Electric Welding - ABB ACA 6 Series Hardware Manual

Chapter 2 – Mechanical Installation

Electric Welding

2-10
It is not allowed to fasten cabinets equipped with vibration dampers by
welding because the damper bolts would be welded to the cabinet
frame as well and the dampers would be damaged.
Cabinets without vibration dampers can be welded (although it is not
not recommended) from bottom as follows. Connect the return
conductor of the welding equipment low to the cabinet frame within 0.5
metres of the welding point.
WARNING! If the welding return wire is connected improperly, the
welding circuit may damage electronic circuits located in the cabinets.
ACA 6xx Sections and ACS/ACC 6x7 (132 to 3000 kW) Frequency Converters