SINOFUSE RS309-MF-EV Series AC/DC 750V gR Cylindrical Bolt-Connected Fuse

The SINOFUSE RS309-MF-EV Series is a cylindrical bolt-connected fuse family designed for demanding road-vehicle and high-power electrical applications. The series is rated at AC/DC 750V and covers current ratings from 20A to 100A.

According to the SINOFUSE manufacturer specification, the RS309-MF-EV Series uses the gR utilization category under IEC requirements and provides high breaking capacity for applications requiring reliable short-circuit, overload, and backup protection.

RS309-MF-EV Series Technical Specifications

  • Manufacturer: SINOFUSE
  • Series: RS309-MF-EV
  • Product Type: Cylindrical bolt-connected fuse
  • Rated Voltage: AC/DC 750V
  • Rated Current Range: 20A to 100A
  • Utilization Category: gR (IEC)
  • AC Breaking Capacity: 100kA
  • DC Breaking Capacity: 50kA
  • DC Time Constant: ≤15ms
  • Performance Standards: IEC 60269, ISO 8820 and GB/T 31465
  • Certification: CE
  • Environmental Compliance: RoHS

Key Features

  • Compact cylindrical construction
  • High breaking capability
  • Strong resistance to current surges
  • Designed to withstand high mechanical vibration and impact
  • Suitable for wide temperature-range applications
  • Designed for road-vehicle electrical environments
  • Suitable for demanding chemical-load conditions

Typical Applications

The manufacturer specifies the RS309-MF-EV Series for electrical protection in applications including:

  • Electric vehicle drive power systems
  • Power conversion systems
  • Energy storage systems
  • Power systems
  • Variable frequency controllers
  • Charging equipment
  • Electrical conductors
  • Other automotive electrical devices and equipment
  • Short-circuit protection
  • Overload protection
  • Backup protection

RS309-MF-EV Model Range

The RS309-MF-EV family includes standard 3SA versions from 20A to 100A and additional 4SB EVB versions from 70A to 100A.

Model Size Rated Current Pre-Arcing I²t Total I²t Power Loss
RS309-MF-EV20A 3SA 20A 120 A²s 310 A²s 2W
RS309-MF-EV25A 3SA 25A 180 A²s 460 A²s 3W
RS309-MF-EV30A 3SA 30A 210 A²s 550 A²s 5W
RS309-MF-EV35A 3SA 35A 330 A²s 670 A²s 7W
RS309-MF-EV40A 3SA 40A 430 A²s 1020 A²s 8W
RS309-MF-EV45A 3SA 45A 850 A²s 1660 A²s 9W
RS309-MF-EV50A 3SA 50A 1020 A²s 1850 A²s 9.5W
RS309-MF-EV60A 3SA 60A 1200 A²s 2800 A²s 10W
RS309-MF-EV70A 3SA 70A 1680 A²s 3400 A²s 11W
RS309-MF-EV80A 3SA 80A 2100 A²s 6800 A²s 12.5W
RS309-MF-EV90A 3SA 90A 3110 A²s 9900 A²s 13W
RS309-MF-EV100A 3SA 100A 4130 A²s 11800 A²s 14W
RS309-MF-EVB70A 4SB 70A 1680 A²s 3400 A²s 11W
RS309-MF-EVB80A 4SB 80A 2100 A²s 6800 A²s 12.5W
RS309-MF-EVB90A 4SB 90A 3110 A²s 9900 A²s 13W
RS309-MF-EVB100A 4SB 100A 4130 A²s 11800 A²s 14W

Mounting Requirements

The manufacturer specifies an M8 mounting bolt for the RS309-MF-EV Series, with a recommended tightening torque of 12 ±1 N·m.

Reliable electrical contact at the fuse terminals is important. The manufacturer also states that the fuse may be installed vertically, horizontally, or at an inclined angle, provided that stable electrical contact and suitable installation conditions are maintained.

Operating Conditions

  • Normal ambient temperature: -5°C to 40°C
  • Permitted ambient temperature: -40°C to 85°C
  • Product storage temperature: -40°C to 120°C
  • Normal operating altitude: Up to 2000m
  • Permitted altitude: Up to 4500m with application review / derating where required
  • Pollution degree: III

Continuous Current Recommendation

According to the manufacturer specification, the recommended long-term continuous operating current should not exceed 80% of the fuse rated current under the stated normal operating conditions.

Applications above 40°C ambient temperature, at high altitude, or in enclosed environments may require current derating and additional engineering review.

Vibration and Road-Vehicle Suitability

The RS309-MF-EV Series is designed for environments requiring strong resistance to vibration and mechanical impact. The manufacturer references JASO D622-2006, ISO 8820, and GB/T 31465 for vibration and shock performance.

The series is also described as suitable for road-vehicle body installation and for rail-transit Class II application environments.

Browse RS309-MF-EV Models

Apexon Supply provides a multi-specification RS309-MF-EV product page covering the available 20A–100A variants:

View SINOFUSE RS309-MF-EV 20–100A AC/DC750V Fuse Options

Related SINOFUSE Resources

Technical Sourcing Support

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For RS309-MF-EV availability, quotation requests, or technical information, please provide the required current rating, quantity, and any available application details.