Tweco VA 4000 Ultra-Feed - Manual (Page 40)

ULTRAFEED VA 4000
5-2 September 18, 2012
5.05 Troubleshooting Guide
WARNING
ELECTRIC SHOCK can kill.
Follow all safety precautions.
Do not touch live electrical parts.
Turn OFF input power before servicing the
machine unless otherwise noted.
Only qualified technicians are to service the
machine.
WARNINGS
PC boards and their components are static
sensitive devices.
Use static proof bags.
Use grounded wrist strap.
Only qualified personnel should test or handle
these devices.
Use only genuine replacement parts.
A. Unit is completely inoperative - nothing functions
1. Connect the 19 pin power source control cable to
the power source and wire feeder Amphenol
connectors.
2. Turn the power source ON.
3. Place the power switch of the wire feeder to the ON
position.
4. Check the ground fault indicator light.
a. Remove ground fault (refer to Section 4.13
Ground Fault Operation).
5. With the power source turned ON, check for 115
VAC at power source amphenol pins E and F.
a. Refer to the power source owner’s manual.
6. Check continuity of pins E and F of the 19 pin power
source control cable.
a. Replace the 19 pin power source control cable.
7. Check to see why the circuit breaker on the wire
feeder power switch trips.
a. Allow a short cool down period before
attempting to turn the power switch ON again..
8. Check connections on the power switch of the wire
feeder for loose or faulty connections.
a. Repair or replace connection.
B. Wire feed motor operates but wire does not feed
or feeds erratically
1. Check for too little or too much pressure on feed
rolls.
a. Increase or decrease the pressure accordingly
with the spring tension knob (refer to Section
3.09 Threading Wire Into Feedhead).
2. Check for incorrect feed roll sizes.
a. Check size stamped on outside of feed roll.
Match to wire size.
3. Check to see if wire spool tension is too great.
a. Decrease wire spool tension (refer to Section
3.05 Adjustment Of Spool Tension).
4. Check for restriction in welding gun and cable
assembly.
a. Repair or replace gun, cable, liner, or contact
tip.
5. Check for failed insulator on drive gear assembly
— motor shaft turning inside insulator.
a. Replace drive gear assembly.
C. Wire wraps around the feed rolls
1. Check for too much pressure on the welding wire.
a. Decrease the pressure with the spring tension
knob (refer to Section 3.09 Threading Wire Into
Feedhead).
2. Check alignment of input and output wire guides.
a. Re-align wire guides (refer to Section 3.06
Input And Output Wire Guide Installation).
3. Check to see if correct cable liner and contact tip
are being used.