The Arrestek exothermic welding process is a simple, self-contained method of forming high quality electrical connections. The compact process requires no external power pr heat source making it completely portable. Connections are made inside a semi-permanent graphite mould using the high temperature reaction of powdered copper oxide and aluminum.
This is how it works:
The Mould (1) features a Crucible (2), a Tap Hole (3) and a Weld Cavity (4).
The conductors (5) and (6) to be joined are located in the weld cavity as shown, and the mould is closed. A steel Retaining Disc (7) is located in the bottom of the crucible to retain the Weld Powder (8) and Ignition Powder (9) which are poured in on top.
Ignited with a spark gun, the starting powder sets off an exothermic reaction in the weld powder, reducing it to molten copper alloy. Tis instantaneously melts the retaining disc, and flows down the tap hole, to the weld cavity, where it partially melts the conductors, before cooling to leave a fusion weld of great mechanical strength and electrical integrity.
The majority of Arrestek weld connections have at least twice the cross sectional area of the conductors being joined, and an equivalent or greater current carrying capacity.
Because the connection is a fusion of high conductivity, high copper content alloy, it will withstand repeated fault currents, and will not loosen in the way that mechanical connectors can. Corrosion resistance, too, is exceptional, due to the alloy’s very high copper content (in excess of 90%).