Cut, Bend, and install electrical

conduits

Stephen Jones

Electrical Technology

Objectives

• Identify the types, sizes, and application of PVC conduits• State the advantages and disadvantages of using PVC conduits.• Identify fittings and fixtures used in the installation of PVC conduits.

• Given practical exercise, select tools and materials that conform to requirements.

• Make right-angle (90 degrees) bend in PVC conduit.• Given materials, Connect fittings to PVC.

• State the tools requires when working with PVC conduits.• Bends must be 90 degrees and without kinks.• Conduit must be measured, cut, and bent accurately to minimize

waste

PVC - Polyvinyl chloride

• The third-most widely produced plastic.

• Used in construction because it is more effective than traditional materials such as copper, iron or wood in pipe and profile applications.

• It is also used in clothing and upholstery, electrical cable insulation, Pipes (electrical and water), inflatable products, and many applications in which it replaces rubber.

Types of PVC pipes

Metal conduits

Non-metal conduits

Flexible conduits

Metal conduits

• Electrical metallic tubing (EMT), sometimes called thin-wall, is commonly used instead of galvanized rigid conduit (GRC), as it is less costly and lighter than GRC.

• More common in commercial and industrial buildings than in residential applications. EMT is generally made of coated steel, though it may be aluminum.

Electrical metallic tubing

Non-metal conduits

• PVC conduit

• Rigid Nonmetallic Conduit (RNMC)

• Electrical Nonmetallic Tubing (ENT)

Non-metal Conduits

• PVC conduit is the lightest in weight compared to other conduit materials, and usually lower in cost than other forms of conduit. The plastic material resists moisture and many corrosive substances.

• PVC conduit may be heated and bent in the field. 

PVC conduit

Flexible conduits

• Flexible conduits are used to connect to motors or other devices where isolation from vibration is useful, or where an excess number of fittings would be needed to use rigid connections. Electrical codes may restrict the length of a run of some types of flexible conduit.

• Flexible Metallic Conduit (FMC) – used in dry places.

• Liquidtight Flexible Metal Conduit (LFMC) – water resistant.

• Liquidtight Flexible Nonmetallic Conduit (LFNC) - flame-resistant,

Flexible conduits

Sizes of PVC Conduits.

• PVC Electrical Conduit Pipes are available in sizes of 20mm, 25mm, 32mm, 40mm, 50mm, & 63mm.

• 3m Lengths

Advantages of using PVC Conduits.

• Light in weight

• Easy to saw cut and clean.

• Easy to bend.

• Minimal condensation due to low thermal conductivity in wall of conduit.

• Cheap

• Excellent electrical and fire resistant properties

Disadvantages of using PVC Conduits.

• If insufficient adhesive is used the joints may not be waterproof.

• PVC expands about 5 times as much as steel and this expansion must be allowed for.

• PVC does not offer the same level of mechanical protection as steel.

• A separate Circuit Protective Conductor must be run inside the conduit.

Fittings and fixtures used in the installation of PVC conduits.

Saddles

• The saddle, is the device used for fixing conduit, they provide a very secure method of fixing for conduits.

Saddles

Plain Saddle Space bar Saddle

Coupling

Tee

surface junction box

Tools used when working with PVC Conduits

• Measuring tape

• Junior saw

• Spring bender

Types of Bends

• Right angled Bend

• Offset and Double Offset Bend