Blue Sea Systems 5191 MRBF Terminal Fuse Block 30-300A

Price:  £23.52   (£19.60 Exc. VAT)

Product code:  P03972
Brand:  Blue Sea Systems
Ignition Protected  Yes



Awaiting new stock.

Blue Sea Systems MRBF Terminal FusesBlue Sea Systems MRBF Terminal Fuses

This compact, space saving 5191 fuse block from Blue Sea Systems accepts Marine Rated Battery Fuses (MRBF) from 30-300A and is suitable for use on high amperage circuits such as primary battery feed, inverter, windlass, bow thruster, etc.

It provides fusing directly at the battery terminal, meaning that the entire cable length is protected, and is ignition-protected when used with the Blue Sea Systems MRBF fuses. The isolated stud design electrically insulates the stud from the busbar so that all current flows through the fuse. This also allows multiple M8 terminals to be stacked on top of each other (unlike other designs that have a separator/insulator and permit only 1 terminal to be used).

The mounting hole suits M10 studs, allowing the block to be fitted directly to the surface of batteries that have threaded inserts, or to battery terminal clamps that have M10 studs.

Important: Only for use with Blue Sea Systems MRBF fuses. Fuse not included (see below).


  • Compact and space saving
  • Ideal for high amperage circuits
  • Ignition protected when used with MRBF fuses
  • Protects entire length of cable
  • Isolated stud design
  • Insulating cap
  • 58VDC, 300A rating

Further information

A dual fuse version of this block is available here

Fuses are available here

  • Voltage rating (max.): 58V DC
  • Current rating (max.): 300A
  • Terminal Stud: M8 (5/16")
  • Mounting hole: 9.5mm (fits M10 stud)
  • Maximum torque: 75 in-lb (8.47 Nm)
  • Weight: 0.07 kg
  • Overall dimensions: 60.9 (L) x 44.5 (H) x 20.0 (W) mm (exc. insulating cap)
  • Ignition protected: Yes, when used with Blue Sea Systems MRBF fuses
  • Manufacturer's part no: 5191

Part Number:  5191B-BSS

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Blue Sea Systems

Blue Sea Systems is a US-based company designing and manufacturing high-quality components and accessories for the demanding environments of the marine and specialised vehicle markets. Its range consists of over 1000 products, designed to work together as a fully integrated system.

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CALL Sales & Support: 01844 885100
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