Tweco 2460 Heavy Duty CC CV Control Wire Feeder - Manual (Page 27)

2. Attach the gun and cable to the wire feeder by
following instructions found in the Owner’s Manual
for the Gun and Cable assembly.
WARNING: The welding elec-
trode is electrically “Hot”. Elec-
trode contact to workpiece will
cause an arc with the wire feeder
connected to the workpiece and
gun switch depressed — feed
motor will run feeding “HOT”
electrode.
Operation
Theory of Operation
Refer to Connection Diagram 376784A
With the wire feeder connected to the welding
electrode and the work terminal, turn the power
source and wire feeder on. Power is supplied into
Bridge rectifier CR1. Power on the output side of the
CR1 is fed to the motor control board with the proper
polarity independent of the welding polarity.
When the welding gun switch (S4) is closed, it
energizes the proper components on the PC Board
and causes the motor to run. When the gun switch
is opened, it removes power from the motor and
shorts the armature to provide dynamic braking of
the motor.
When the CC/CV switch (S5) is open, IR compen-
sation is used on the motor control circuit. When S5
is closed, the IR compensation circuit is not active.
Terminal strip TB1 is used to connect various
options to the feeder.
Switch S1 is used to turn the power into the feeder
on or off.
Resistor R1 is the control potentiometer for the unit
which varies the output speed.
The motor control circuit on this feeder is a DC to
DC converter circuit. It uses the power supply output
voltage and changes it to the proper DC voltage
required to operate the motor. The motor is part of
the operating circuit, and the circuit will not operate
properly if the motor is removed.
The circuit is designed for continuous operation
when the input voltage is 30 volts or below. Many
CC power sources have an open circuit voltage of
60 to 100 volts. Under these input conditions, the
circuit will operate and the motor will run. This
condition may exist for a period long enough to feed
wire through the gun when wire spools are changed,
etc., but the motor must never be allowed to operate
with open circuit voltage for prolonged periods of
time.
Options
1. Remote Contactor Control Option — This option
is externally located and connects to the feeder by
means of a control cable which is added to the
feeder. When this option is installed, a relay is
added to the feeder and a 24-V AC gas valve option
is available.
The remote box requires 115-V AC input and in
turn provides 24 V AC to the feeder as well as a
contactor control relay closure to the power source.
The 24 V AC is also used to allow for inching of the
wire feed motor.
2. A voltmeter kit as well as an inches per minute
kit are available for this unit.
3. A remote arc voltage/current control is also
available which allows the user to adjust the power
source at the feeder.
Maintenance
Cleaning of the Unit
Periodically remove a side panel of the cabinet,
and blow out the interior with clean, dry, com-
pressed air of not more than 25 psi (172 kPa)
pressure. Do not strike any of the components with
the air hose nozzle.
TIP-218
CONTROL BOX ASSEMBLY NO. 376783A & 376783B
May 29, 1996 Revised Page 3