GB 6830-2025 The tolerable limits of danger on telecommunication lines from power lines English, Anglais, Englisch, Inglés, えいご
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ICS 91.120.10
CCS H 57
National Standard of the People's Republic of China
GB 6830-2025
Replaces GB 6830-1986
The tolerable limits of danger on telecommunication lines from power lines
电信线路遭受强电线路危险影响的容许值
Issue date: 2025-10-31 Implementation date: 2026-11-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
Introduction
1 Scope
2 Normative Reference Documents
3 Terms and Definitions
4 Classification and Model Designation
4.1 Classification
4.2 Model Designation
5. Requirements
5.1 Appearance and Marking
5.2 Product Specifications
5.3 Shell
5.4 Fasteners
5.5 Rubber Sealing Ring
5.6 Vacuum level (negative pressure sealing)
5.7 Air Tightness Performance
5.8 Sealing Performance
5.9 Pressure Resistance
5.10 Bearing Torque
5.11 Flex joint deflection angle
5.12 Elongation Clearance
5.13 Low-Temperature Resistance
5.14 High-Temperature Aging Resistance
5.15 Resistance to Water Impact
5.16 Vibration Resistance Performance
5.17 Fire Resistance
5.18 Equivalent Length
6. Test Methods
7 Inspection Rules
7.1 Inspection Classification and Items
7.2 Sampling Methods
7.3 Inspection Result Judgment
8. Markings and Instructions for Use
8.1 Logo
8.2 User Manual
9 Packaging, Transport, and Storage
Appendix A (Normative) Groove Dimensions
Appendix B (Normative) Maximum Permissible Diameter of Branch Pipes
Appendix C (Informative) Grooved Pipe Fitting Structural Lengths
1 Scope
This document specifies the permissible values of hazardous voltages on telecommunication lines and hazardous currents flowing through the human body when telecommunication lines are exposed to hazardous effects from power lines.
This document applies to various types of AC power lines and AC electrified railway contact networks under the following conditions where they may cause hazardous effects on adjacent telecommunication lines:
a) Fault conditions of power lines:
Single-phase short-circuit grounding of a three-phase symmetrically neutral-point directly earthed power line;
Single-phase short-circuit grounding of a three-phase symmetrically neutral-point non-directly earthed power line;
Simultaneous two-phase short-circuit grounding at different locations of a three-phase symmetrically neutral-point non-directly earthed power line;
Short-circuit grounding of AC electrified railway contact network conductors;
Short-circuit grounding of asymmetric power line conductors.
b) Normal operation conditions of power lines:
Normal operation of AC electrified railway contact networks;
Normal operation of other asymmetric power lines.
2 Normative References
This document has no normative references.
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1 Hazardous effect
The voltage and current effects on telecommunication lines caused by electromagnetic induction from power lines, which may endanger personal safety, damage telecommunication lines or equipment, or cause building fires.
[Source: DL/T 5033—2023, 2.1.7, modified]
3.2 Power line
A general term for AC power lines and AC electrified railway contact networks.
Note: Transmits AC power at industrial frequency (50 Hz).
3.3 Electrified railway overhead contact system
An overhead conductor system that supplies electrical energy to locomotives via pantographs.
Note: Primarily consists of supports, foundations, support structures, and contact suspension.
[Source: GB/T 50262—2024, 17.3.1, modified]
3.4 Directly earthed neutral
A grounding method where the neutral point of a power system transformer is directly or indirectly grounded through low impedance.
3.5 Non-directly earthed neutral
A grounding method where the neutral point of a power system transformer is not grounded or is grounded through arc suppression coils or high impedance.
3.6 Telecommunication lines
Communication lines in the form of overhead or buried cables, overhead or buried optical cables, and wired broadcast (signal, power feed, user) lines.
3.7 Capacitive coupling
The phenomenon where the electric field generated by a charged line (source conductor) affects another line (affected conductor).
Note: Quantified by the capacitance between conductors and between each conductor and the ground.
3.8 Inductive coupling
The phenomenon where the magnetic field generated by a current-carrying line (source conductor) affects another line (affected conductor).
Note: Quantified by the mutual impedance between two conductors with a common grounding loop.
3.9 Resistive coupling
The phenomenon where current flowing from one conductor structure (source conductor) to ground affects another conductor structure (affected conductor).
Note: Quantified by the conductance between these conductors (structures).
3.10 Induced longitudinal electromotive force
The potential difference induced between any two points on a telecommunication line due to inductive coupling from currents in power lines and the ground.
[Source: DL/T 5033—2023, 2.1.12, modified]
4 Permissible Values of Hazardous Currents Caused by Capacitive Coupling
Under single-phase short-circuit grounding faults of three-phase symmetrically neutral-point non-directly earthed power lines, as well as during normal operation of AC electrified railway contact networks and other asymmetric power lines, the permissible current flowing through the human body due to capacitive coupling when touching a nearby telecommunication line conductor is 15 mA (rms).
5 Permissible Values of Hazardous Induced Magnetic Voltages Caused by Inductive Coupling
5.1 General Principle
Induced longitudinal electromotive force and induced voltage to ground are collectively referred to as induced magnetic voltages, both of which shall comply with the requirements of this document for permissible hazardous induced magnetic voltages.
5.2 Fault Conditions of Power Lines
5.2.1 Permissible Induced Magnetic Voltages on Telecommunication Cable Lines
The induced magnetic voltages on telecommunication cable cores shall comply with the following provisions:
a) When both ends of the telecommunication cable core are equipped with insulated transformers, or when one end is equipped with an insulated transformer and the other end is connected to low-impedance ground or to a grounded metal sheath/shield, or when surge protectors are installed at both terminals of all cable cores, the permissible induced magnetic voltages on telecommunication cable cores shall comply with Table 1.
Table 1 Permissible Hazardous Induced Magnetic Voltages on Telecommunication Cable Cores
Telecommunication Cable Remote Power Supply Method Permissible Voltage (V)
No remote power supply ≤0.6 UDC or ≤0.85 UAC
"Conductor-Ground" remote power supply
"Conductor-Conductor" remote power supply
Where:
UDC = DC test voltage between cable core and grounded sheath (V);
UAC = AC test voltage between cable core and grounded sheath (V);
Urs = Remote power supply voltage.
b) When the telecommunication cable cores do not meet the conditions specified in a), the permissible induced magnetic voltages on telecommunication cable cores shall comply with the following provisions:
The basic permissible voltage is 650 V.
The permissible induced magnetic voltages considering the duration of power line faults shall comply with Table 2.
Table 2 Permissible Hazardous Induced Magnetic Voltages
5.2.2 Permissible hazardous induced voltage on optical fiber cable lines
The hazardous induced voltage on optical fiber cable lines shall comply with the requirements of Table 3.
Table 3 Permissible hazardous induced voltage on optical fiber cable lines
5.3 Normal operation of power lines
The permissible hazardous induced voltage on telecommunication cable cores and optical cable metal components is 60V.
6 Permissible ground potential difference caused by resistive coupling
Under ground fault conditions of the power system, the permissible ground potential differences caused by resistive coupling between adjacent telecommunication cable cores, between cores and sheaths, between sheaths and earth, and between cores and earth, as well as the permissible ground potential rise on telecommunication grounding devices, shall comply with the provisions of Section 5.2.
