Lincoln Electric IDEALARC CV-300 Service Manual page 78

F-39
SCR REMOVAL AND REPLACEMENT (CONTINUED)
8. Go to procedure that matches cap
screws. NOTE WHICH THREAD IS
ON YOUR CAP SCREWS BEFORE
PROCEEDING TO THE ASSEMBLY
PROCEDURE.
designs of leaf springs and hous-
ings have been used to clamp the
SCR to the rectifier. The two differ-
ent 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
different assembly and clamping
procedures. The assembly proce-
dure 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.
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.
SPRING CURVATURE
EXAGGERATED
See Figure F.21.
TROUBLESHOOTING & REPAIR
Fig. F.21 - 1/2" Wide Leaf Spring
3. Insert bolts and leaf spring into the
Two different
4. Insert clamp assembly thru heat
HEAT SINK
HEX NUT
See figure F.21.
Fig. F.22 - Clamp Assembly.
5. Re-inspect the SCR for proper seat-
1/2"
IDEALARC CV-300
plastic housing.
sinks. Install nuts. Tighten clamp
nuts equally on bolts until finger
tight. (See Figure F.22. Heat sinks
LEAF
SPRING
S.C.R.
HOUSING
HEAT SINK
PLAIN WASHER
may not be exactly as pictured.)
ing.
F-39
SLEEVING
1/4-28 OR 1/4-20
CAP SCREW