Constant Voltage Cv Box - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC Classic® 300 MP Service Manual
Figure E.7 – Constant voltage CV box

Constant Voltage CV Box

The CV box contains two contactors and several filter capacitors. When the mode switch is placed into the
CV mode the CV box is activated. One of the contactors is energized and brings the filter capacitors into the
CV welding circuit to provide a more constant DC output voltage for wire welding. The other contactor is in
series with the negative CV output stud. When the control board receives a trigger command signal, from
an external wire feeder, the output contactor is energized and the CV negative output stud now has
continuity to the negative brushes.
9