Valley FABRICATOR 251 Service Manual - Service Manual
August 22, 2008
8-3
SERVICE MANUAL
FABRICATOR 251
8.04 Circuit Operation Of The Spool Gun
PCB 7978034
CONNECTOR X1
Terminal
X1/1
motor relay "normally open" - connects to spool
gun motor
measure 0 to 24VDC (depends on wire speed
setting)
wrt 7977964 JB/8 in spool gun setting
Terminal
X1/2
motor relay "common" - connects to motor
output from 7977964 PCB
connects to 7977964 JB/6
Terminal
X1/3
motor relay "normally closed" - connects to
main wire feed motor
measure 0 to 24VDC (depends on wire speed
setting)
wrt 7977964 JB/8 in normal setting
Terminal
X1/4
solenoid relay "normally open" - connects to
spool gun solenoid
Terminal
X1/5
solenoid relay "common" - connects to 24VAC
supply
Terminal
X1/6
solenoid relay "normally closed" - connects to
main solenoid
CONNECTOR X2
Terminal
X2/1
wirespeed relay "normally open" - connects to
spool gun wirespeed pot wiper
measure 0 to 5VDC (depends on wire speed
setting)
wrt 7977964 JA/5 in spool gun setting
Terminal
X2/2
wirespeed relay "common" - connects to
wirespeed potentiometer input of 7977964 PCB
measure 0 to 5VDC (depends on wire speed
setting)
wrt 7977964 JA/5
Terminal
X2/3
wirespeed relay "normally closed" - connects to
main wirespeed pot wiper
measure 0 to 5VDC (depends on wire speed
setting)
wrt 7977964 JA/5 in normal setting
Terminal
X2/4
trigger relay - connects to trigger input of
7977964 PCB
Terminal
X2/5
trigger relay - connects to trigger input of
7977964 PCB
Terminal
X2/6
no connection
CONNECTOR X3
Terminal
X3/1
normal trigger input
measure approx 2.5VDC
wrt D11 anode when trigger open & approx
6VDC when trigger closed
wrt D11 anode
Terminal
X3/2
normal trigger input
measure approx 14VDC
wrt D11 anode when trigger open & approx
6VDC when trigger closed
wrt D11 anode
Terminal
X3/3
spool gun trigger input
measure approx 2.5VDC
wrt D11 anode when trigger open & approx
6VDC when trigger closed
wrt D11 anode
Terminal
X3/4
spool gun trigger input
measure approx 14VDC
wrt D11 anode when trigger open & approx
6VDC when trigger closed
wrt D11 anode
Terminal
X3/5
24VAC supply for board
measure approx 24VAC
wrt X3/6
Terminal
X3/6
24VAC supply for board
measure approx 24VAC
wrt X3/5