Valley FABRICATOR 251 Service Manual - Fabricator 251
7-4
August 22, 2008
FABRICATOR 251
SERVICE MANUAL
J. Set MODE SELECTOR SWITCH to STITCH position.
Set WELD (SPOT/STITCH) TIMER CONTROL to
minimum.
1. Depress Gun Switch
a. Gas Flows
b. Contactor energizes
c. Feed Roll begins a cycle of turning for .5
seconds then stop turning for .5 seconds
d. Display reads "15.0 V"
2. Released Gun Switch
a. Gas flow stops
b. Contactor de-energizes
c. Feed Roll stops
d. Display reads "0.0 V"
K. Set WELD (SPOT/STITCH) TIMER CONTROL to
Maximum position "4" . Set DWELL (STITCH) TIMER
CONTROL to Maximum Position "4"
1. Depress Gun Switch
a. Gas flows
b. Contactor energizes
c. Feed roll begins a cycle of turning for 12
seconds then stop turning for 12 seconds
d. Display reads "15.0 V"
2. Release Gun Switch
a. Gas flow stops
b. Contactor de-energizes
c. Feed Roll Stops
d. Display reads "0.0 V"
L. Connect voltmeter probes to JB-6 (-) and J6-8 (+).
Depress the gun trigger and vary the WIRE SPEED
CONTROL potentiometer from minimum to maximum.
The voltage should vary from approx 4VDC up to
approx 27 VDC.
M. Set COARSE VOLTAGE SELECTOR SWITCH to
position "H". Set FINE VOLTAGE SELECTOR SWITCH
to position "8".
N. Connect voltmeter probes to JB-6 (-) and J6-8 (+).
Depress the gun trigger and vary the WIRE SPEED
CONTROL potentiometer from minimum to maximum.
The voltage should vary from approx 2VDC up to
approx 25 VAC.
O. Set WIRE SPEED CONTROL to "4"
P. Set COARSE VOLTAGE SELECTOR SWITCH to
position "L".
Q. Set FINE VOLTAGE SELECTOR SWITCH to position "1".
This completes the Logic & Control Tests. If the above
are all correct then proceed to paragraph 'C'. If the above
does not function as noted then note the symptom and
proceed to Section 7.09 Logic & Control Problems.
7.05 Spool Gun Control (J1) Test
A. Set MIG GUN / SPOOL GUN SELECTOR SWITCH to
SPOOL GUN position.
B. Connect inlet gas supply hose to spool gun gas inlet
Jumper J1 terminals D & G
1. Gas Flows from Spool Gun gas outlet port on the
front panel
2. Contactor W1 Closes
3. Feed Roll does not turn
C. Check voltages at the following points:
J11 PINS
From Pin H to JB-5 on MAIN PCB
1VDC
From Pin E to JB-5
4.5VDC
From Pin C to Pin B
14VDC*
(*Because there is no load from a motor this
voltage will slowly drop)