BF2 Fuse

BF2 fuse – MEGA-class bolt-down fuse by Littelfuse for high vehicle electrical currents

The BF2 fuse by Littelfuse is a bolt-down fuse of the MEGA class and thus a stand-alone, considerably larger design within the BF series. Compared with the compact BF1 (MIDI class), the BF2 covers a clearly higher current range and addresses protection tasks with stronger loads and a vibration-resistant bolt connection. At SULEJ Ladebordwand you will find the BF2 fuse as a reliable protection module for high-power electrical branches in trucks and vans.

Bolt-down housing of the BF2 and mechanical layout

The BF2 fuse is characterised by a block-shaped PPA thermoplastic housing with two bolt eyelets whose hole pattern and current capability are tailored to the MEGA class and therefore clearly differ from the smaller BF1 – the distinction lies not only in the hole spacing but above all in size and current range. The series is rated for 58 V electrical system voltage (also available in 32 V) and covers a typical current range of approximately 100 to 300 A, with the 300 A variant intended for short-circuit protection only. Tripping is Slo-Blo® time-delayed. The breaking capacity is 2000 A and the permitted operating temperature ranges from -40 °C to +125 °C. A transparent cover supports optical condition checks.

What to consider when selecting and replacing the BF2

For BF2 fuse selection, nominal current (typically 100–300 A), electrical system voltage (32 V or 58 V) and the specific bolt centre distance at the existing fuse holder are decisive. It is the right choice when the vehicle manufacturer specifies the MEGA class with BF2 geometry as the protective element for a higher-power main distribution branch. During replacement, visual inspection of contact surfaces for oxidation or discolouration is recommended, along with clean bolt tightening at the defined torque to keep contact resistance low.

Benefits at a glance

• MEGA class: typical current range approx. 100–300 A, clearly higher than the BF1 (MIDI class)
• PPA thermoplastic housing with bolt eyelets for a vibration-resistant bolt-down seat
• Slo-Blo® time-delayed tripping, electrical system voltages 32 V / 58 V
• Breaking capacity 2000 A, operating temperature -40 °C to +125 °C
• Transparent cover for fast condition and current rating identification

A correctly selected BF2 fuse protects the relevant high-current branch in its intended configuration and preserves the protection logic originally defined by the vehicle manufacturer.