Lincoln Electric IDEALARC SP-255 Service Manual page 71

F-18
STATIC SCR RECTIFIER ASSEMBLY TEST
TEST PROCEDURE
1. Disconnect main AC input power to
the machine.
2. Disconnect Plugs J3 and J6 from the
G2801 Control Board. This electri-
cally isolates the SCR bridge assem-
bly. See Figures F.2.
J2
J7
J4
J5
J6
FIGURE F.2 - Remove Plugs J3 and J6
to Perform Static SCR Rectifier As-
sembly Test.
3. Test with an Analog Volt-Ohm meter
that capacitors have completely dis-
charged.
4. Disconnect leads X2 and X3 from the
negative capacitor bank using a 1/2"
open end wrench. See Figure F.3.
TROUBLESHOOTING & REPAIR
SP-255 CONTROL
G2801
J8
J3
J9
IDEALARC
NEGATIVE
CAPACITOR
BANK
BUSS BAR
FIGURE F.3 - Location of Leads X2
and X3.
5. Separate leads X2 and X3 from the
negative capacitor bank buss bar.
Be sure there is no electrical contact.
See Figure F.3.
® SP-255
F-18
LEADS
X2 AND X3