Optional Start And Crater Fill Boards - Lincoln Electric NA-3 Service Manual

E-5
OPTIONAL START AND
CRATER FILL BOARDS
When installed, the optional start board as
shown in Figure E.4 dictates to the logic
board the starting weld current and arc
voltage. This condition can be operator set
for a predetermined period of time. These
parameters can be set either higher or lower
than those of the welding procedure to
control penetration, bead shape, or other
factors at the start of the weld. The start
circuit becomes active when the weld current
sensing reed switch (4CR) is closed.
FIGURE E.4 – OPTIONAL START AND CRATER FILL BOARDS.
CIRCUIT
BREAKER
115 VAC
115 VAC
FROM
WELDING
POWER
SOURCE
115 VAC
THEORY OF OPERATION
TRAVEL
RECEPTACLE
TRAVEL
SWITCH
115 VAC
2CR TRAVEL
RELAY CONTACTS
INCH UP
SWITCH
R1
CONTROL
115 VAC
VARIABLE
VOLTAGE
115 VAC BOARD
ELECTRODE
VOLTAGE
SENSING
LEADS
WORK
115 VAC
NA-3 AND NA-4
The crater fill board, as shown in Figure E.4,
is used by the operator to adjust the finishing
and voltage either higher or lower than that
of the welding procedure for an adjustable
period of time. This circuit becomes active
when the "Stop" switch is pressed. The
crater fill board then dictates to the logic
board the appropriate signals. This feature
is helpful in controlling bead shape and filling
craters at the end of a weld.
115 VAC
WELD CURRENT SENSING
WIRE
DRIVE
MOTOR
LOGIC CONTROL
BOARD
SIGNALS
24 VDC
ARC VOLTAGE
SENSING SIGNALS
START
SWITCH
STOP
SWITCH
INCH
DOWN
SWITCH
WIRE FEED
ARC
SPEED CONTROL
VOLTAGE
METER
REED SWITCH 4CR
OPTIONAL
START
BOARD
OPTIONAL
CRATER
FILL
BOARD
LOGIC
BOARD
1 CR
2 CR
3 CR
POWER SOURCE
OUTPUT CONTROL
115 VAC
E-5