SINOFUSE RS308-HB-4G Series 750VDC High-Speed Bolt-Connected Fuse
The SINOFUSE RS308-HB-4G Series is a cylindrical bolt-connected high-speed fuse family designed for short-circuit and backup protection in electric vehicle power systems, energy storage equipment, power conversion systems, and industrial electrical applications.
According to the SINOFUSE manufacturer specification ZR/YC-0041 A2, the series is rated at DC 750V and covers ten current ratings from 10A to 100A. It uses the aR utilization category and provides a DC breaking capacity of 50kA under the manufacturer's specified circuit conditions.
The RS308-HB-4G Series combines compact construction, low power loss, high current-limiting capability, and resistance to mechanical vibration, temperature variation, current surges, and demanding road-vehicle operating environments.
RS308-HB-4G Series Technical Specifications
- Manufacturer: SINOFUSE
- Series: RS308-HB-4G
- Product Type: Cylindrical bolt-connected high-speed fuse
- Rated Voltage: DC 750V
- Rated Current Range: 10A to 100A
- Utilization Category: aR
- DC Breaking Capacity: 50kA
- Specified DC Time Constant: <11ms
- Mechanical Size Code: 4G
- Mounting Bolt: M6
- Recommended Mounting Torque: 5.5 N·m
- Performance Reference: IEC 60269
- Environmental Reliability References: ISO 8820, JASO D622 and GB/T 31465
- Vibration Reference: ISO 16750-3
- Environmental Compliance: RoHS
Technical Note: The manufacturer specification identifies the RS308-HB-4G Series as a DC 750V fuse family. The published voltage rating should not be interpreted as an AC/DC 750V rating.
Key Features
The RS308-HB-4G Series is designed for electrical protection applications requiring compact installation dimensions and rapid interruption of high fault currents.
- DC 750V rated voltage
- Ten rated-current options from 10A to 100A
- aR partial-range high-speed protection
- 50kA DC breaking capacity under specified conditions
- Compact cylindrical construction
- Bolt-connected terminals with M6 mounting hardware
- Low power-loss characteristics
- High current-limiting capability
- Resistance to mechanical vibration and impact
- Suitable for demanding road-vehicle electrical environments
Complete RS308-HB-4G Model Range
The manufacturer specifies ten current ratings across the RS308-HB-4G Series. All listed models use the 4G mechanical size and M6 mounting arrangement.
The following table reproduces the manufacturer-published rated current, pre-arcing I²t, total clearing I²t, and power-loss values.
| Model | Rated Current (A) | Pre-Arcing I²t (A²s) | Total Clearing I²t (A²s) | Power Loss (W) |
|---|---|---|---|---|
| RS308-HB-4G10A | 10 | 7 | 25 | 3.1 |
| RS308-HB-4G16A | 16 | 20 | 70 | 4.6 |
| RS308-HB-4G20A | 20 | 39 | 137 | 5.2 |
| RS308-HB-4G25A | 25 | 51 | 178 | 7.1 |
| RS308-HB-4G32A | 32 | 89 | 307 | 8.9 |
| RS308-HB-4G40A | 40 | 136 | 471 | 11.2 |
| RS308-HB-4G50A | 50 | 320 | 758 | 13.8 |
| RS308-HB-4G63A | 63 | 356 | 1228 | 17.3 |
| RS308-HB-4G80A | 80 | 611 | 2105 | 21.3 |
| RS308-HB-4G100A | 100 | 990 | 3410 | 26 |
Manufacturer Test Conditions: The published I²t values are typical data obtained under DC 750V, 50kA, and 11ms time-constant test conditions. Actual fuse performance must be evaluated according to the applicable electrical system and manufacturer documentation.
Understanding I²t Characteristics
I²t characteristics are important when evaluating high-speed fuse protection for power-electronic and high-current electrical systems.
Pre-Arcing I²t represents the current-squared integral accumulated before the fuse element melts.
Total Clearing I²t represents the current-squared integral accumulated throughout the complete interruption process.
These characteristics help engineers evaluate the energy associated with fault interruption and coordinate fuse protection with the requirements of connected equipment.
For the RS308-HB-4G Series, the manufacturer provides individual I²t values for each current rating. Engineers should review these values together with system voltage, prospective short-circuit current, and applicable time-current characteristics.
DC Breaking Capacity and Protection Category
The RS308-HB-4G Series has a manufacturer-specified DC breaking capacity of 50kA, with a specified circuit time constant below 11ms.
The series uses the aR utilization category, identifying it as a partial-range high-speed fuse family.
Partial-range protection should not automatically be interpreted as complete overload protection over the full range of possible circuit currents.
When designing or evaluating an electrical protection system, engineers should consider the fuse's operating characteristics and coordinate additional protective devices where required.
The exact fuse model should be selected according to the applicable DC voltage, current rating, prospective fault current, time-current characteristics, and protection requirements.
Mechanical Dimensions and Mounting Requirements
All RS308-HB-4G models listed in the manufacturer specification share the 4G mechanical size.
The series uses bolt-connected terminals with M6 mounting hardware.
Mechanical Specifications
- Mechanical Size: 4G
- Mounting Bolt: M6
- Recommended Tightening Torque: 5.5 N·m
- Overall Length Shown in Drawing: 76 ±2mm
- Additional Longitudinal Dimensions: 61 ±3mm and 46 ±1mm
- Nominal Cylindrical Body Diameter: 17.7mm, tolerance +0/-0.5mm
- Terminal Width: 12 ±0.2mm
These values should be interpreted together with the original manufacturer dimensional drawing. For replacement applications, the complete terminal geometry, mounting-hole dimensions, and installation clearances should be verified before ordering.
Installation Considerations
The manufacturer specifies that fuse terminals must maintain stable and reliable electrical contact. Excessive contact resistance may adversely affect fuse operation.
The fuse may be installed vertically, horizontally, or at an inclined angle, provided that the mounting arrangement maintains reliable electrical contact.
The manufacturer also emphasizes the importance of securing the terminal connection to avoid abnormal mechanical stress and additional vibration during installation.
Typical RS308-HB-4G Applications
According to the SINOFUSE manufacturer specification, the RS308-HB-4G Series is intended for electrical protection applications involving electric vehicles and related power-electronic equipment.
Electric Vehicle Drive Power Systems
Electric vehicle power systems require appropriate protection against electrical faults.
The RS308-HB-4G Series is suitable for consideration in DC power circuits where its rated voltage, current range, breaking capacity, and environmental performance meet the equipment requirements.
Power Conversion Systems
Power conversion equipment may require high-speed protection against damaging short-circuit conditions.
RS308-HB-4G fuses can be evaluated for these applications using the manufacturer's time-current and I²t characteristics.
Battery Energy Storage and Power Systems
The manufacturer identifies energy storage and power battery systems among the intended applications for this fuse family.
Selection should consider the DC system voltage, operating current, prospective short-circuit current, circuit time constant, and thermal conditions.
Charging and Industrial Control Equipment
Additional applications identified by the manufacturer include chargers, frequency conversion controllers, energy storage capacitors, electrical conductors, and related vehicle electrical equipment.
For these applications, the exact RS308-HB-4G rating should be verified against the equipment protection requirements.
Operating Temperature and Environmental Conditions
The RS308-HB-4G Series is designed for operation in demanding electrical and mechanical environments.
The manufacturer specifies the following ambient temperature and environmental conditions.
- Normal Ambient Temperature: -5°C to 40°C
- Permitted Ambient Temperature: -40°C to 85°C
- Product Storage Temperature: -40°C to 70°C
- Packaged Storage Temperature: -40°C to 70°C
- Normal Operating Altitude: Up to 2000m
- Permitted Operating Altitude: 2000m to 4500m, subject to correction where required
- Pollution Degree: Class III
For applications above 40°C ambient temperature, the manufacturer specifies that rated-current correction may be necessary.
The applicable correction should be determined using the manufacturer's temperature correction information and the actual installation conditions.
High-Altitude Applications
Higher altitude can affect fuse thermal performance, air pressure, and electrical insulation strength.
For certain enclosed installations where internal temperature does not decrease sufficiently at higher altitude, the manufacturer provides a current-derating guideline of approximately 2% to 5% per 1000m.
The manufacturer also notes that air insulation strength can decrease by approximately 12% to 15% per 1000m between 2000m and 4500m altitude.
Engineers should evaluate the required electrical clearances, thermal conditions, and current correction when installing fuses above the normal operating altitude range.
Vibration and Mechanical Reliability
The manufacturer specifies resistance to mechanical vibration and impact suitable for demanding road-vehicle applications.
The RS308-HB-4G Series references ISO 16750-3 vehicle-body vibration requirements and rail-transport vibration Class II operating environments.
The series is also described as suitable for general motor-vehicle operating conditions.
Applications involving unusually severe vibration or mechanical stress may require additional evaluation or testing.
Safety and Maintenance Considerations
Proper installation and periodic inspection are important for maintaining reliable electrical protection.
- Maintain sufficient electrical clearance between adjacent live components.
- Use insulating barriers where required.
- Ensure reliable electrical contact at mounting terminals.
- Inspect connections for oxidation, dust, and contamination.
- Replace fuses showing mechanical damage.
- Verify the mounting arrangement and terminal contact before returning equipment to service.
Installation, inspection, and replacement should be performed according to the equipment manufacturer's safety procedures and applicable electrical regulations.
RS308-HB-4G Model Selection Checklist
Before selecting an RS308-HB-4G fuse, engineers and procurement professionals should verify:
- Exact manufacturer model number
- Required DC voltage rating
- Rated operating current
- Prospective DC short-circuit current
- Applicable circuit time constant
- Required pre-arcing and total clearing I²t characteristics
- Power loss and thermal conditions
- Mechanical dimensions and mounting-hole configuration
- M6 mounting hardware and tightening torque
- Ambient temperature and installation altitude
- Vibration and environmental requirements
- Applicable certification and equipment requirements
The rated current alone is not sufficient to establish electrical or mechanical suitability. Exact replacement compatibility must be verified using the applicable manufacturer specifications.
Browse SINOFUSE RS308-HB-4G Models
Apexon Supply provides the RS308-HB-4G Series through a dedicated multi-variant product page covering current ratings from 10A to 100A.
For available options, product information, sourcing inquiries, and quotation requests, visit:
View SINOFUSE RS308-HB-4G 750VDC High-Speed Fuse Series – 10A to 100A
Related SINOFUSE Technical Resources
Explore additional SINOFUSE fuse families and related circuit protection resources:
- SINOFUSE Fuse Solutions – Brand & Technical Overview
- SINOFUSE RS309-MF-EV Series 750V gR Cylindrical Bolt-Connected Fuse
- SINOFUSE RS309-MF Series 700V/750V High-Speed Bolt-Mounted Fuse
Series Selection Note: RS308-HB-4G, RS309-MF-EV, and RS309-MF are separate fuse families. Similar voltage or current ratings do not establish electrical or mechanical interchangeability. Replacement suitability should be verified using the applicable manufacturer documentation.
Industrial Sourcing and Technical Support
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For RS308-HB-4G availability, technical information, or quotation requests, please provide the exact part number, rated current, required quantity, and relevant equipment or application information.
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