Lincoln Electric IDEALARC CV-305 - Manual (Page 79)

SCR REMOVAL AND REPLACEMENT PROCEDURE
(CONTINUED)
TROUBLESHOOTING & REPAIR F-47 F-47
IDEALARC® CV-305
8. Go to procedure that matches cap screws. NOTE
WHICH THREAD IS ON YOUR CAP SCREWS
BEFORE PROCEEDING TO THE ASSEMBLY
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 different assembly and clamping
procedures. The assembly procedure will be dif-
ferent depending upon the thread on the cap
screws. A 1/4-28 thread requires a different tight-
ening 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.17. 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.18.
Figure F.17 - 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.18. Heat sinks may not be
exactly as pictured.)
Figure F.18 - Clamp Assembly.
5. Re-inspect the SCR for proper seating.
SPRING CURVATURE
EXAGGERATED
1/2"
HOUSING
HEAT SINK
1/4-28 OR 1/4-20
CAP SCREW
SLEEVING
S.C.R.
T SINK
PLAIN WASHER
NUT
LEAF
SPRING
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