Troubleshooting & repair, Active scr test (continued) – Lincoln Electric IDEALARC R3R-500 User Manual
Page 63
TROUBLESHOOTING & REPAIR
F-29
F-29
IDEALARC R3R
ACTIVE SCR TEST (continued)
TEST PROCEDURE
1. Disconnect the main input supply power to
the machine.
2. With the 5/16” nut driver, remove the case
top and sides. Remove the screws holding
the front panel and lower the panel.
3. Disconnect the welding cables from the
welding output terminals.
4. Locate and remove molex plug P4 from con-
trol board G2206. See Figure F.16.
If the machine has control board G1575, dis-
connect the individual gate leads G1, G2,
and G3 and also lead #204. See Figure F.17.
5. Locate and remove molex plug P5 from
snubber board M15370. See Figure F.18. If
the machine has snubber board M14215, it
will be necessary to label and disconnect
lead #204 from the output shunt. Be sure to
disconnect the #204 lead that runs
between the snubber board and the out-
put shunt.
6. Locate and remove lead #204 from resistor
R3 (40 ohms, 50 Watts). See Figure F.19.
FIGURE F.16 – CONTROL BOARD PLUG
P1 AND P3 LOCATIONS
FIGURE F.19 – RESISTOR R3 LOCATION
FIGURE F.18 – SNUBBER BOARD PLUG
P5 LOCATION
RESISTOR R3
R3R CONTROL
G2206 - [
]
Plug P3
Plug P4 (Removed)
FIGURE F.17 – CONTROL BOARD
G1575 LEAD LOCATIONS
R3R CONTROL
G1575 - [
]
G1
G2
G3
M15370-[ ] SNUBBER
Plug P5