1. Elementary Knowledge of the Connection of Lines for Mobile Devices and Appliances and their Use

Mobile service equipment such as devices and appliances are used in all fields of economy, production and everyday life.

They are connected to the electric mains be reusable cables, which are not fixed such as extension cords, mobile multi-way connectors, flexible cables and so on.

Survey of cables

Insulated cables

- Conductors are fitted with a plastic or rubber insulation (core insulation).
- Several conductors are twisted and covered by a common sheath (sheath insulation).

Bare cables

- Uninsulated conductors

Cables for mobile installation

- Flexible (mobile) insulated cables.

Lines for permanent installation

- Lines are fixed - permanent installation.

Characteristics of lines for mobile installation

- Material of conductor Cu
- Conductor

. fine wire
. finest wire

- Core and sheath insulations flexible.
- Line is designed for repeated use,

What is the difference between cables to be connected to mobile equipment and those for permanent installation?

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Examples of use of the lines for mobile devices and appliances

Kind of line		Room		In the open	Use
	dry	moist	wet
Light plastic hose cables	+	+	+		Lighting fittings, extension cables, refrigerators
Light rubber hose cables	+				Light heat appliances, irons, electric heat pads, extension cables
Medium plastic hose cables	+	+	+		Hand drills, industrial refrigerators, light X-ray units, office machines
Strong rubber hose cables	+	+	+	+	Construction equipment, machine tools

Figure 1 Light plastic hose cable (ready-made cable)

Figure 2 Light rubber hose cable (ready-made cable)

Figure 3 Light rubber hose cable with yarn wrapping (ready-made cable)

Figure 4 Medium-size rubber hose cable (covered)

Figure 5 Strong rubber hose cable

On what criteria does the selection and use depend of cables to be connected to mobile equipment?

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Plastic hose cables are allowed to be used for electric heat appliances only if it is absolutely impossible that the cable gets in touch with parts of the device that may be heated up to more than 85° Celsius.

For electric devices or appliances with plastic case no rubber hose cables must be used! Rubber contains an age-protecting agent, which passes over into the plastic material when it gets in contact with it and discolours it under the effect of light.