GB 14287.2-2026 Electrical fire monitoring system - Part 2: Residual current electrical fire monitoring detector
1 Scope
This document defines the terms of residual current electrical fire monitoring detector, specifies the classification, technical requirements, inspection rules and marking, packaging, and describes the corresponding test methods.
This document applies to the design, manufacturing, and inspection of residual current electrical fire monitoring detectors (hereinafter referred to as "detectors") used in electrical fire monitoring system.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 9969 General principles for preparation of instructions for use of industrial products
GB 12978 Rules for test of fire electronic products
GB 14287 (all parts) Electrical fire monitoring system
GB/T 16838 Environmental test methods and severities for fire electronic products
GB/T 17626.2 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test
GB/T 17626.3 Electromagnetic compatibility - Testing and measurement techniques - Part 3: Radiated, radio-frequency, electromagnetic field immunity test
GB/T 17626.4 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient/burst immunity test
GB/T 17626.5 Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test
GB/T 17626.6 Electromagnetic compatibility - Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
GB/T 17626.8 Electromagnetic compatibility - Testing and measurement techniques - Power frequency magnetic field immunity test
GB/T 17626.11 Electromagnetic compatibility-Testing and measurement techniques-Part 11:Voltage dips, short interruptions and voltage variations immunity tests for equipment with input current up to 16 A per phase
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
residual current
effective value of the instantaneous current in a circuit composed of live conductors, such as phase and neutral conductors in an AC system or positive and negative polarity conductors in a DC system, calculated based on the vector sum (for AC) or algebraic sum (for DC)
3.1.1
AC residual current
effective value of the vector sum of the instantaneous currents in the circuit composed of phase conductors and the neutral conductor in an AC power distribution system
3.1.1.1
resistive residual current
AC residual current component where the phase is the same with the voltage
3.1.1.2
capacitive residual current
AC residual current component where the phase exceed the previous voltage by 90°
3.1.2
DC residual current
effective value of the algebraic sum of the instantaneous currents in the DC polarity conductor circuit in an AC power distribution system
3.1.2.1
steady-state residual current
DC residual current caused by long-standing insulation defects, equipment aging, or fixed leakage paths
Note: steady-state residual current has a relatively stable amplitude (fluctuation range ≤ ±5%), a long-term duration (lasting from minutes to permanent), and a spectrum concentrated in the low-frequency band (frequency ≤ 1 Hz).
3.1.2.2
dynamic residual current
DC residual current caused by interference factors such as sudden load changes, high-frequency disturbances, and harmonic currents from non-linear loads
Note: Dynamic residual current has rapidly changing amplitude (fluctuation range > ±20%), short duration (lasting from milliseconds to several seconds), and a wide frequency spectrum distributed across a broad range (frequency 1 Hz ~ 10 kHz).
3.2
residual current sensor
sensing device for monitoring residual current
Note: Residual current sensors mainly include AC residual current sensors, DC residual current sensors, and AC/DC residual current sensors.
3.3
signal processing unit
functional module used to receive the signal output from the residual current sensor, analyze the signal, and output information that can be used for alarm judgment
3.4
residual current electrical fire monitoring detector
device installed in AC and DC power distribution systems where the power neutral point is directly earthed or earthed via low resistance, used to monitor abnormal changes in residual current
Note: A residual current electrical fire monitoring detector consists of a residual current sensor (3.2) and a signal processing unit (3.3).
3.4.1
independent residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) suitable for use in power distribution systems, capable of independently monitoring changes in residual current and releasing audible and visual alarm signals
3.4.2
non-independent residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) suitable for use in power distribution systems, capable of monitoring residual current values and transmitting relevant information to electrical fire monitoring equipment
3.4.3
split-type residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) in which the signal processing unit and the residual current sensor are separate and not housed in the same device
3.4.4
integrated-type residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) in which the residual current sensor and the signal processing unit are integrated into a single device
3.4.5
AC residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) used for monitoring AC power distribution systems
Note: An AC type residual current electrical fire monitoring detector uses a residual current sensor (3.2) to collect, in real-time, the vector sum of the currents in each phase (including the neutral conductor) of the protected circuit. After analysis and calculation by the signal processing unit, an alarm is triggered when the residual current reaches a preset threshold.
3.4.6
DC residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) used for monitoring DC power distribution systems
Note: A DC type residual current electrical fire monitoring detector uses a residual current sensor (3.2) to collect, in real-time, the algebraic sum of the currents in the positive and negative conductors of the protected circuit. After analysis and calculation by the signal processing unit, an alarm is triggered when the residual current reaches a preset threshold.
3.4.7
AC/DC residual current electrical fire monitoring detector
residual current electrical fire monitoring detector (3.4) used for monitoring both AC and DC power distribution systems
Note: An AC/DC type residual current electrical fire monitoring detector is adaptable for use in both AC and DC power distribution systems. It uses a residual current sensor (3.2) to collect, in real-time, the corresponding type of residual current. After analysis and calculation by the signal processing unit, an alarm is triggered when the residual current reaches a preset threshold.
3.5
single-sensor electrical fire monitoring detector
electrical fire monitoring detector equipped with a single type of sensor, used to monitor changes in a specific physical quantity within a protected area
Note: Specific physical quantities mainly include, but are not limited to, residual current, temperature, arc fault, pyrolysis particles, insulation performance, etc.
3.6
combined multi-sensing electrical fire monitoring detector
electrical fire monitoring detector equipped with multiple sensors, capable of monitoring changes in two or more physical quantities within a protected area, such as residual current, temperature, arc fault, pyrolysis particles, insulation performance, etc.
3.7
system leakage capacitance
total distributed capacitance between all conductors and earth in the monitored power distribution system (including lines, electrical equipment, and earthing devices)
Note: System leakage capacitance reflects the capacitive coupling characteristics formed in the power distribution system due to factors such as insulation material polarization and parasitic cable-to-earth capacitance.
4 Classification
4.1 By working mode:
a) independent type;
b) non-independent type;
4.2 By the type of sensor:
a) single-sensor type;
b) combined multi-sensing type.
4.3 By the connection method between the sensing element and the signal processing unit:
a) split-type;
b) integrated-type.
4.4 By the type of current monitored:
a) AC type;
b) DC type;
c) AC/DC type.
5 Technical requirements
5.1 General
The monitors shall meet the requirements of this clause and be tested according to Clause 6 to verify the compliance with this clause. Among them, AC/DC detectors shall simultaneously meet the relevant technical requirements for AC type detectors and DC type detectors. Combined multi-sensing detectors shall also comply with the provisions of the relevant parts of GB 14287.
5.2 Appearance
The detector surface shall be free from corrosion, cracking, peeling, or blistering of the coating, free from obvious scratches, cracks, burrs, or other mechanical damage, and the fastened parts shall not loose.
5.3 Main component performance
5.3.1 General requirements
5.3.1.1 AC independent detectors shall be powered by a 220 V / 50 Hz AC power supply. DC independent detectors shall be powered by a DC power supply, and terminals shall be provided at the power input end.
5.3.1.2 Independent detectors can be connected to a maximum of 4 residual current sensors. On this basis, independent combined multi-sensing detectors can be simultaneously connected to a maximum of 4 sensors of other types.
5.3.1.3 The alarm setting value of the independent detector shall be set on the detector itself. The alarm setting value of non-independent detectors shall be set on the detector itself or on the electrical fire monitoring equipment connected to it. Setting operations shall be implemented by security means such as using special tools or password verification.
5.3.1.4 The manufacturer shall declare the connection type, wire diameter, and maximum connection cable length for the connection between the detector's sensor and the signal processing unit. In case of the maximum connection cable length, the performance of the detector shall meet the requirements.
5.3.1.5 The detector shall not have the function of controlling the power connection and disconnection of the protected circuit.
5.3.1.6 The detector shall not be connected to the protected circuit by means of electrical series connection.
5.3.1.7 Detectors with non-insulated material enclosures shall be provided with a protective earthing terminal and equipped with clear marking. The resistance between the protective earthing terminal and accessible non-insulated parts shall not exceed 0.5 Ω.
5.3.1.8 The non-metallic enclosures and terminal components of the detector shall comply with the combustion performance requirements specified in Annex A.
5.3.2 Indicator lights
5.3.2.1 The detector shall be equipped with an operation status indicator light, a fault status indicator light and an alarm status indicator light. The functions of the indicator lights shall be clearly marked in Chinese.
5.3.2.2 Indicator lights shall be color-coded, with red indicating the alarm status, yellow indicating the fault and supervisory status, and green indicating the normal status.
5.3.2.3 Indicator lights shall be clearly visible at a distance of 3 m directly in front of them under ambient lighting conditions ranging from 100 lx to 500 lx.
5.3.2.4 AC type detectors equipped with functions to measure voltage, current, and phase of the monitored power distribution system shall, according to the type of power distribution system they are adapted to, indicate the supervisory status using any of the following methods.
Contents
Foreword V
Introduction VII
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Technical requirements
5.1 General requirements
5.2 Appearance
5.3 Main component performance
5.4 Basic functions
5.5 Electrical parameter monitoring function
5.6 Alarm control function
5.7 Communication function
5.8 Repeatability
5.9 Conformance
5.10 Compatibility with multiple residual current sensors
5.11 High current surge adaptability
5.12 Harmonic adaptability
5.13 High-frequency load adaptability
5.14 Capacitive current suppression
5.15 Dynamic residual current adaptability
5.16 Insulation resistance
5.17 Leakage current
5.18 Dielectric strength
5.19 Electromagnetic compatibility
5.20 Voltage fluctuation
5.21 Operational stability
5.22 Mechanical environment endurance
5.23 Climatic environment endurance
5.24 Instructions for use
6 Test methods
6.1 General requirements
6.2 Inspection of appearance and main component performance
6.3 Monitoring alarm function test
6.4 Fault alarm function test
6.5 Electrical parameter monitoring function test (only for specimens with this function)
6.6 Alarm control function test (only for independent specimens)
6.7 Communication function test
6.8 Repeatability test
6.9 Conformance test (only for split-type specimens)
6.10 Test for compatibility of multiple residual current sensors
6.11 High current surge capability test
6.12 Harmonic adaptability test (only for AC type specimens)
6.13 High-frequency load adaptability test (only for AC type specimens)
6.14 Capacitive current suppression capability test (only for specimens with resistive residual current detection function)
6.15 Dynamic residual current adaptability test (only for DC type specimens)
6.16 Insulation resistance test
6.17 Leakage current test
6.18 Dielectric strength test
6.19 Radiated, radio-frequency,electromagnetic field immunity test
6.20 Test for immunity to conducted disturbances, induced by radio-frequency fields
6.21 Electrostatic discharge immunity test
6.22 Electrical fast transient/burst immunity test
6.23 Surge immunity test
6.24 Voltage dips, short interruptions and voltage variations immunity test
6.25 Power frequency magnetic field immunity test
6.26 Voltage fluctuation test (only for specimens powered by 220V/50 Hz AC supply)
6.27 Operational stability test
6.28 Vibration (sinusoidal) (in operation) test
6.29 Impact test
6.30 Low temperature (operation) test
6.31 Constant damp heat (operation) test
7 Inspection rules
7.1 Factory inspection
7.2 Type test
8 Marking and packaging
8.1 Product marking
8.2 Quality inspection marking
8.3 Marking durability
8.4 Packaging
Annex A (Normative) Burning behavior
A.1 General
A.2 Test
A.3 Requirements
Annex B (Normative) Residual current sensor
B.1 General requirements
B.2 Requirements
B.3 Test
Bibliography
