Troubleshooting & repair, Scr removal and replacement (continued) – Lincoln Electric IDEALARC CV-300 User Manual
Page 78
F-39
TROUBLESHOOTING & REPAIR
F-39
IDEALARC CV-300
8.
Go to procedure that matches cap
screws. NOTE WHICH THREAD IS
ON YOUR CAP SCREWS BEFORE
PROCEEDING TO THE ASSEM-
BLY PROCEDURE. Two different
designs of leaf springs and housings
have been used to clamp the SCR
to the rectifier. The two different
designs can be identified by the size
of the leaf spring. One design uses
a 1/2 inch wide leaf spring and the
other uses a 5/8 inch wide spring.
The different designs require differ-
ent assembly and clamping proce-
dures. The assembly procedure will
be different depending upon the
thread on the cap screws. A 1/4-28
thread requires a different tightening
procedure than a 1/4-20 thread.
PROCEDURE FOR THE 1/2
INCH WIDE SPRING
1.
Place a piece of sleeving around
each bolt.
2.
Insert bolts thru the leaf spring.
Orient the leaf spring so that it's
ends are curved upward toward the
bolt heads. See figure F.21.
Pressing on the bolt heads should
produce a "rocking" motion of the
spring in its housing. If the spring
does NOT rock it is installed upside
down. Remove the spring and turn
it over. Check for "rocking" motion.
See Figure F.21.
Fig. F.21 - 1/2" Wide Leaf Spring
3.
Insert bolts and leaf spring into the
plastic housing.
4.
Insert clamp assembly thru heat
sinks. Install nuts. Tighten clamp
nuts equally on bolts until finger
tight. (See Figure F.22. Heat sinks
may not be exactly as pictured.)
Fig. F.22 - Clamp Assembly.
5.
Re-inspect the SCR for proper seat-
ing.
SCR REMOVAL AND REPLACEMENT (CONTINUED)
SPRING CURVATURE
EXAGGERATED
1/2"
HOUSING
HEAT SINK
1/4-28 OR 1/4-20
CAP SCREW
SLEEVING
S.C.R.
HEAT SINK
PLAIN WASHER
HEX NUT
LEAF
SPRING