ULTRAFEED VAF-4
Manual 0-5332
TROUBLESHOOTING 5-19
5.12 Main Circuit Description
!
WARNING
Turn off power and disconnect interconnection plug from receptacle before working on the unit. Allow
30 seconds for capacitors to discharge after disconnection.
Motor Control PCB
Display PCB
Art # A-12024_AB
+15V
GND
CANH
CANL
SHIELD
+5.0V
TACHO
GND
+24V
SOLENOID
TRIGGER A
TRIGGER B
A
B
Figure 5-9
All incoming signals between the power source and wirefeeder are carried on the 19 pin interconnection control
cable.
The incoming supply voltage to power the wirefeeder can be either 42VAC or 110VAC. The VAF-4 wirefeeder will
use whichever is available. If both are available, the VAF-4 wirefeeder will use the 110VAC supply voltage.
19 pin E has the 110VAC “hot” supply, 19 pin S has the 42VAC “hot” supply, 19 pin F has the common for both the
42VAC and 110VAC supplies. The 110VAC and 42VAC supplies should be in phase.
The incoming supply voltage to power the wirefeeder is connected via a double pole switch and circuit to the input
rectifiers.
The 110VAC supply uses one pole of the double pole switch, the 4A circuit breaker, and connects through to recti-
fier BR1. The 42VAC supply uses the other pole of the double pole switch, the 8A circuit breaker, and connects
through to rectifier BR2. The outputs of BR1 & BR2 are connected in parallel and then connected to the Motor Con-
trol PCB1. The rectifier positive output is connected to P9 on the Motor Control PCB1. The rectifier negative output
is connected to P10 on the Motor Control PCB1.
It is possible under certain circumstances, that welding current can flow through the earth wire in the control cable
of the interconnection lead. This earth wire is rated in excess of 10A, but if welding current flows, this wire can
“burn out”. The VAF-4 wirefeeder incorporates a detection circuit to detect this and shut down power source and
wirefeeder if this fault happens. The earth wire to the wire feeder’s control box, is connected as a coil around a
reed switch on the Motor Control PCB1. Any current of greater than approximately 5A will trip the reed switch, the
wirefeeder will stop feeding wire and the fault LED on the front panel will illuminate. The error code corresponding
to the fault will be shown on the display.
