Some standard content:
ICS47.020.60
China Mechanical Industry Standard JB/T 6329—2002
Replaces JB/T6329—1992
JB/T7817—1995
Marine low-voltage fuses
Low-voltagefuses inship
2002-07-16 Issued
2002-12-01 Implementation
Issued by the State Economic and Trade Commission of the People's Republic of China Foreword
1 Scope
2 Normative references
3 Terms and definitions, symbols, codes
3.1 Terms and definitions
3.2 Symbols
3.3 Codes.
4 Classification, model,
Fuse characteristics
Characteristics of fuses
Rated voltage,
Rated current,
Rated frequency
Rated power dissipation of fuse-link and fuse holder and rated power acceptance size or dimensions
Normal working conditions and installation conditions
Normal working conditions,
Normal working of fuses Conditions
Pollution level
Installation category (overvoltage category)
Use category,
Structure and performance.
7.1 Structural requirements..
Performance requirements,
8 Test methods
Appearance inspection..
Dimension inspection,
Measurement of fuse resistance value
Verification of structural requirements,
Test Certification performance requirements
Inspection rules
Test and inspection classification of fuses
Type test,
Factory test..
Special test.
JB/T6329—2002
JB/T6329—2002
Marking, packaging, transportation and storage
Installation, maintenance and operating instructions.
Transportation and Storage
Others,
Spare parts and spare parts
Warranty period,
Overload curve and time-current characteristics of "a" fuse Normal working conditions
Insulation resistance value
Table 3 Appearance requirements of metal plating parts
Salt spray test cycle..
Rated impulse withstand voltage,
Test voltage,
Contact and terminal temperature rise limit△t...Overload test requirements
Agreed time and agreed current of "gG" and "gM" fuses Threshold value of specified pre-arcing time of "gG" and "gM" fuses, agreed cable current carrying capacity
Load conductor current carrying capacity,
Strike action verification,
Breaking capacity test parameters of AC fuses Breaking capacity test parameters of DC fuses Maximum arc voltage.
"gG" and Pre-arc t value of "gM" fuse 0.01Table 18
Vibration test parameters
Full set of fuse items and number of tested fusesTest items and number of tested fuses for the minimum rated current fuse in the same fuse seriesType test items and number of tested fuses for other rated current fuses between the maximum and minimum rated current in the same fuse series
Table 22 Complete test items of fuse holders and number of tested fuse holders.16
JB/T6329--2002
This standard is based on GB/T3783-1994 "Basic requirements for marine low-voltage electrical appliances" and GB13539.1-1992 "Basic requirements for low-voltage fuses" to revise JB/T6329-1992 "Marine low-voltage fuses" and JB/T7817-1995 "Marine filled enclosed tube fuses".
Compared with JB/T6329-1992 and JB/T7817-1995, the main changes of this standard are as follows: The writing format is in accordance with the provisions of GB/T1.1-2000 and GB/T1.2-2002: specific provisions are made for the range of AC and DC rated voltage values; - consistent with GB/T13539.1~2-1992, GB/T13539.4-1992 and GB/T13539.5-1999, the classification according to fuse structure is changed to classification according to the use object and protection content of the fuse and classification according to the breaking range and use category of the fuse body: 4.2 Product model and its meaning is changed to the method of compiling fuse model and its meaning shall comply with the provisions of GB/T9613-1988\. Chapter 5 Characteristics of fuses is supplemented.
According to GB/T3783-1994, the pollution level and installation category clauses of fuses applicable to marine environments and occasions are supplemented. In Chapter 7, Structure and Performance, the basic requirements for marine low-voltage electrical appliances in accordance with GB/T3783-1994 are compiled. In the 7.2.2 dielectric performance clause, the rated impulse withstand voltage test requirements are introduced to make the electrical clearance requirements more reasonably matched with the marine environment.
This standard replaces JB/T6329-1992 and JB/T7817-1995. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of Shanghai Electric Science Research Institute. This standard is drafted by Shanghai Electric Science Research Institute, and Shanghai Electric Ceramics Factory, Ningbo Switch Factory, and Shanghai Jinshan Electric Factory participated in the drafting. The main drafters of this standard are: Chen Lanjin, Zhuang Huogeng, Lin Haiou, Lu Baofa, Fang Tiantong, Hao Qingyun. This standard was first issued in 1992.
1) GB/T9613-1988 has been replaced by SJ/T11005-1996. 1 Scope
Marine low-voltage fuses
JB/T6329-2002
This standard specifies the characteristics, technical requirements, test and inspection rules of marine low-voltage fuses (hereinafter referred to as fuses) and their components (fuse base, fuse carrier, fuse element). This standard applies to fuses equipped with enclosed current-limiting fuses with a rated breaking capacity of not less than 6kA. The fuse is used as circuit protection for ships and offshore installations with a rated AC voltage not exceeding 690V and a rated DC voltage not exceeding 1000V. This standard does not apply to miniature fuses.
2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to investigate whether the latest versions of these documents can be used. For any undated referenced document, the latest version applies to this standard. GB/T2423.1—2001 Environmental testing for electric and electronic products Part 2: Test methods Test A: Low temperature (idtIEC60068-2-1:1990) GB/T2423.2--2001 Environmental testing for electric and electronic products Part 2: Test methods Test B: High temperature (idtEC60068-2-2:1974)
GB/T2423.4—1993wwW.bzxz.Net
60068-2-30:1980)
GB/T2423.16 —1999
60068-2-10:1988)
Basic environmental testing procedures for electric and electronic products Test Db: Cyclic damp heat test method (eqvIEC ... Product environmental testing Part 2: Test methods Test Kb: Salt, alternating (sodium chloride solution) (idtEC60068-2-52:1996) GB/T2828*-1987 Batch inspection counting sampling procedures and sampling tables (applicable to inspection of continuous batches) Periodic inspection counting sampling procedures and sampling tables (applicable to inspection of production process stability) GB/T28291987)
GB/T3783-1994 Basic requirements for marine low-voltage electrical appliances (negEC60971-1) GB/T420 7-1984 Determination method of comparative tracking index and resistance tracking index of solid insulating materials under humid conditions (neqIEC60112:1979)
GB/T4942.2-1993
Degree of protection of low-voltage electrical enclosures (eqvIEC60947-1:1988) GB/T4988--1985 Rated frequency, rated voltage and rated current of electrical products for ships and offshore oil platforms (neqIEC60038:1977) GB/T5465.21996
Graphic symbols for electrical equipment (idt 正 C60417:1994) GB/T6994—1986General provisions for marine electrical equipment (neqEC60092-101:1980) GB/T70941986
Vibration (sinusoidal) test method for marine electrical equipment (neq 正 C60092)Model compilation method for marine low-voltage switchgear and electric control equipment GB/T9613—1988
GB/T13384—-1992
GB13539.1--1992
GB13539.21992
GB13539.4—1992
General technical conditions for packaging of electromechanical products
Basic requirements for low-voltage fuses (neq EC60269-1:1986) Low-voltage fuses Supplementary requirements for fuses used by professional personnel (negIEC60269-2:1986) Low-voltage fuses Supplementary requirements for fuses used for protection of semiconductor devices (neqEC60269-4:1986) GB/T13539.5-1999 Low-voltage fuses Part 3: Supplementary requirements for fuses used by unskilled personnel (fuses mainly used for household and similar purposes) Examples of standardized fuses (idtEC60269-3-1:1994) JB/T6329-2002
3 Terms and definitions, symbols, codes
Terms and definitions
The terms and definitions established in GB/T13539.1-1992 and GB/T3783-1994 apply to this standard. 3.2 Symbols
tn: Ambient air temperature:
fe: Fluid ambient temperature:
t: Fuse component temperature:
I: Rated current of fuse link;
Iar: Conventional non-fusing current:
I: Conventional fusing current:
1: Current indicating rated breaking capacity:
12: Current with approximately maximum arc energy during test: 13, 14, 15: Verify that the fuse is within the small overcurrent range Test current to check whether it can work reliably: At: Temperature rise limit:
Ate: Temperature rise of internal fluid in contact with fuse parts (relative to ambient air temperature); U: Rated voltage:
leh: Characteristic current:
l: Maximum value of cut-off current:
I: Expected current:
I: Current carrying capacity of double-core load wire:
ko, ky, k2: "a" fuse overload current relative to the rated current, multiples. 3.3 Code
g: Fuse with full range breaking capacity;
a: Fuse with partial range breaking capacity: G: Fuse for general use;
M: Fuse for protecting motor circuit.
4 Classification and model
4.1 Classification
4.1.1 According to the use object and protection content of the fuse, it is divided into: a) Fuses used by full-time personnel:
b) Fuses used by unskilled personnel:
c) Fuses used to protect semiconductor devices. 4.1.2 According to the breaking range and use category of the fuse, it is divided into: a)
"gG" indicates a fuse with a full range of breaking capacity for general use; b) "gM" indicates a fuse with a full range of breaking capacity for protecting the motor circuit: c) "aM" indicates a fuse with a partial range of breaking capacity for protecting the motor circuit: d) "gD" indicates a time-delay fuse with a full range of breaking capacity: "gN" indicates a non-time-delay fuse with a full range of breaking capacity. e)
4.1.3 According to the example of standardized fuses, they are divided into: 4.1.3.1 Fuses used by professional personnel: a)
Knife contact fuses;
Bolt connection fuses:
Round simple cap fuses:
Offset knife contact fuses:
"gD" and "gN" fuses.
Fuses used by unskilled personnel:
D type fuses:
A type round tube fuses:
B type round tube fuses:
C type round tube fuses:
Pin fuses:
Round tube fuses for plugs.
4.2 Model
The model compilation method and its meaning of the fuse shall comply with the provisions of GB/T9613-1999. 5 Fuse characteristics
Characteristic composition of the fuse
Fuse holder
Rated voltage:
Rated current:
Current type and rated frequency:
Rated receiving power;
Dimension or size:
Number of poles;
Peak withstand current.
Fuse link
Rated voltage:
Rated current:
Current type and rated frequency:
Rated dissipated power;
Time-current characteristic:
Breaking range:
Rated breaking capacity:
Cut-off current characteristic:
Characteristics:
Dimensions or sizes.
5.1.3Full fuse
Protection level shall be in accordance with the provisions of GB/T4942.2-1993 and selected with reference to 4.4 of GB/T3783-1994. 5.2Rated voltage
5.2.1Rated voltage value of AC fuse
115V, 220V, 380V, 440V, 600V, 660V2*, 690V. 5.2.2 Rated voltage of DC fuse: 24V, 110V, 220V, 440V, 750V, 800V2, 1000V. 2》Applicable to fuses for offshore installations.
JB/T6329—2002
JB/T6329—2002
The rated voltage of the fuse-link may be different from the rated voltage of the fuse holder into which the fuse-link is installed. The rated voltage of the fuse is the lowest value of the rated voltage of its components (fuse holder, fuse). The selection of other values shall be negotiated by the user and the manufacturer. 5.3 Rated current
5.3.1 Rated current value of fuse link:
The rated current of fuse link is in A and should be selected from the following values: 2, 4, 6.3 (6), 8, 10, 12.5 (12), 16, 20, 25, 31.5 (32), 40, 50, 63, 80, 100, 125, 160200, 250, 315, 400, 500, 630 , 800, 1000, 1250. 5.3.2 Rated current value of fuse holder: It should be selected from the rated current series of fuse body. For "gG" and "aM" fuses, the rated current of fuse holder indicates the maximum rated current of the matching fuse body.
5.4 Rated frequency
The rated frequency of the fuse is 50Hz or 60Hz. When the frequency is not specified, it is between 45Hz and 62Hz. 5.5 Rated dissipation power of fuse link and rated power acceptance of fuse holder If the "Fuse Standard" 3" does not specify, the rated dissipation power of fuse link shall be specified by the manufacturer. Under the specified test conditions, the dissipation power of fuse link shall not exceed the specified value. If the "Fuse Standard" does not specify, the rated power acceptance of fuse holder shall be specified by the manufacturer. The rated power acceptance is the maximum power dissipation that the fuse holder can withstand under the specified test conditions without exceeding the specified temperature rise. 5.6 Dimensions or sizes
See GB/T13539 "Fuse Standard"
Normal working conditions and installation conditions
6.1 Normal working conditions
The fuse shall operate normally under the environmental conditions specified in Table 1. Table 1 Normal working conditions
Environmental factors
Maximum ambient air temperature ,
Minimum ambient air temperature,
Influence of humid air at sea
Influence of salt spray
Influence of oil mist
Influence of mold
Impact?
Normal working environment
-25℃b
≤22.5°
40℃ Mainly applicable to electrical appliances used in coastal and inland ships, special consideration should be given to places above 45℃. . Mainly applicable to electrical appliances installed on open decks and open deck cabins without insulation measures. Special consideration should be given to places below -25℃. . Refers to the impact generated during normal operation of the ship. 3) "Fuse sub-standard" refers to GB/T13539.2-1992 low-voltage fuses Part 2: Supplementary requirements for fuses used by full-time personnel (mainly used for industrial fuses), GB/13539.5-1999 Low-voltage fuses Part 3: Supplementary requirements for fuses used by unskilled personnel (mainly for household and similar purposes) Standardized fuse examples, and GB13539.4-1992 Low-voltage fuses and other semiconductor device protection fuses Supplementary requirements. 6.2 Normal working conditions of fuses
Fuses should work normally under the following specified voltage and frequency changes: JB/T6329--2002
a) The voltage change of the AC power supply is 10%~10% of the rated voltage, and the frequency change is 5% of the rated frequency: b) The voltage change of the DC power supply is 10%~10% of the rated voltage c) The voltage change of the battery power supply is 20% of the rated voltage (for fuses that also work when charging the battery, it is 1030%~25%). 6.3 Pollution level
The pollution level of the fuse is generally level 3.
6.4 Installation category (overvoltage category)
a) Class IIIII (distribution level):
b) Class IV (power supply level).
6.5 Use category
For use category, see 4.1.2 of this standard.
7 Structure and performance
7.1 Structural requirements
7.1.1 Replacement of fuse-links
The fuse-links should be easily and safely replaced. 7.1.2 Connections including terminals
Fixed connections should be able to maintain the necessary contact pressure under use and operating conditions. The terminals should not rotate or shift when the connecting screws are tightened, and the connected conductors should not move. The parts that clamp the conductors should be metal and their shape should not damage the conductors. The structure of the terminals should ensure good electrical contact and a certain current-carrying capacity. The conductive metal parts should have sufficient mechanical strength.
7.1.3 Fuse contacts
The contacts of the fuses shall have the necessary contact pressure under the conditions of use and operation, especially under the conditions specified in 7.2.5 of this standard. During the disconnection process, the electric force shall not be sufficient to damage the electrical connection between the fuse base and the fuse carrier, between the fuse carrier and the fuse, and between the fuse and the fuse base or other supporting parts. The structure and material of the fuse contacts shall ensure that they can maintain good contact under normal use and installation conditions, repeated loading and unloading, and long-term non-loading and unloading conditions.
The copper alloy fuse contacts shall not crack. 7.1.4 Materials
The insulating parts of the fuses shall be made of durable, flame-retardant, moisture-resistant and resistant materials, and toxic materials or materials that can release toxic gases shall be avoided as much as possible. In addition to having good corrosion resistance, metal parts shall have reliable protection. The suitability of the selected materials can be verified by the following tests, which can be carried out on the fuse or its parts. 7.1.4.1 Aging resistance of elastic parts
Elastomer parts of fuses made of rubber, polyvinyl chloride (PVC) or similar materials (such as gaskets, sealing rings, films and screw cap gaskets) should have aging resistance. The test method for verifying aging resistance is specified in 8.5.1 of this standard. 7.1.4.2 Moisture and heat resistance test
The fuse shall have moisture and heat resistance performance, that is, after the product has been subjected to 55℃, 2 cycles of alternating moisture and heat test, the insulation resistance shall not be lower than the requirements of Table 2. Table 2 Insulation resistance value
Rated insulation
Voltage V
U≤60
Insulation resistance table
Voltage level V
Measured with a 1000V insulation resistance meter
Note: When the rated insulation voltage is greater than 660V, before moisture and heat test
Insulation resistance MQ
After moisture and heat test
JB/T63292002
7.1.4.3 Heat resistance
The fuse shall have no harmful damage at the highest temperature that may be reached under normal working conditions. The verification of heat resistance shall be carried out in accordance with test method 8.5.3.
7.1.4.4 Resistance to mildew
The fuse shall have resistance to mildew. After mildew growth test, the area of the insulating parts exposed to the air shall not exceed the second grade of mildew specified in GB/T2423.16-1999 or the index agreed by the factory, user and ship inspection department. 7.1.4.5 Resistance to salt spray
The fuse shall have resistance to salt spray. After salt spray test, the appearance change of the metal electroplated parts exposed to the air shall meet the requirements of Table 3. The salt spray test cycle shall meet the requirements of Table 4. If the fuse is actually used with a shell, the test cycle shall be 96h when the salt spray test is carried out with the shell.
Table 3 Appearance requirements for metal electroplating parts
Coating category
Copper + dart + chromium
Low saw bronze + chromium
Nickel + chromium
Nickel or high tin bronze
Silver, gold
Salt spray test cycle
7.1.4.6 Resistance to abnormal heat and fire hazards Base metal
Copper and copper alloys
Copper and steel alloys
Copper and copper alloys
Table 4 Salt spray test cycle
Qualification requirements
No brown rust on the main surface
No light green corrosion on the main surface
No light green corrosion on the main surface
No gray or light green corrosion on the main surfaceNo gray black corrosion on the main surface
No steel green on the main surface
Suitable occasions
Fuse installed in the ship's machinery room or other general compartmentsFuse installed on the open deck
Insulating material parts may be subjected to thermal stress due to electrical effects, and insulation deterioration may damage electrical safety. The insulating parts of the fuse should be subjected to the assessment of the burning test.
7.1.4.7 Flame retardant performance
The insulating material of the fuse should have flame retardant performance. After the flame retardant performance test specified in 8.5.7 of this standard, the length of the burned and damaged parts of the specified sample should not exceed 60mm.
7.2 Performance requirements
7.2.1 Resistance value of fuse link and its allowable deviation The resistance value of fuse link and its allowable deviation shall be specified in the product drawings or relevant technical documents. 7.2.2 Dielectric properties
7.2.2.1 Clearance
The minimum clearance of fuse link is related to the withstand voltage and pollution level, and its value shall comply with the provisions of case B in table 11 of 7.1.3 of GB/T37831994. If the minimum clearance is less than the minimum clearance specified in case A, the rated impulse withstand voltage test specified in table 5 must be carried out. If the minimum clearance is greater than or equal to the minimum clearance specified in case A, the rated impulse withstand voltage test is not required. 7.2.2.2 Creepage distance
The minimum creepage distance of the fuse is related to the rated insulation voltage, pollution degree and insulation group. Its value shall comply with the provisions of 7.1.3 Table 12 of GB/T3783-1994. The insulation material used for the fuse shall have a tracking index (CTI) of not less than 100. For fuses intended to be installed in places of important use, the CTI value shall not be less than 175.
7.2.2.3 Power frequency withstand voltage
The maximum phase
to-ground voltage (AC effective value or DC) determined by the rated voltage of the power supply system V
Rated impulse withstand voltage
JB/T6329—2002
Priority value of rated impulse withstand voltage (1.2/50us, OmUmg) kV Installation category (overvoltage category)
Power frequency withstand voltage value (Table 6) is used for the dielectric property verification of fuses without specified rated impulse withstand voltage Ui and the verification of the dielectric property of fuses after the damp and heat resistance test in 8.5.2 of this standard. Table 6
Rated voltage U of fuse holder,
U,≤60
601 Replacement of fuse-links
It shall be possible to replace fuse-links easily and safely. 7.1.2 Connections including terminals
Fixed connections shall be able to maintain the necessary contact pressure under conditions of use and operation. The terminals shall not rotate or shift when the connection screws are tightened, and the connected conductors shall not move. The parts clamping the conductors shall be metal and their shape shall not damage the conductors. The structure of the terminals shall ensure good electrical contact and a certain current-carrying capacity. The conductive metal parts shall have sufficient mechanical strength.
7.1.3 Fuse contacts
The contacts of the fuse shall have the necessary contact pressure under conditions of use and operation, especially under the conditions specified in 7.2.5 of this standard. During the disconnection process, the electric force shall not be sufficient to damage the electrical connection between the fuse base and the fuse carrier, between the fuse carrier and the fuse, and between the fuse and the fuse base or other supporting parts. The structure and material of the fuse contacts should ensure that they can maintain good contact under normal use and installation conditions, after repeated loading and unloading, and under long-term non-loading and unloading conditions.
The copper alloy fuse contacts should not crack. 7.1.4 Materials
The insulating parts of the fuse should be made of durable, flame-retardant, moisture-resistant and demand-resistant materials, and toxic materials or materials that can release toxic gases should be avoided as much as possible. In addition to having good corrosion resistance, metal parts should have reliable protection. The suitability of the selected materials can be verified by the following tests, which can be carried out on the fuse or its parts. 7.1.4.1 Aging resistance of elastic parts
The elastic parts of the fuse made of rubber, polyvinyl chloride (PVC) or similar materials (such as gaskets, sealing rings, films and screw cap gaskets) should have aging resistance. The test method for verifying aging resistance is specified in 8.5.1 of this standard. 7.1.4.2 Moisture and heat resistance test
The fuse shall have moisture and heat resistance performance, that is, after the product has been subjected to 55℃, 2 cycles of alternating moisture and heat test, the insulation resistance shall not be lower than the requirements of Table 2. Table 2 Insulation resistance value
Rated insulation
Voltage V
U≤60
Insulation resistance table
Voltage level V
Measured with a 1000V insulation resistance meter
Note: When the rated insulation voltage is greater than 660V, before moisture and heat test
Insulation resistance MQ
After moisture and heat test
JB/T63292002
7.1.4.3 Heat resistance
The fuse shall have no harmful damage at the highest temperature that may be reached under normal working conditions. The verification of heat resistance shall be carried out in accordance with test method 8.5.3.
7.1.4.4 Resistance to mildew
The fuse shall have resistance to mildew. After mildew growth test, the area of the insulating parts exposed to the air shall not exceed the second grade of mildew specified in GB/T2423.16-1999 or the index agreed by the factory, user and ship inspection department. 7.1.4.5 Resistance to salt spray
The fuse shall have resistance to salt spray. After salt spray test, the appearance change of the metal electroplated parts exposed to the air shall meet the requirements of Table 3. The salt spray test cycle shall be in accordance with Table 4. If the fuse is actually used with a shell, the test cycle shall be 96h when the salt spray test is carried out with the shell.
Table 3 Appearance requirements for metal electroplating parts
Coating category
Copper + dart + chromium
Low saw bronze + chromium
Nickel + chromium
Nickel or high tin bronze
Silver, gold
Salt spray test cycle
7.1.4.6 Resistance to abnormal heat and fire hazards Base metal
Copper and copper alloys
Copper and steel alloys
Copper and copper alloys
Table 4 Salt spray test cycle
Qualification requirements
No brown rust on the main surface
No light green corrosion on the main surface
No light green corrosion on the main surface
No gray or light green corrosion on the main surfaceNo gray black corrosion on the main surface
No steel green on the main surface
Suitable occasions
Fuse installed in the ship's machinery room or other general compartmentsFuse installed on the open deck
Insulating material parts may be subjected to thermal stress due to electrical effects, and insulation deterioration may damage electrical safety. The insulating parts of the fuse should be subjected to the assessment of the burning test.
7.1.4.7 Flame retardant performance
The insulating material of the fuse should have flame retardant performance. After the flame retardant performance test specified in 8.5.7 of this standard, the length of the burned and damaged parts of the specified sample should not exceed 60mm.
7.2 Performance requirements
7.2.1 Resistance value of fuse link and its allowable deviation The resistance value of fuse link and its allowable deviation shall be specified in the product drawings or relevant technical documents. 7.2.2 Dielectric properties
7.2.2.1 Clearance
The minimum clearance of fuse link is related to the withstand voltage and pollution level, and its value shall comply with the provisions of case B in table 11 of 7.1.3 of GB/T37831994. If the minimum clearance is less than the minimum clearance specified in case A, the rated impulse withstand voltage test specified in table 5 must be carried out. If the minimum clearance is greater than or equal to the minimum clearance specified in case A, the rated impulse withstand voltage test is not required. 7.2.2.2 Creepage distance
The minimum creepage distance of the fuse is related to the rated insulation voltage, pollution degree and insulation group. Its value shall comply with the provisions of 7.1.3 Table 12 of GB/T3783-1994. The insulation material used for the fuse shall have a tracking index (CTI) of not less than 100. For fuses intended to be installed in places of important use, the CTI value shall not be less than 175.
7.2.2.3 Power frequency withstand voltage
The maximum phase
to-ground voltage (AC effective value or DC) determined by the rated voltage of the power supply system V
Rated impulse withstand voltage
JB/T6329—2002
Priority value of rated impulse withstand voltage (1.2/50us, OmUmg) kV Installation category (overvoltage category)
Power frequency withstand voltage value (Table 6) is used for the dielectric property verification of fuses without specified rated impulse withstand voltage Ui and the verification of the dielectric property of fuses after the damp and heat resistance test in 8.5.2 of this standard. Table 6
Rated voltage U of fuse holder,
U,≤60
601 Replacement of fuse-links
It shall be possible to replace fuse-links easily and safely. 7.1.2 Connections including terminals
Fixed connections shall be able to maintain the necessary contact pressure under conditions of use and operation. The terminals shall not rotate or shift when the connection screws are tightened, and the connected conductors shall not move. The parts clamping the conductors shall be metal and their shape shall not damage the conductors. The structure of the terminals shall ensure good electrical contact and a certain current-carrying capacity. The conductive metal parts shall have sufficient mechanical strength.
7.1.3 Fuse contacts
The contacts of the fuse shall have the necessary contact pressure under conditions of use and operation, especially under the conditions specified in 7.2.5 of this standard. During the disconnection process, the electric force shall not be sufficient to damage the electrical connection between the fuse base and the fuse carrier, between the fuse carrier and the fuse, and between the fuse and the fuse base or other supporting parts. The structure and material of the fuse contacts should ensure that they can maintain good contact under normal use and installation conditions, after repeated loading and unloading, and under long-term non-loading and unloading conditions.
The copper alloy fuse contacts should not crack. 7.1.4 Materials
The insulating parts of the fuse should be made of durable, flame-retardant, moisture-resistant and demand-resistant materials, and toxic materials or materials that can release toxic gases should be avoided as much as possible. In addition to having good corrosion resistance, metal parts should have reliable protection. The suitability of the selected materials can be verified by the following tests, which can be carried out on the fuse or its parts. 7.1.4.1 Aging resistance of elastic parts
The elastic parts of the fuse made of rubber, polyvinyl chloride (PVC) or similar materials (such as gaskets, sealing rings, films and screw cap gaskets) should have aging resistance. The test method for verifying aging resistance is specified in 8.5.1 of this standard. 7.1.4.2 Moisture and heat resistance test
The fuse shall have moisture and heat resistance performance, that is, after the product has been subjected to 55℃, 2 cycles of alternating moisture and heat test, the insulation resistance shall not be lower than the requirements of Table 2. Table 2 Insulation resistance value
Rated insulation
Voltage V
U≤60
Insulation resistance table
Voltage level V
Measured with a 1000V insulation resistance meter
Note: When the rated insulation voltage is greater than 660V, before moisture and heat test
Insulation resistance MQ
After moisture and heat test
JB/T63292002
7.1.4.3 Heat resistance
The fuse shall have no harmful damage at the highest temperature that may be reached under normal working conditions. The verification of heat resistance shall be carried out in accordance with test method 8.5.3.
7.1.4.4 Resistance to mildew
The fuse shall have resistance to mildew. After mildew growth test, the area of the insulating parts exposed to the air shall not exceed the second grade of mildew specified in GB/T2423.16-1999 or the index agreed by the factory, user and ship inspection department. 7.1.4.5 Resistance to salt spray
The fuse shall have resistance to salt spray. After salt spray test, the appearance change of the metal electroplated parts exposed to the air shall meet the requirements of Table 3. The salt spray test cycle shall be in accordance with Table 4. If the fuse is actually used with a shell, the test cycle shall be 96h when the salt spray test is carried out with the shell.
Table 3 Appearance requirements for metal electroplating parts
Coating category
Copper + dart + chromium
Low saw bronze + chromium
Nickel + chromium
Nickel or high tin bronze
Silver, gold
Salt spray test cycle
7.1.4.6 Resistance to abnormal heat and fire hazards Base metal
Copper and copper alloys
Copper and steel alloys
Copper and copper alloys
Table 4 Salt spray test cycle
Qualification requirements
No brown rust on the main surface
No light green corrosion on the main surface
No light green corrosion on the main surface
No gray or light green corrosion on the main surfaceNo gray black corrosion on the main surface
No steel green on the main surface
Suitable occasions
Fuse installed in the ship's machinery room or other general compartmentsFuse installed on the open deck
Insulating material parts may be subjected to thermal stress due to electrical effects, and insulation deterioration may damage electrical safety. The insulating parts of the fuse should be subjected to the assessment of the burning test.
7.1.4.7 Flame retardant performance
The insulating material of the fuse should have flame retardant performance. After the flame retardant performance test specified in 8.5.7 of this standard, the length of the burned and damaged parts of the specified sample should not exceed 60mm.
7.2 Performance requirements
7.2.1 Resistance value of fuse link and its allowable deviation The resistance value of fuse link and its allowable deviation shall be specified in the product drawings or relevant technical documents. 7.2.2 Dielectric properties
7.2.2.1 Clearance
The minimum clearance of fuse link is related to the withstand voltage and pollution level, and its value shall comply with the provisions of case B in table 11 of 7.1.3 of GB/T37831994. If the minimum clearance is less than the minimum clearance specified in case A, the rated impulse withstand voltage test specified in table 5 must be carried out. If the minimum clearance is greater than or equal to the minimum clearance specified in case A, the rated impulse withstand voltage test is not required. 7.2.2.2 Creepage distance
The minimum creepage distance of the fuse is related to the rated insulation voltage, pollution degree and insulation group. Its value shall comply with the provisions of 7.1.3 Table 12 of GB/T3783-1994. The insulation material used for the fuse shall have a tracking index (CTI) of not less than 100. For fuses intended to be installed in places of important use, the CTI value shall not be less than 175.
7.2.2.3 Power frequency withstand voltage
The maximum phase
to-ground voltage (AC effective value or DC) determined by the rated voltage of the power supply system V
Rated impulse withstand voltage
JB/T6329—2002
Priority value of rated impulse withstand voltage (1.2/50us, OmUmg) kV Installation category (overvoltage category)
Power frequency withstand voltage value (Table 6) is used for the dielectric property verification of fuses without specified rated impulse withstand voltage Ui and the verification of the dielectric property of fuses after the moisture and heat resistance test in 8.5.2 of this standard. Table 6
Rated voltage U of fuse holder,
U,≤60
603 Heat resistance
The fuse shall have no harmful damage under the highest temperature that may be reached under normal working conditions. The verification of heat resistance shall be carried out according to test method 8.5.3.
7.1.4.4 Heat resistance
The fuse shall have heat resistance. After the mildew test, the area of the insulating parts exposed to the air shall generally not exceed the second level of mildew specified in GB/T2423.16-1999 or the indicators agreed by the factory, user and ship inspection department. 7.1.4.5 Salt spray resistance
The fuse shall have salt spray resistance. After the salt spray test, the appearance change of the metal electroplated parts exposed to the air shall comply with the provisions of Table 3. The salt spray test cycle shall comply with the provisions of Table 4. If the fuse is actually used with a shell, the test cycle shall be 96h when the salt spray test is carried out with the shell.
Table 3 Appearance requirements for metal electroplating parts
Coating category
Copper + dart + chromium
Low saw bronze + chromium
Nickel + chromium
Nickel or high tin bronze
Silver, gold
Salt spray test cycle
7.1.4.6 Resistance to abnormal heat and fire hazards Base metal
Copper and copper alloys
Copper and steel alloys
Copper and copper alloys
Table 4 Salt spray test cycle
Qualification requirements
No brown rust on the main surface
No light green corrosion on the main surface
No light green corrosion on the main surface
No gray or light green corrosion on the main surfaceNo gray black corrosion on the main surface
No steel green on the main surface
Suitable occasions
Fuse installed in the ship's machinery room or other general compartmentsFuse installed on the open deck
Insulating material parts may be subjected to thermal stress due to electrical effects, and insulation deterioration may damage electrical safety. The insulating parts of the fuse should be subjected to the assessment of the burning test.
7.1.4.7 Flame retardant performance
The insulating material of the fuse should have flame retardant performance. After the flame retardant performance test specified in 8.5.7 of this standard, the length of the burned and damaged parts of the specified sample should not exceed 60mm.
7.2 Performance requirements
7.2.1 Resistance value of fuse link and its allowable deviation The resistance value of fuse link and its allowable deviation shall be specified in the product drawings or relevant technical documents. 7.2.2 Dielectric properties
7.2.2.1 Clearance
The minimum clearance of fuse link is related to the withstand voltage and pollution level, and its value shall comply with the provisions of 7.1.3 Table 11 Case B in GB/T37831994. If the minimum clearance is less than the minimum clearance specified in Case A, the rated impulse withstand voltage test specified in Table 5 must be carried out. If the minimum clearance is greater than or equal to the minimum clearance specified in Case A, the rated impulse withstand voltage test is not required. 7.2.2.2 Creepage distance
The minimum creepage distance of the fuse is related to the rated insulation voltage, pollution degree and insulation group. Its value shall comply with the provisions of 7.1.3 Table 12 of GB/T3783-1994. The insulation material used for the fuse shall have a tracking index (CTI) of not less than 100. For fuses intended to be installed in places of important use, the CTI value shall not be less than 175.
7.2.2.3 Power frequency withstand voltage
The maximum phase
to-ground voltage (AC effective value or DC) determined by the rated voltage of the power supply system V
Rated impulse withstand voltage
JB/T6329—2002
Priority value of rated impulse withstand voltage (1.2/50us, OmUmg) kV Installation category (overvoltage category)
Power frequency withstand voltage value (Table 6) is used for the dielectric property verification of fuses without specified rated impulse withstand voltage Ui and the verification of the dielectric property of fuses after the moisture and heat resistance test in 8.5.2 of this standard. Table 6
Rated voltage U of fuse holder,
U,≤60
603 Heat resistance
The fuse shall have no harmful damage under the highest temperature that may be reached under normal working conditions. The verification of heat resistance shall be carried out according to test method 8.5.3.
7.1.4.4 Heat resistance
The fuse shall have heat resistance. After the mildew test, the area of the insulating parts exposed to the air shall generally not exceed the second level of mildew specified in GB/T2423.16-1999 or the indicators agreed by the factory, user and ship inspection department. 7.1.4.5 Salt spray resistance
The fuse shall have salt spray resistance. After the salt spray test, the appearance change of the metal electroplated parts exposed to the air shall comply with the provisions of Table 3. The salt spray test cycle shall comply with the provisions of Table 4. If the fuse is actually used with a shell, the test cycle shall be 96h when the salt spray test is carried out with the shell.
Table 3 Appearance requirements for metal electroplating parts
Coating category
Copper + dart + chromium
Low saw bronze + chromium
Nickel + chromium
Nickel or high tin bronze
Silver, gold
Salt spray test cycle
7.1.4.6 Resistance to abnormal heat and fire hazards Base metal
Copper and copper alloys
Copper and steel alloys
Copper and copper alloys
Table 4 Salt spray test cycle
Qualification requirements
No brown rust on the main surface
No light green corrosion on the main surface
No light green corrosion on the main surface
No gray or light green corrosion on the main surfaceNo gray black corrosion on the main surface
No steel green on the main surface
Suitable occasions
Fuse installed in the ship's machinery room or other general compartmentsFuse installed on the open deck
Insulating material parts may be subjected to thermal stress due to electrical effects, and insulation deterioration may damage electrical safety. The insulating parts of the fuse should be subjected to the assessment of the burning test.
7.1.4.7 Flame retardant performance
The insulating material of the fuse should have flame retardant performance. After the flame retardant performance test specified in 8.5.7 of this standard, the length of the burned and damaged parts of the specified sample should not exceed 60mm.
7.2 Performance requirements
7.2.1 Resistance value of fuse link and its allowable deviation The resistance value of fuse link and its allowable deviation shall be specified in the product drawings or relevant technical documents. 7.2.2 Dielectric properties
7.2.2.1 Clearance
The minimum clearance of fuse link is related to the withstand voltage and pollution level, and its value shall comply with the provisions of 7.1.3 Table 11 Case B in GB/T37831994. If the minimum clearance is less than the minimum clearance specified in Case A, the rated impulse withstand voltage test specified in Table 5 must be carried out. If the minimum clearance is greater than or equal to the minimum clearance specified in Case A, the rated impulse withstand voltage test is not required. 7.2.2.2 Creepage distance
The minimum creepage distance of the fuse is related to the rated insulation voltage, pollution degree and insulation group. Its value shall comply with the provisions of 7.1.3 Table 12 of GB/T3783-1994. The insulation material used for the fuse shall have a tracking index (CTI) of not less than 100. For fuses intended to be installed in places of important use, the CTI value shall not be less than 175.
7.2.2.3 Power frequency withstand voltage
The maximum phase
to-ground voltage (AC effective value or DC) determined by the rated voltage of the power supply system V
Rated impulse withstand voltage
JB/T6329—2002
Priority value of rated impulse withstand voltage (1.2/50us, OmUmg) kV Installation category (overvoltage category)
Power frequency withstand voltage value (Table 6) is used for the dielectric property verification of fuses without specified rated impulse withstand voltage Ui and the verification of the dielectric property of fuses after the moisture and heat resistance test in 8.5.2 of this standard. Table 6
Rated voltage U of fuse holder,
U,≤60
60
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