Switch Boards - Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B Service Manual

E-4
THREE
PHASE
INPUT
POWER
INPUT
LINE
SWITCH
PROTECTION
BOARD

SWITCH BOARDS

There are four Switch Boards in the Power Wave, each
containing an input capacitor.
Switch Boards #1 and #2 are always in parallel, and
the capacitors on Switch Boards #3 and #4 are always
in parallel. When the filter capacitors are fully charged,
they act as power supplies for the Switch Boards. The
Switch Boards contain the Field Effect Transistors
(FETs) which, when switched on, supply the Main
Transformer primary windings with DC current flow.
See FET operation discussion and diagrams (Figures
E.10 and E11).
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
THEORY OF OPERATION
FIGURE E.4 – SWITCH BOARD CIRCUIT
INPUT
RECTIFIER
INPUT AND
CONTACTOR RECONNECT
LEFT
SWITCH
BOARD
FET
ASSEMBLY
AUX.
TRANS
RIGHT
SWITCH
BOARD
FAN
FET
ASSEMBLY
POWER
BOARD
WATER
COOLER
PC
INTERFACE
The capacitors on
POWER WAVE 450
MAIN OUTPUT
TRAMSFORMER
RECTIFIER
CT
SNUBBER
SENSE LEADS
CONTROL
BOARD
LCD
DISPLAY
DISPLAY
BOARD
KEYPAD
OVERLAY
WF1 WF2
E-4
CHOKE POSITIVE
NEGATIVE
SHUNT
AND