2. Prepare tools and materials

  3. Measure the height of the box's knockout

  4. Draw a guide on the floor

  5. Mark the conduit

  6. Apply heat and bend following the guide

  7. Wipe with damp cloth

  8. Check the finished work and do housekeeping
• Extra precaution should be applied when using a heat gun
• Safety is the priority when bending RNC
• Wear a mask when applying heat to the RNC to avoid inhaling the fumes
• The fumes generated by the heated conduit are dangerous to health
• Procedure in Preparing an Off-set Bend intended for a panel box

  1. Wear appropriate PPE

  2. Prepare all the necessary tools and materials

  3. Measure the height of the box's knockout

  4. Draw the height of elevation on the floor

  5. Measure and mark at least 5 inches from the end of the conduit

  6. From the first mark, measure, and mark 6 inches

  7. If the conduit is already softened evenly, turn off the heat gun and lay down the pipe on the guide drawn on the floor. Pull both ends on the opposite side while following your guide

  8. If the desired shape is formed, put one of your feet on one side and wipe the conduit with a damp cloth applying pressure on top of it if ever it flattens

  9. Check the finished work. The offset must be like the picture on the right. Do the necessary housekeeping
• The steps in preparing an off-set bend intended for panel box are the following
• Safety is our priority. Do not forget to cover your nose and mouth with mask when applying heat to the RNC. The fume generated by the heated conduit, if inhaled, is dangerous to health.
• Remember this...
• The following steps should be followed to make a 90° Bend without bend defects.
• Procedure in Preparing a 90° Bend


  1. Wear appropriate PPE

  2. Prepare all the necessary tools, equipment, and materials for the job

  3. Draw a right angle on the floor using a try square or L-square

  4. Determine and mark the center of the bend at approximately 6 inches from the center mark to both ends of it

  5. Apply heat to soften the marked part. Rotate the conduit while swaying the heat gun to apply heat evenly

  6. When the marked portion is already softened evenly, lay the conduit on the floor with one foot stepping on one end of it

  7. Using one hand, hold the other end of the conduit and make a 90° bend. Use the other hand to wipe the conduit

  8. Wipe the conduit entirely with a damp cloth to facilitate faster cooling

  9. Check the finished work and do the necessary housekeeping