Wiring Systems & Enclosures

State the constructional features, applications, advantages, and limitations of common types of cable and conductor containment systems.

• Cable trays, used for supporting insulated electric cables, are advantageous for their ease of installation but limited by their exposure to environmental factors.

• Cable ladders, used for heavy-duty cable support, are advantageous for their strength but limited by their weight.

• Conduit systems, used for protecting electrical wiring, are advantageous for their protection but limited by their inflexibility.

• All of the above

Environmental factors can affect the selection of wiring systems, associated equipment, and enclosures by:

• Increasing the risk of corrosion and requiring corrosion-resistant materials.

• Reducing the need for insulation and allowing for simpler designs.

• Eliminating the need for grounding and enhancing safety.

• Decreasing the importance of temperature control and allowing for more flexibility.

State the types of wiring systems and associated equipment used for lighting systems, power systems (final circuits), and power systems (radial circuits).

• Lighting systems, power systems (final circuits), and power systems (radial circuits) use conduit wiring, surface wiring, and concealed wiring.

• Lighting systems use conduit wiring; power systems (final circuits) use surface wiring; power systems (radial circuits) use concealed wiring.

• Lighting systems use concealed wiring; power systems (final circuits) use conduit wiring; power systems (radial circuits) use surface wiring.

• Lighting systems, power systems (final circuits), and power systems (radial circuits) use surface wiring, conduit wiring, and concealed wiring.

What is the main use of cable trays?

• Residential wiring

• Industrial and commercial premises

• Decorative purposes

• None of the above

What is the main advantage of using cable trays?

• They are decorative

• They support cables along the whole of their run

• They are expensive

• They are heavy

Light gauge is often called ______ and is easier to bend than heavy gauge.

• single flange

• double flange

• triple flange

• quad flange

What is the function of a tray bending machine?

• It is used for cutting steel trays.

• It provides the same functions as a conduit bender but applied to steel tray work.

• It is used for welding steel trays.

• It is used for painting steel trays.

What is used to fix cables to the tray to prevent them from falling in the event of a fire?

• Plastic ties

• Steel/metal cable ties

• Rubber bands

• String

What additional benefit does a perforated tray provide?

• Increases weight

• Helps cables dissipate heat

• Reduces cost

• Improves appearance

Fill in the blank: 90º bends should be done without _______ the tray.

• breaking

• bending

• twisting

• cutting