IMA 474
DC-400
Page 19
ARC FORCE CONTROL DIAL
(Effective only in CC)
The ARC FORCE control is calibrated from one to ten. For
most welding, the dial should be set at approximately mid-
range, 5-6. Adjustments up or down can then be made
depending on the electrode, procedures, and operator
preference. Lower settings will provide less short circuit
current and a softer arc. A setting that is too low may cause
the electrode to stick in the puddle. Higher settings will
provide a higher short circuit current and a more forceful
arc. Excessive spatter may result if the control setting is too
high. For most TIG welding applications adjust this control
to a minimum for best operating characteristics.
ARC CONTROL SWITCH
(Effective only in CV FCAW/GMAW mode)
The ARC CONTROL is a tapped switch numbered from 1
to 5 and changes the pinch effect of the arc. This control is
most useful in processes that utilise a “shorting” metal
transfer and controls the spatter, fluidity, and bead shape.
The pinch effect is increased by turning the control
clockwise.
For all applications, a good starting point for the ARC
CONTROL is a mid-range dial setting of 3. The control can
be increased or decreased as desired.
OUTPUT TERMINALS SWITCH
The OUTPUT TERMINALS toggle switch on the control
panel labelled “REMOTE - ON” allows the welder output to
be activated remotely or to be always on.
For remote
operation, the toggle switch is set in “REMOTE” position
and the welder output will be activated when 2 and 4 are
closed when using a wire feeder.
For welder output to
always be activated, set the switch to the “ON” position.
110-115V AC and 40-42V AC Auxiliary
Power and Control Connections
14-PIN CONNECTOR
The 14-pin connector receptacle supplies auxiliary power.
40-42V AC is available at receptacle pins I and K. A10 amp
circuit breaker protects this circuit.
110-115V AC is available at receptacle pins A and J. A 10
amp circuit breaker protects this circuit. Note that the 40-
42V AC and 110-115V AC circuits are electrically isolated
from each other.
FRONT VIEW OF 14-PIN
CONNECTOR RECEPTACLE
Terminal Strip Connections
Terminal strip TS2 located behind the hinged control panel
on the front of the power source supplies 110-115V AC. A
10 amp circuit breaker protects this circuit. Note that this
110-115V AC is also available in the 14-pin connector.
To gain access to the terminal strips simply remove the six
#10 sheet metal screws from the perimeter of the welder
nameplate as shown below. Tilt panel forward so it rests in
a horizontal position. See Table showing Front View of 14-
Pin Connector Receptacle for lead number functions.
WELDER NAMEPLATE
Machine and Circuit Protection
The power source is thermostatically protected with
proximity thermostats against overload or insufficient
cooling.
One thermostat is located on the nose of the
centre bottom primary coil and a second thermostat is
attached to the lead connection the secondaries. Both
thermostats are connected in series with 2-4 circuit. If the
machine is overloaded, the primary thermostat will open,
the output will be zero, and the amber thermal protection
light will be on.
The fan will continue to run. The secondary thermostat will
open either with an excessive overload or insufficient
cooling. The output will be zero and the amber protection
light will be off.
F=76
G=75
H=21
N=SPARE
I=41
J=31
K=42
A=32
B=GND
C=2
D=4
E=77
L=SPARE
M=SPARE
Pin
Lead No.
Function
A
32
110 - 115V AC
B
GND
Chassis Connection
C
2
Trigger Circuit
D
4
Trigger Circuit
E
77
Output Control
F
76
Output Control
G
75
Output Control
H
21
Work Connection
I
41
40 - 42V AC
J
31
100 - 115V AC
K
42
40 - 42V AC
L
-
-
M
-
-
N
-
-
3
4
5
6
1
2
ARC WELDING SUPPLIES - 07 847 7870
