Valley FABRICATOR 251, Руководство по обслуживанию

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August 22, 2008 7-7
SERVICE MANUAL FABRICATOR 251
7.09 Logic and Control Problems
A. Nothing happens when gun switch is depressed;
No gas flow, contactor does not energize, feed
rolls do not turn. TEMPERATURE LED is on.
1. Unit ove r heated.
a. Allow unit to cool
2. Insufficient ai r flow a r ound / th r ough unit.
a. See installation section 3.02 fo r clea r ance
r equi r ements
3. Open The r mal P r otection Switch TS1 o r TS2
a. Check continuity on the MAIN PCB JA
connecto r between pins 5 & 7 and if open check
the switches TS1 & TS2 individually and r eplace
the defective switch.
B. Nothing happens when gun switch is depressed;
No gas flow, contactor does not energize, feed
rolls do not turn. TEMPERATURE led is off.
1. MIG GUN / SPOOL GUN SELECTOR SWITCH SW2
is in SPOOL GUN position
a. Set SW2 to MIG GUN position
2. Defective SW2
a. Check continuity of SW2.
3. Defective gun switch
a. Check continuity of gun switch
4. Open wi r es between gun r eceptacle and MAIN PCB
(PCB 1)
a. Measu r e between JA-1 to JA-2 at the Cont r ol
PCB fo r app r ox 40 VDC when switch is open
and then d r ops to 0 VDC when gun switch is
closed. If it does not d r op check continuity of
the wi r es.
5) Faulty Fan/Aux. t r ansfo r me r assembly M1
a. With Gun Switch dep r essed, measu r e fo r app r ox
30 VAC between the b r own (#30) and o r ange
(#31C). If low o r not p r esent, r eplace M1.
6. Faulty MAIN PCB (PCB 1)
a. Measu r e at PCB 1 between JB-5 to JA-1 fo r
40VDC. If voltage is not p r esent, r eplace PCB-1
7). Faulty MIG TIMER PCB (PCB 2)
a. See Section 7.15
8. Faulty MAIN PCB 1
a. Measu r e between JB-4 to JB-11 at PCB 1 fo r
app r ox 30 VAC when gun switch is closed. If
voltage is not p r esent, r eplace PCB.
9. Faulty SPOOL GUN PCB (PCB 3)
a) Measu r e at PCB1 between JB-5 to JA-2 fo r
21VDC. If voltage is not p r esent, r eplace PCB3
C. When gun switch is closed, gas flows, contactor
does not energize, feed roll does not turn.
1. Defective Contacto r W1
a. Measu r e fo r 30VAC on the contacto r coil
between White wi r e (#31C) and white wi r e
(#32A). If voltage is p r esent r eplace W1.
D. When Gun Switch is closed, no gas flows but
contactor closes and feed rolls turn.
1. Gas supply not connected o r tu r ned on
a. Ve r ify gas supply to unit is co rr ect and
connected to the gas inlet labeled:
2. Defective Gas Solenoid SOL1
a. With gun switch closed, measu r e fo r 30VAC
on the gas solenoid between O r ange wi r es
(#31A & 31B) and Blue wi r e (#33). If voltage
is p r esent r eplace gas solenoid.
3. Defective MIG GUN / SPOOL GUN SELECTOR
SWITCH SW2
a. With gun switch closed, measu r e fo r 30VAC
on the gas solenoid between O r ange wi r es
(#31A o r 31B) and Blue wi r e (#33). If voltage
is not p r esent, check SW2.
E. When Gun Switch is closed, gas flows, contactor
closes, display shows 15 volts, but feed rolls do
not turn
1. CB2 5 amp Ci r cuit B r eake r t r ipped
a. Reset CB2
2. Defective WIRE FEED MOTOR M2
a. With Gun Switch closed, measu r e fo r app r ox
2-16 vdc va r iation at the cont r ol PCB between
JB-6 to JB-8 as the WIRE SPEED CONTROL
potentiomete
r is va r ied f r om minimum to maxi-
mum. If voltage is co rr ect, r eplace moto r .