IEC 60364-7-740:2000 pdf download

IEC 60364-7-740:2000 pdf download.Electrical installations of buildings – Part 7-740: Requirements for special installations or locations – Temporary electrical installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses.
740.413.1.3 TN system
If the supply is a TN system, only the TN-S system shall be used.
740.413.1.5 IT system
Where an alternative system is available, an IT syslem shall not be used. IT systems, however. may be used for d.c. applications in accordance with IEC 62020. Where an IT system is used. permanent earth fault monitoring shall be provided.
740.413.1.6 Supplementary equlpotentlal bonding
740.413.1.6.1 In locations used for animals, supplementary equipotential bonding shall connect all exposed conductive parts and extraneous conductive parts which can be touched simultaneously to the protective conductor of the installation.
740.452 IsolatIon
740.462.1 Every separate temporary electrical installation for amusement devices and each distribution circuit supplying outdoor installations shall be provided with its own readily accessible and property identified means of isolation.
740.47 ApplIcation of protective measures for safety
740.471 Measures of protection agaInst electric shock
740471.1 Protection against electric shock in normal service
Protective measures against direct contact by means of obstacles (see clause 412.3 of IEC 60364.4-41) and by placing out of reach (see clause 412.4 of IEC 60364-4-41) shall not be used.
740,471.2 Protection against electric shock In case of a fault
Protective measures against indirect contact by non-conducting location (see clause 413.3 of IEC 60364-4-41) and by earth-tree equlpotential bonding (see clause 413.4 of IEC 60364-4-41) shall not be used.
740.48 Choice of protective measures as a function of external Influences
740.481 Selection of measures for protection against electric shock in relation to external Influences
740.481.1.4 For the application of the protective measure against indirect contact by automatic disconnection of supply, the conventional voltage limit in locations In which animals may be present is U1 . 25 V ac. r,m.s. or 60 V ripple-free d.c.. or the maximum disconnecting time is that Indicated in table 48A of IEC 60364-4-481
These conditions also apply to locations connected by conductive parts to the locations where animals may be present.
740,481.3 Choice of protective measures against Indirect contact
740.481.3.1.3 Automatic disconnection of Supply to the temporary structures shall be provided at the origin of the installation by RCDs with a rated residual operating current not exceeding 300 mA. These RCDs shall incorporate a time delay in accordance with IEC 60947-2 or be of the S-type in accordance with IEC 61008-1 or IEC 61009-1 for discrimination with RCDs protecting final circuits.
NOTE The recommendation tor additional protection relates to the increas.d risk ot damage to cables In tempoaary locations.
740.481.3.1.4 In order to prevent all supplies from being disconnected and causing danger (including non-electrical danger by the loss of motive power or lighting), It may be necessary to utalise more than one circuit.
740.482 Prot.ctlon against fir.
740.4822.8 A motor which Is automatically or remotely controlled and which Is not continuously supervised shall be fitted with a manually reset protective device against excess temperature.
740.5 Selection and erection of electrical equipment
740.51 Common rules
Switchgear and controlgear shall be placed in cabinets which can be opened only by the use of a key or a tool, except for those parts designed and Intended to be operated by ordinary persons (Code BA1), as defined in clause 322.1 of lEG 60364-3.
740.52 WirIng systems
740.521 Typ.. of wiring syst.ms
740521.6 Cables
Where appropriate, cables shall be of flexible construction.
Armoured cables or cables protected against mechanical damage shall be used wherever there Is a risk of mechanical damage.
All temporary power distribution cables shall be multicore, except for circuits above 125 A where single-core cables may be used.
All cables shall meet the requirements of IEC 60332.1.
NOTE Where enhanced pertormance is required, cables should meet Iii. requirements at IEC 60332-3: where low smoke Cabl.i are needed, the minimum recommended performance Is given in IEC 61034-2.
Cables shall have a minimum voltage designation of 450/750 V, except that, within amusement devices, cables and cords having a minimum voltage designation of 300/500 V may be used.
The routes of cables buried In the ground shall be marked at suitable intervals. Buried cables shall be protected against mechanical damage.