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This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization—Part 1: Structure and drafting of standards.
This standard was proposed by China Electrical Equipment Industry Association.
This standard is under the jurisdiction of the National Technical Committee on Low-voltage Electrical Apparatus of Standardization Administration of China (SAC/TC 189).
Specific protective devices for
low-voltage surge protective devices
1 Scope
This standard specifies the service conditions, preferred values, classification, markings and other product information, technical requirements and test methods for specific protective devices for low-voltage surge protective devices.
This standard applies to specific protective devices for low-voltage surge protective devices in systems with AC frequency of 50Hz or 60Hz, and rated voltage not exceeding 440V (phase to phase), hereinafter referred to as the “specific protective device” or “SSD”.
Note: This standard may apply to specific protective devices for the surge protective devices (SPDs) intended for AC rated voltage not exceeding 1000V (rms) or DC voltage not exceeding 1500V.
For the purposes of this standard, the specific protective devices are mainly based on circuit breaker technology and are suitable for overcurrent protection of voltage-limiting SPDs.
The specific protective devices covered by this standard are suitable for isolation.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 4208-2017 Degrees of protection provided by enclosure (IP code)
GB/T 5023
(all parts) Polyvinyl chloride insulated cables of rated voltages up to and including 450/750V
GB/T 5169.10-2017 Fire hazard testing for electric and electronic products—Part 10: Glowing/hot-wire based test methods—Glow-wire apparatus and common test procedure
GB/T 5169.11-2017 Fire hazard testing for electric and electronic products—Part 11: Glowing/hot-wire based test methods—Glow-wire flammability test method for end-products (GWEPT)
GB/T 10963.1-2005 Electrical accessories—Circuit-breakers for over-current protection for household and similar installation—Part 1: Circuit-breakers for a.c. operation
GB/T 16927.1 High-voltage test techniques—Part 1: General definitions and test requirements
GB/T 18802.1-2011 Low-voltage surge protective devices—Part 1: Surge protective devices connected to low-voltage power distribution systems—Requirements and tests
3 Terms and definitions
For the purposes of this standard, the following terms and definitions and those given in GB/T 18802.1-2011 and GB/T 10963.1-2005 apply.
3.1
specific protective devices for low-voltage surge protective devices (SSD)
external detachment device intended for surge protective devices (SPDs) in low-voltage power supply systems, which can withstand the expected surge current at the place where the protected SPD is installed, and can cut off the over-current at power frequency caused by SPD failure and is characterized by actuation with small current at power frequency
3.2
rated operational voltage
Ue
AC voltage rms specified by the manufacturer that can be continuously applied to the specific protective device
3.3
rated insulating voltage
Ui
voltage value related to dielectric test voltage and creepage distance specified by the manufacturer. Unless otherwise specified, the maximum rated voltage of the specific protective device shall not exceed the rated insulating voltage.
3.4
residual voltage
peak voltage generated between the terminals of the specific protective device when an impulse current flows through
3.5
limiting voltage
maximum peak voltage measured between the terminals of the specific protective device when an impulse of the specified waveform and amplitude is applied
4 Service conditions
4.1 Ambient air temperature range
The ambient air temperature shall not exceed +40°C, and the average temperature over 24h shall not exceed +35°C.
The lower limit of ambient air temperature is -5°C.
The specific protective device subject to an ambient air temperature higher than +40°C or lower than -5°C shall adopt special design or be used according to the data provided in the manufacturer's brochure.
Note: The performance of the specific protective device beyond this temperature range is subject to agreement between the manufacturer and the user.
4.2 Altitude
The altitude of the installation site generally shall not exceed 2000m.
For specific protective devices installed at higher altitudes, the reduction of dielectric strength and air cooling effect must be considered. The specific protective device expected to be used under such condition shall adopt special design or be subject to the agreement between the manufacturer and the user. The data given in the manufacturer's brochure may replace such agreement.
4.3 Atmospheric conditions
The air shall be clean and have a relative humidity not exceeding 50% at the maximum temperature of +40°C.
A higher relative humidity is permitted at lower temperatures, e.g. 90% at +20°C.
Appropriate measures, e.g. laying a drain, shall be taken against moderate condensation that may occasionally occur due to temperature changes.
Note: For outdoor specific protective devices used in places affected by weather, the service environment is subject to agreement between the manufacturer and the user.
4.4 Installation conditions
The specific protective device shall be installed according to the manufacturer's instructions.
5 Preferred values
5.1 Impulse current Iimp for Class I tests
5kA, 10kA, 12.5kA, 15kA, 20kA, 25kA
5.2 Nominal discharge current In for Class II tests
1kA, 1.5kA, 2kA, 2.5kA, 3kA, 5kA, 10kA, 15kA, 20kA, 30kA, 35kA, 40kA, 50kA, 60kA
5.3 Open circuit voltage Uoc for Class III tests
0.1kV, 0.2kV, 0.5kV, 1kV, 2kV, 3kV, 4kV, 5kV, 6kV, 10kV, 20kV
5.4 Rated operational voltage Ue
230V
Note: In this standard, where 230V is involved, it can be understood as 220V or 240V.
5.5 Rated impulse withstand voltage Uimp
The rated impulse withstand voltage of the specific protective device shall not be less than 4kV.
Note: The specific protective device used in conjunction with an SPD for the level of the power inlet side shall have a rated impulse withstand voltage not less than 6kV.
5.6 Rated insulating voltage Ui
The rated insulating voltage of the specific protective device is the voltage specified by the manufacturer that is related to the dielectric test voltage and the creepage distance.
Unless otherwise specified, the rated insulating voltage is the maximum rated voltage of the specific protective device. In no case shall the maximum rated voltage exceed the rated insulating voltage.
5.7 Rated short-circuit capacity
1500A, 3000A, 4500A, 6000A, 10 000A, 15 000A, 20 000A, 25 000A, 35 000A, 50 000A, 65 000A, 100 000A
5.8 Minimum actuating current
5.8.1 Minimum deferred actuating current Id (optional)
0.5A, 1A, 2A, 3A, 5A
5.8.2 Minimum instantaneous actuating current Ii
0.5A, 1A, 3A, 5A, 10A, 15A
6 Classification
6.1 The specific protective devices are classified by test class of the SPD used in conjunction as follows:
—specific protective device for the SPDs subject to Class I tests;
—specific protective device for the SPDs subject to Class II tests;
—specific protective device for the SPDs subject to Class III tests.
Note: The same specific protective device can be used in conjunction with SPDs of multiple test classes.
6.2 The specific protective devices are classified by installation method as follows:
—surface-mounted specific protective device;
—flush-mounted specific protective device;
—panel-mounted specific protective device, also known as distribution panel mounted.
Note: All these specific protective devices can be installed on mounting rails.
6.3 The specific protective devices are classified by application as follows:
—specific protective device for indoor use;
—specific protective device for outdoor use.
Note: A specific protective device that is installed in an outdoor housing or protective cover is considered as specific protective device for indoor use.
6.4 The specific protective devices are classified by accessibility as follows:
—accessible specific protective device;
—inaccessible specific protective device.
Note: The accessible specific protective device means that it is accessible to non-professionals in whole or in part, and once it is installed, its cover or housing can be opened without use of tools. The inaccessible specific protective device means that it is inaccessible to non-professionals or is installed beyond the accessible reach, e.g. on an overhead wire, or placed in a housing that, once installed, can only be opened with tools.
6.5 The specific protective devices are classified by number of poles as follows:
—one-pole specific protective device;
—two-pole specific protective device;
—three-pole specific protective device;
—four-pole specific protective device.
7 Marking and other product data
7.1 Marking contents
Each specific protective device shall be marked with the following contents in a durable way:
a) manufacturer's name and trademark;
b) model, catalog number or serial number;
c) rated voltage;
d) test class and discharge parameters, which shall be close to each other:
Class I test: , Iimp and the unit kA;
Class II test: , In and the unit kA;
Class III test: , Uoc and the unit kV.
e) minimum deferred actuating current (optional);
f) minimum instantaneous actuating current;
g) rated short-circuit capacity, expressed by A;
h) wiring diagram, unless the correct wiring method is conspicuous;
i) degree of protection, if not IP20;
j) rated impulse withstand voltage Uimp, if not 4kV;
k) voltage protection level Up.
One specific protective device may be attributed to more than one test class, e.g. Class I test and Class II test . In this case, the test requirements of all declared test classes shall be implemented. If the manufacturer declares only one voltage protection level, the highest voltage protection level shall be marked.
If the manufacturer declares the minimum deferred actuating current, the corresponding actuating time shall be given in the instructions.
7.2 Other product data
The manufacturer shall provide the maximum continuous operational voltage Uc of the SPD applicable to the SSD in the instructions.
If the above data cannot be marked completely due to limited space, they be marked on the side and back of the specific protective device, and the content of h) may be marked inside the cover that must be opened when the power cord is connected. Any other data not marked shall be given in the documents provided by the manufacturer.
If the protection degree marked on the specific protective device is higher than IP20 defined in GB/T 4208-2017, no matter which installation method is adopted, it shall meet the requirements of 7.1. If the higher degree of protection is only achieved by using specific installation methods and/or specific accessories, e.g. terminal cover and housing, it shall be specified in the manufacturer's documents.
The open position of the specific protective device shall be marked with the symbol “O.OFF”, and the make position shall be marked with the symbol “|.ON”. As the specific protective device is installed, these markings shall be clearly legible.
If it is necessary to distinguish between the power supply terminal and the load terminal, they shall be clearly marked, e.g. with the power supply and load located near the corresponding terminals or with the arrow indicating the direction of electric power.
The markings shall be indelible and clearly legible, and shall not be located on screws, washers or other movable parts.
Compliance is checked by inspection and the test specified in 9.3.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Service conditions
5 Preferred values
6 Classification
7 Marking and other product data
8 Technical requirements
9 Type test
Annex A (Normative) Test procedures of conformity verification and number of specimens submitted
Annex B (Normative) Routine tests
Annex C (Normative) Limiting voltage of series circuit between specific protective device and SPD
Bibliography
