Blackburn FB3E12 FLEXIBLE BRAID 504KCMIL, 12 IN LONG

The FB3E12 is a flat, flexible tin-plated copper braid connector used to bond equipment across joints that move or vibrate, such as transformer cases, switchgear doors, generator skids, and expansion points in a grounding path. Because the conductor is braided and flat rather than solid, it absorbs movement without fatiguing the bond. It terminates with two bolt holes at each end, so it lands on drilled bus or a bonding pad rather than crimping onto round cable.

12 inches overall, rated 504 KCMIL. Order by the span you need to bridge plus slack for movement: the braid should never be pulled taut between the two pads, or the flex that protects the bond is lost. It is sold individually.

It carries UL file E3060 and CSA LR29625, so it is recognized under both US and Canadian files. That is the reference an inspector or a spec reviewer will want against a bonding jumper on a grounding electrode system or equipment bonding detail. It is also made in the United States, which matters on Buy American and federally funded work.

It is built as a 2-hole terminal braid, so both ends land on drilled pads or bus with two bolts rather than a single stud. Two-hole landings resist rotation and are what most switchgear and transformer bonding pads are drilled for. Before ordering, check the hole spacing and bolt diameter on your pad against the braid's terminals, since a two-hole pattern is only interchangeable if the centers match.

Tin plating on the FB3E12's copper braid slows oxidation on the strands and at the bolted terminals, which keeps contact resistance stable in damp, outdoor, or corrosive rooms. It also mates more cleanly to aluminum or plated bus than bare copper does. For a dry indoor cabinet either would serve; for a rooftop unit, a pump house, or a water treatment plant, the plated braid holds up longer.

Yes, and that is the point of it. Stranded cable will work electrically but it stiffens and work-hardens where it is clamped, so repeated movement at a busway expansion fitting, a vibration-isolated generator, or a hinged enclosure door eventually cracks strands at the lug. The flat flexible braid takes that motion across many fine strands instead. Where there is no movement, ordinary cable and compression lugs are the simpler install.

The FB3E12 ships as the braid itself, sold each. Hardware to land it, bolts, flat and lock washers, nuts or tapped-pad screws, and any anti-oxidant compound for aluminum bus, is a separate line item. Size that hardware to the holes in your pad, not to the braid alone.

Blackburn FB3E12 is the manufacturer part number for the 12 inch, 504 KCMIL flexible braid. It is a single catalog item sold each, so there is no finish or length option to specify beyond the part number itself.