The specific requirements of this section apply to temporary electrical installations in the following projects: construction of new buildings; maintenance, renovation, extension or demolition of existing buildings; public utility projects; earthworks; other similar projects. This standard does not apply to electrical installations covered by IEC Publication 60621 or other electrical installations of similar nature to equipment used in open-pit mining. Partial modifications of buildings, such as extensions, overhauls or demolition, are similar to those used at the construction site during their construction, so such projects must be implemented in accordance with the provisions for temporary electrical installations. For administrative facilities (offices, cloakrooms, meeting rooms, canteens, restaurants, dormitories, toilets, etc.) at the construction site, the general provisions in Parts 1 to 6 of IEC Publication 60364 are applicable. GB 16895.7-2000 Electrical Installations in Buildings Part 7: Requirements for Special Installations or Locations Section 704: Electrical Installations at Construction and Demolition Sites GB16895.7-2000 Standard Download Decompression Password: www.bzxz.net

GE 16895.72000
This standard is a mandatory standard.
This standard is equivalent to IEC60364-7-704:1989 "Electrical installations in buildings and Part 7: Requirements for special installations or locations Section 704: Electrical installations in construction and demolition locations\ and its first revision (1999). IEC60364 "Electrical installations in buildings" is divided into the following 7 parts under the general title: Part 1: Scope, purpose and basic principles Part 2, Definitions
Part 3: Evaluation of general characteristics
Part 4: Safety protection
Part 5: Selection and installation of electrical equipment Part 6 Inspection
Part 7: Requirements for special installations or locations This standard is equivalent to Section 704 in Part 7 "Requirements for special installations or locations". The original text of the IEC standard quoted IEC60439-4:1990 "Low-voltage switchgear and controlgear Part 4: Particular requirements for complete sets of equipment for construction sites (ACS), but this standard is not listed in the referenced standards in the IEC preface. This situation is introduced in the preparation of this standard for explanation.
This standard was proposed by the State Machinery Industry Bureau. This standard is under the jurisdiction of the National Technical Committee for Standardization of Electrical Installations in Buildings. The responsible drafting unit of this standard: China Machinery and China Electric Design Institute. The main drafters of this standard are Feng Zongheng and He Xiangkun. This standard was first issued on October 17, 2000. GB16895.72000
IEC Preface
1) Formal resolutions or agreements of the IEC on technical issues are formulated by technical committees composed of national committees that are particularly concerned with these issues, and express international consensus on the issues involved as much as possible. 2) These resolutions or agreements are used internationally in the form of standards and are accepted by various national committees in this sense. 3) In order to promote international unification, IEC hopes that all national committees will use IEC standards in their respective national regulations as far as their domestic conditions permit. Any inconsistencies between IEC standards and corresponding national regulations should be clearly indicated in the national regulations as far as possible.
GB 16895.7-2000
IEC Introduction
This standard was proposed by IEC Technical Committee 64: Electrical Installations in Buildings. The text of this standard is based on the following documents: June Law
64(CO)166
Voting Report
64(CO)177
All information on the voting for this standard can be found in the voting report mentioned in the table above. This standard refers to the following IEC publications:
Publication 60364: Electrical installations of buildings, 60364-1: 1972 Part 1: Scope, purpose and basic principles 60364-21970 Part 2: Definitions
60364-3: 1977 Part 3: Evaluation of general characteristics 60364-4 Part 4: Safety protection
60364-5 Part 5: Selection and installation of electrical equipment 60364-6-61: 1986 Part 6: Inspection Chapter 61: Initial inspection 60364-7-706: 1983 Part 7: Requirements for special installations and locations Section 706 Narrow conductive locations 60621-1: 1987 Electrical installations in outdoor locations under severe conditions (including open-pit mines and quarries) Part 1: Scope and definitions 2IEC Amendment Document No. 1 Preface
This amendment was made by IEC TC64: Electrical installations in buildings. The text of this standard is based on the following documents: FDIS
64/1048/FDIS
Voting report
64/1063/RVD
In the voting report mentioned in the table above, all voting information on the voting for this amendment can be found. Usage Note:
17 The 1992 edition of this standard has been equivalently adopted as the national standard GB16895.1-1997 "Electrical installations in buildings Part 1: Scope, date and basic principles".
2] This standard has been non-equivalently adopted as the national standard GB 9089.1--1988 "Terms and definitions of electrical installations in outdoor locations under severe conditions". National Standard of the People's Republic of China
Electrical installations of buildings
Part 7 . Requireruents for special installetiuos or locatiogs--Section 704 :Construction and demolitlon site installations700.1Introduction
CB 16 895. 7 — 2 000
idt IEC 60364-7-704; 1989
The provisions of Part 7 are used to supplement, modify or cancel the general requirements in other parts of IEC Publication 60364. The numbers added after the specific section numbers in Part 7 correspond to the chapter, section or article numbers in IEC Publication 60364. If the chapter, section or article numbers of IEC Publication 60364 are not listed, it means that the general requirements of these articles are applicable in this part.
704 Electrical installations at construction and demolition sites
704.1 Scope of application
704.1.1 The specific requirements of this section apply to temporary electrical installations in the following projects: construction of new buildings
repair, renovation, extension or demolition of existing buildings; public utility projects!
earthmoving projects;
other similar projects.
This standard does not apply to electrical installations covered by IEC publication G0621 or other electrical installations of a similar nature to equipment used in open-pit mining.
Partial modifications of buildings, such as extensions, overhauls or demolition, are similar to construction sites during their construction, so such projects must be implemented in accordance with the provisions for temporary electrical installations.
For administrative facilities (offices, lockers, meeting rooms, canteens, restaurants, dormitories, toilets, etc.) at construction sites, the general provisions of IEC publication 60364 Parts 1 to 6 are applicable. NOTE: For special locations, more stringent requirements apply, for example, in narrow confined electrical spaces, the provisions of Section 706 shall apply. 704.1.5 In construction locations, fixed installations shall be limited to complete sets consisting of main control devices and basic protective devices (see 704.537).
Except for those designed in accordance with Chapter 52 (wiring systems), electrical installations on the load side shall be considered as mobile installations. 704.3—Evaluation of general characteristics
704.313 Power supply
704.313.1.3 Electrical equipment shall be consistent with the specific power supply to which it is supplied and shall contain devices that are connected only to the same installation, except for control or signal circuits and standby power supply incoming lines. Approved by the State Administration of Quality and Technical Supervision on October 17, 2000 and implemented on July 1, 2001

G9 16895. 72000
Note: A construction site may have several power supplies, including fixed or movable generator sets. 704.4 Safety protection
704.41 Protection against electric shock
704.413.1 Protection against automatic power cut-off
704.413.1.5 IT system
When using IT system, ground fault monitor shall be provided. 704.471 Measures for protection against electric shock
In addition to Section 471, the following provisions shall be observed: When the automatic power supply cut-off protection measures suitable for the grounding system are adopted to prevent indirect personal contact (7.1 of GB14821.11), the agreed contact voltage limit U, shall be: AC, RMS value 25V, or ripple-free DC value 60V Note: Reducing the system voltage can be used as a special application of the automatic power supply cut-off protection measures described in 7.1 of GB 14821.1 in the TN system. The maximum voltage of the AC system to be reduced is: the phase-to-phase voltage should not be greater than 110 V, for a single-phase system, the voltage to ground should not be greater than 55 V; for a three-phase system, the voltage to ground should not be greater than 63.5 V. In this case, the socket does not need to add the following protective measures. For the socket, a rated residual operating current of not more than 30 mA residual current operated protective device (6.5 of GB14821.1), or use safe extra-low voltage\power supply (5.1 of GB14821.1),Or use electrical isolation circuit 5, each removal socket is powered by an isolation transformer (7.5 in GB14821.1-1993). 704.5 Selection and installation of electrical equipment
704.51 General
704.511.1 All complete sets of power distribution equipment used in construction and demolition sites shall comply with the requirements of GB7251.4. 704.512.2 The enclosure protection level of fixed installation equipment and plug-in installation equipment (such as cable connectors) shall not be lower than IP44. The enclosure protection level of complete sets of equipment in construction sites shall comply with the provisions of GB7251.4. The enclosure protection level of other equipment shall be determined according to the situation affected by the external environment. 704.52 Wiring system
704.521.1.7.3 The number of lines should not cause the conductor terminal to be under tension, except for the terminal specially designed for this purpose. To avoid line damage, it is not advisable to install cable lines across the construction site road or sidewalk. When necessary, special protective measures should be taken to prevent the cable lines from mechanical damage and contact with construction machinery. 704.53 Switchgear and control equipment
Adoption instructions:
17GB14821.1-1993 "Electrical installations in buildings for electric shock protection" is equivalent to IEC.60364-4-41, 1992 "Electrical installations in buildings Part 4: Safety protection Chapter 41: Electric shock protection." 2] The term "agreed contact voltage" in this standard has been changed to "expected contact voltage" in the CB 14821. 1-1993 standard. 3] The measures to reduce the system voltage in the note have a voltage to ground of up to 63.5V, which is much higher than the limit of 50V of the safety extra-low voltage. The safety level is reduced, which is not conducive to personal safety. In [EC1200-704\Electrical Installation Guide Section 704: Electrical Installations in Construction and Demolition Sites”, it is stipulated that this voltage reduction measure is only considered when encountering harsh working or environmental conditions and SELV and PELV cannot be used, and its application conditions are limited.
4 Ting The term "safety extra low voltage" has been changed to "extra low voltage (ELV): SELV and PELV" in the GB14821.1-1993 "Electrical Installations in Buildings for Electric Shock Protection" standard. Due to the changes in the name and connotation of the term, this standard still uses "safety extra low voltage". 5] Electrical separation of cirruits), requiring the circuit to be separated by a number of devices or other measures to be taken to separate the circuit. The power supply should be supplied by an isolation transformer. The exposed conductive parts of the separated circuits shall not be connected to the exposed conductive parts or protective wires of other circuits. For details, see 7.5 in GB14821.1-1993.
6] GB7251.4-1998 Low-voltage complete switchgear and control equipment Part 4: Special requirements for complete equipment for construction sites (AC5)" is equivalent to IEC439-4.1 990&Low-voltage switchgear and control equipment Part 4: Special requirements for complete sets of equipment (ACS) for construction sites" and its first revision (1995)
704.537 Isolation and switching devices
GB16895.7—2000
At the power supply line end of each device, a complete set of equipment consisting of main control equipment and basic protective electrical appliances should be installed. One or more switches and isolators should be installed at the incoming cable end of each complete power supply equipment and each complete distribution equipment.
An emergency circuit breaker should be installed on the main power supply that supplies power to all electrical equipment to cut off all live conductors and eliminate danger when necessary.
The isolation and protection devices of the distribution circuit can be installed in the main or set of distribution equipment, or in the sub-set distribution equipment fed by the main complete distribution equipment.
The power isolation device on the incoming line should be able to ensure that it is in the disconnected position when disconnected (see 462.3) (for example, hanging it, or installing it in a lockable casing). ||tt ||The power supply of electrical equipment shall be implemented by a complete set of power distribution equipment, each of which shall include: - Overcurrent protection device,
~ - Indirect contact protection device:
- Socket.
The connection of the safety power supply and the backup power supply shall adopt an appliance that can prevent different power supplies from being interconnected and connected to the grid. 704.53B Plugs and sockets
The sockets shall be set according to the following requirements:
-Installed inside the complete set of equipment according to the requirements of 704.537; or -The sockets shall be installed on the outer wall of such complete set of equipment.3) (for example, hanging, or installing in a lockable casing).
The power supply of electrical equipment shall be implemented by a complete set of distribution equipment, each of which shall include: - Overcurrent protection device,
~ - Indirect contact protection device:
- Socket.
The connection of the safety power supply and the backup power supply shall adopt an appliance that can prevent different power supplies from being interconnected and connected to the grid. 704.53B Plugs and sockets bzxZ.net
The sockets shall be set according to the following requirements:
-Installed inside the complete set of equipment according to the requirements of 704.537; or -The sockets shall be installed on the outer wall of such complete sets of equipment.3) (for example, hanging, or installing in a lockable casing).
The power supply of electrical equipment shall be implemented by a complete set of distribution equipment, each of which shall include: - Overcurrent protection device,
~ - Indirect contact protection device:
- Socket.
The connection of the safety power supply and the backup power supply shall adopt an appliance that can prevent different power supplies from being interconnected and connected to the grid. 704.53B Plugs and sockets
The sockets shall be set according to the following requirements:
-Installed inside the complete set of equipment according to the requirements of 704.537; or -The sockets shall be installed on the outer wall of such complete sets of equipment.
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