Issuing body: DIN
DIN 43673-1
Busbar hole patterns and bolted connections
DIN 43673-1, published February 1982 and running to four pages, specifies drilled holes and screw connections for busbars of rectangular cross-section. It gives the location and size of the holes together with base data for the design of the screw connections, and applies to direct current and to alternating current up to 60 Hz. It is short, it is widely referenced, and it is very often cited on a customer drawing with no dimensions given, on the expectation that the fabricator already works to it. The engineering behind the pattern is edge distance against tear-out, hole pitch against current crowding around the holes, and hole diameter against bolt clearance and contact area.
Technical background
Punching
Punch-to-die clearance for copper and aluminium busbar
How to set punch-to-die clearance per side on 6-20 mm copper and aluminium bar, read the sheared edge, and specify burr height on the drawing.
Standards
Busbar hole patterns and what DIN 43673-1 actually specifies
What the four pages of DIN 43673-1 govern, the engineering behind edge distance, pitch and hole diameter, and why DIN 46433 is not a busbar standard.
Punching
Sizing press force for busbar punching
Work out the punching force a busbar job actually needs, from shear strength and hole perimeter, and match it to a 300-800 kN machine with sane margin.
Materials and finishing
What makes a bolted busbar joint reliable
Constriction resistance, contact pressure targets, plating choice and why torque is a poor proxy for preload in bolted copper busbar joints.
Standards and compliance
Processes