Optional Start, Crater Fill And Weld Timer Boards - Lincoln Electric NA-5N Service Manual

E-5
FIGURE E.3 Optional Start, Crater Fill and Weld Timer Boards
CONTACTOR CLOSURE (#2 AND #4)
ARC VOLTS (SET & ACTUAL)
REMOTE VOLTAGE CONTROL (A, B, C)
WORK SENSING (#21)
INPUT
POWER
SWITCH
BREAKER
#31
CONTROL
1 1 5
CABLE
V A C
RECEPTACLE
#32
VOLT
METER
BOARD
DIGITAL
METER
OPTIONAL START, CRATER
FILL AND WELD TIMER
BOARDS
When installed, the optional start board
dictates to the procedure board the
starting wire feed speed and arc volt-
age. 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 weld-
ing 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 is closed.
The crater fill board is used by the oper-
ator to adjust the finishing wire feed
speed and voltage either higher or
lower than the welding procedure for an
adjustable period of time. This circuit
becomes active when the "stop" switch
NOTE: Unshaded areas of block logic diagrams are the subject of discussion.
THEORY OF OPERATION
115VAC
ODE SENSING (#67)
R
T
C
TACH
E
L
E
MOTOR
A
V
R V
F
O
M O
I L
A L
T
T T E
A
U A
L
G
R G
D
E
E E
P
CIRCUIT
F2
O
R1(2 OHMS)
W
E
R
F1
B
O
FIELD
A
R
D
T1 T2
115VAC
1
0 36VAC (18+18VAC)
V
22VAC
A
C
SPEED WIRE FEED SPEED (SET & ACTUAL)
METER
BOARD
DIGITAL
METER
1/2 AMP
F501
VOLTAGE
BOARD
TRAVEL
RECEPTACLE
D
C
S
A 3
U R
CR
A
C
P
N
D
P V
L O
2
S
L
Y H
T CR
U
INCH A
START STOP
T
DOWN G
V
SWITCH D
SWITCH SWITCH E
O
O 1
W
L
CR
N
T
A
G
E
DC SUPPLY VOLTAGE
LOGIC
STRIKE/WELD PROCEDURE
ENABLE
BOARD
DIRECTION SIGNAL F
E
E
D
MOTOR ARMATURE E
WELD
G
N
CURRENT
A
A
REED SWITCH
T
B
E
L
E
S
I
G S
N I
A G
SET SPEED
L N
A
S
L
10VDC REFERENCEVOLTAGE
DC VOLTAGE
CONTROL
BOARD
INCH
UP
SWITCH
is pressed. This optional feature is
helpful in controlling bead shape and
filling craters at the end of a weld.
The weld timer permits setting of weld
time for an adjustable period of time.
This feature eliminates the need to
press the "stop" switch.
NA-5
TACH FEEDBACK (MOTOR RPM)
SET VOLTAGE
FLUX
RECEPTACLE
OPTIONAL
P VOLTS SPEED
START
START
TIMER
BOARD
R
STRIKE
O
B
OPTIONAL
CRATER
C
CRATER
O
TIMER
BOARD
E
A
D
R
OPTIONAL
WELD
U
TIMER
D
R WELD
E
BURNBACK
VOLTS SPEED
TIMER
TACH FEEDBACK (MOTOR RPM)
E-5