This standard specifies the voltage range of electrical installations. This standard applies to DC electrical installations with a nominal voltage of 1500V (including 1500V) or less and AC electrical installations with a power supply frequency of 60Hz or less and a nominal voltage of 1000V (including 1000V) or less. This standard is mainly used in conjunction with other standards for electrical installations, but can also be used when formulating requirements for electrical equipment. JB/T 5980-1992 Sections of electrical installations JB/T5980-1992 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Voltage range of electrical installations
JB/T5980-92
This standard refers to the International Electrotechnical Commission (IEC) Publication 449 "Voltage range of electrical installations in buildings" (1973 edition) and its first revision document in May 1979.
1 Subject content and scope of application
This standard specifies the voltage range of electrical installations. This standard applies to DC electrical installations with a nominal voltage of 1500V (including 1500V) or less and AC electrical installations with a power supply frequency of 60Hz or less and a nominal voltage of 1000V (including 1000V) or less. This standard is mainly used in conjunction with other standards for electrical installations, but can also be used when formulating requirements for electrical equipment. 2 Terminology
2.1 Nominal voltagenominalvoltage
Used to mark the voltage of an electrical installation or a part thereof. Note: ① The actual voltage and the nominal voltage may differ within the tolerance range. ② Transient voltages caused by switch operation, etc., or short-term voltage changes caused by abnormal operation caused by faults, etc. in the power supply system of the device are not considered.
2.2 Earthed systems
A system with one point (usually the neutral point for AC) directly grounded or grounded through a low impedance. 2.3 Ungrounded or non-effectively grounded system
A system without a grounding point or with one point (usually the neutral point for AC) grounded through a high impedance or grounded through an arc suppression coil. 2.4 Electrical equipment electrical equipment Any product used for power generation, transformation, transmission, distribution or consumption, such as motors, transformers, electrical appliances, measuring instruments, protection devices, wiring system equipment and electrical appliances. 2.5 Electrical installation electrical installation A combination of electrical equipment that achieves one or more specific purposes and has mutually coordinated characteristics. Voltage section
The voltage section of an electrical device is divided into two sections according to its nominal voltage: Section I and Section I. Section I: The nominal voltage of electrical equipment, AC does not exceed 50V; DC does not exceed 120V. Section I: The nominal voltage of electrical equipment, AC is higher than 50V, but not more than 1000V; DC is higher than 120V, but not more than 1500V.
: Note: ① The division of this voltage section does not exclude the possibility of some special standards proposing intermediate voltage values. ② Electrical equipment with an AC voltage level of 1140V used in coal mines and special occasions can be considered according to Section I. 3.1. AC voltage section
Divided according to the nominal voltage, as shown in Table 1:bZxz.net
For grounded systems, according to the root mean square value of the relative ground voltage and the phase-to-phase voltage; for ungrounded or non-effectively grounded systems, according to the root mean square value of the phase-to-phase voltage. Ministry of Machinery and Electronics Industry 1992-—07—17
1993—07-01Implementation
JB/T5980-92
Table 1. AC voltage section
Grounding system
Relative to ground
U≤50
50U≤600
Ungrounded or non-effective grounding system"
U≤50
50
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