Talk:Definition of standardised earthing schemes/Archive 1: Difference between revisions
| Line 20: | Line 20: | ||
---- | ---- | ||
In that case sentence related to TN-S system should be: | In that case sentence related to TN-S system should be: | ||
The TN-S system (5 wires) is obligatory for circuits with cross-sectional areas less than 10 mm2 '''OR''' for portable equipment. | The TN-S system (5 wires) is obligatory for circuits with cross-sectional areas less than 10 mm2 '''OR''' for portable equipment. | ||
Revision as of 09:22, 30 April 2010
Is the following sentence related to TN-C system correct with or without "OR"?
This system is not permitted for conductors of less than 10 mm2 OR for portable equipment.
IEC60343-5-54 PEN
To be precise, the IEC60364 states:
411.4.3 In fixed installations, a single conductor may serve both as a protective conductor and as a neutral conductor (PEN conductor) provided that the requirements of 543.4 of IEC 60364-5-54 are satisfied. No switching or isolating device shall be inserted in the PEN conductor.
543.4.1 A PEN conductor may only be used in fixed electrical installations and, for mechanical reasons, shall have a cross-sectional area not less than 10 mm2 in copper or 16 mm² in aluminium.
So TNC can not be used for portable equipment, and when used for fixed installation PEN shall have S>=10mm2 If active conductors' size is lower, it's usually cheaper to go to TNS. --Mathieu GUILLOT 08:42, 30 April 2010 (UTC)
In that case sentence related to TN-S system should be: The TN-S system (5 wires) is obligatory for circuits with cross-sectional areas less than 10 mm2 OR for portable equipment.
