General Maintenance - Lincoln Electric CV450-T Manuel D'utilisation

E1 / E2 / F- Output terminals
Each output terminal is a twist-Mate terminal.
Insert the mating Twist-Mate plug, and twist clockwise
to secure.
For MIG/MAG processes and most FCAW
processes, the positive output connection goes to
the wire feeder and one of the negative output
connections goes directly to the work.
E1- High inductance negative output connection
The high inductance connection is more suitable
when a soft arc is wanted
E2- Low inductance negative output connection
The low inductance connection is typically used
when a crisp arc is wanted.
F- Positive output connection
This connection goes to the brass block of the wire
feeder.
G- Wire feeder receptacle
Provides connection for the wire feeder control
cable.
H- Digital display Selector switch
The selector lever can be positioned either to the V
or A position.
During welding process, arc voltage is displayed
on the V position.
welding current is displayed on A position.
I- Voltmeter/ Ammeter digital display.
As described in the previous paragraph, arc
voltage or welding current are displayed on the
screen according to the lever position (H).

General maintenance

1. The fan motor has sealed bearings which
require no service.
2. In extremely dusty locations, dirt may clog the
air channels causing the machine to run hot
with premature tripping of thermal protection.
Blow out the machine with low pressure air at
regular intervals to eliminate excessive dirt and
dust build-up on internal parts.
Machine and Circuit Protection
The CV450-T is thermostatically protected against
overloads or insufficient cooling. If the machine is
overloaded, the thermostat will open, thermal protection
indicator light will turn on and the output current will be
0. The fan will continue to run and auxiliary power will
still be available. The thermostat will remain open until
the machine cools and the output current will again be
available.
The CV450-T is also electronically protected against
overloads and accidental short-circuits. The overload
protection circuit automatically reduces the output
current to a safe value when an overload is detected. If
the circuitry senses a short circuit, it will shut off the
CV450-T output current. The short-circuit protection
circuit can be reset by turning the CV450-T power
switch. Remove the short before turning the power
switch ON again.
Maintenance
Procedures for replacing PC Boards
Before replacing a PC board which is suspected of
being defective, visually inspect the PC board in
question for any electrical or mechanical damage to any
of its components and conductors.
1) If there is no visible damage to the PC board,
install a new one and see if this remedies the
problem. If the problem is remedied, reinstall the
old PC board to see if the problem still exists. If it
does no longer exist with the old PC board :
2) Check the PC board harness connector pins for
corrosion, contamination or looseness.
3) Check leads in the plug harness for loose or
intermittent connection.
4) If PC board is visibly damaged electrically, before
possibly subjecting the new PC board to the same
cause of failure, check for possible shorts, opens or
grounds caused by :
5) Frayed or pinched lead insulation.
6) Poor lead termination such as poor contact or a
short to adjacent connection or surface.
7) Shorten or open motor leads.
8) Foreign matter or interference behind the PC
boards.
9) If PC board is visibly damaged mechanically,
inspect for cause, then remedy before installing a
replacement one.
PC Board troubleshooting procedures
Control PC boards
The control PC board controls all machine functions
including the thermal protection indicator light. Most
problems, if not caused by faulty wiring or machine
misuse, will come from a faulty control PC board.
Perform the following diagnostic procedure before
replacing the control PC board :
1) Turn off the input power at the fuse box.
2) Check for loose connections in the PC board plugs
(particularly J3).
3) Disconnect the J3 plug from the control PC board.
Measure the resistance between wires 200 and
201 and between wires 202 and 203. Both
resistances should be less than 1 ohm. If they are
not less than 1 ohm, check the wiring back to the
main transformer. If they are less than 1 ohm, refer
to "Procedure for replacing PC boards".
Checking Snubber Circuit
In case of an SCR malfunction or failure, the snubber
assembly should be checked. Disconnect the input
power to the CV450-T at the fuse box and remove the
right side of the machine. Visually inspect the snubber
PC board assembly (located below the control PC
board) for overheated components or damaged
components.
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