1.0.1 This code is formulated with a view to ensuring personal and property safety, energy conservation, advanced technology, full function, economic rationality, reliable electrical installation as well as convenient installation and operation in the design of low-voltage electrical installations.
1.0.2 This code is applicable to the design of low-voltage electrical installations at 1000V AC power frequency in construction, extension and renovation engineering.
1.0.3 The design of low-voltage electrical installations shall not only meet the requirements of this code, but also comply with those in the current relevant ones of the nation.
2 Terms
2.0.1 Prospective touch voltage
The voltage between conductive parts which may be touched by human being and animals simultaneously where they haven't yet touched the conductive parts.
2.1.2 Conventional prospective touch voltage limit
The maximum value of prospective touch voltage which may exist continuously under specified external influence.
2.0.3 Direct contact
Electrical contact with live part by human being or animals.
2.0.4 Indirect contact
Electrical contact with live exposed conductive part under fault by human being or animals.
2.0.5 Protection against direct contact
Protection against electronic shock under no fault
2.0.6 Protection against indirect contact
Protection against electronic shock under a single fault
2.0.7 Additional protection
Protective measures other than protection against direct contact and indirect contact.
2.0.8 Arm's reach
The maximum range where human being can reach with hands, by virtue of no means, in any direction from any point on the surface where human being usually stands or acts.
2.0.9 Enclosure
The outer cover which can provide protection type and protection grade to adapt to expected application.
2.0.10 Protective barrier
A barrier for avoiding direct contact from normally possible approaching direction.
2.0.11 Protective obstacle
An obstacle for avoiding unintentional direct contact.
2.0.12 Electrical separation
Protective measures for insulating dangerous live parts against other electric loops and electric components as well as against earth, and for avoiding all contacts.
2.0.13 Protective separation
Separation of one circuit from other circuits through double insulation, reinforced insulation or basic insulation and electrical protection shielding.
2.0.14 Extra-low voltage
The voltage where the voltage between phases or phase-to-ground voltage is less than or equal to AC root mean square (RMS) value 50V.
2.0.15 SELV system
An electrical system, unearthed under normal conditions, whose voltage is less than or equal to extra-low voltage.
2.0.16 PELV system
An electrical system, earthed under normal conditions, whose voltage is less than or equal to extra-low voltage.
2.0.17 FELV system
An electrical system whose unsafe voltage for operation is less than or equal to extra-low voltage.
2.0.18 Equipotential bonding
A bonding among a few conductive parts to reach the equipotential.
2.0.19 Protective equipotential bonding
An equipotential bonding for safe purpose.
2.0.20 Functional equipotential bonding
An equipotential bonding for normal operation.
2.0.21 Main equipotential bonding
A bonding, in protective equipotential bonding, to connect such conductive parts as main protective conductor, main earthing conductor or main earthing terminal as well as metal piping and available metal structure inside building.
2.0.22 Supplementary equipotential bonding
A protective equipotential bonding to directly connect conductive parts with conductors so that their potentials is equal or close.
2.0.23 Local equipotential bonding
A protective equipotential bonding to connect conductive parts within a partial range.
2.0.24 Earth fault
An accidental conductive pathway between live conductor and earth.
2.0.25 Conduit
A round-section component where insulated conductor or cable may penetrate or get replaced.
2.0.26 Cable trunking
A closed shell, consisting of a base with movable cover, used for enclosing insulated conductor, cable and flexible wire.
2.0.27 Cable tray
A cable supporter with continuous chassis and side but without cover.
2.0.28 Cable ladder
A cable supporter with a series of transverse supporting members firmly fixed on longitudinal main supporting components.
2.0.29 Cable brackets
Spaced horizontal cable supporters with only one fixed end.
2.0.30 Mobile equipment
A kind of electrical equipment which is movable during operation or is easy to move from one position to another position where it is power-connected.
2.0.31 Hand-held equipment
Electrical equipment held in hand(s) during normal use.
2.0.32 Switching device
A device for making or breaking circuits.
2.0.33 Switch
A mechanical switching device which is capable of making, carrying or breaking current under normal working conditions or under overloading condition as well as capable of carrying current for a certain period under short-circuit conditions or other abnormal conditions.
2.0.34 Switch-disconnector
A switch capable of satisfying the isolation requirements of an isolator at the disconnected position.
2.0.35 Device for isolation
A device with isolation function.
2.0.36 Circuit-breaker
A mechanical switching electrical installation which is capable of making, carrying or breaking current under normal working conditions as well as capable of making and carrying current for a certain period and breaking current under such abnormal conditions as short-circuits
2.0.37 Mineral insulated cables
Cables, in the same metal sheath, consisting of one conductor or several conductors which are subject to compressed mineral power insulation.