1SBN030105T1000

ABB 1SBN030105T1000 – VM4 is a mechanical interlock unit intended for use with compatible ABB AF series contactors, particularly AF09–AF38 configurations. It is installed between two contactors to provide positive mechanical interlocking and prevent both contactors from being energized in the closed position at the same time. This functionality is particularly important in forward/reverse motor starters, reversing contactor combinations, changeover circuits, transfer arrangements and other applications where simultaneous operation of two contactors could create an unsafe or electrically conflicting condition.