TLC Electrical Supplies

16th Edition (reference only) – NOW superseded by the 17th Edition IEE Regulations.

Installation control and protection

	3.1 - Introduction	3.5 - High temperature protection
	3.2 - Switching	3.6 - Overload currents
	3.3 - Isolation	3.7 - Protection from faults
	3.4 - Electric shock protection	3.8 - Short circuit and overload ------- protection

3.8.1 - Combined protection

3.8.2 - Current limited by supply characteristic

3.8.3 - Protection omitted

3.8.4 - Protection of conductors in parallel

3.8.5 - Absence of protection

3.8.6 - Discrimination

3.8.2 - Current limited by supply characteristic

If a supply has a high impedance, the maximum current it can provide could be less than the current carrying capacity of the cables in the installation. In such a case, no overload or short circuit protection is required.

This situation is very unlikely with a supply taken from an Electricity Company, but could well apply to a private generating plant.

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Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press Click Here to order your Copy.

Click here for list of abbreviations