Lincoln Electric IDEALARC CV-300 Service Manual page 75

F-36
MOUNTING OF STUD TYPE DIODES TO ALUMINUM HEAT SINKS (CONT'D)
PROCEDURE
1. Loosen the appropriate diode nut
and remove the diode that is to be
replaced.
2. Clean the area on the heat sink
around the diode mounting surface
using a putty knife, or similar tool,
DO NOT SCRATCH THE DIODE
MOUNTING SURFACE.
3. Polish each heat sink's mounting
surface using NO. 000 fine steel
wool. Wipe surface clean with a lint
free cloth or paper towel.
4. Inspect the mounting surfaces of
each new diode. Remove all burrs
and wipe clean. Do not use steel
wool or any abrasive cleanser on
the diode mounting surface.
5. Apply a thin (0.0003" to 0.0007")
uniform layer of E1868 (Dow
Corning 340) heat sink compound
to the heat sink mounting surface.
a. Do not apply compound to
b. The diode threads must be
6. Tighten the diode nuts to the speci-
fications in the following table.
a. The nuts for diodes with steel
b. The nuts for diodes with copper
c. Turn a minimum of 1/2 turn
TROUBLESHOOTING & REPAIR
diode stud or mounting threads.
clean and free of defects so that
the nut can be finger tightened
before applying torque. A "slip"
type torque wrench must be
used to tighten the diode nut.
studs are to be started by hand
and then torqued as per the fol-
lowing table.
studs are to run on all the way
by hand then torqued as per the
following table.
more while torquing per the
table.
IDEALARC CV-300
DIODE STUD FOOT-
SIZE POUNDS
3/4 - 16 25-27
3/8 - 24 10±.5
1/4 - 28
F-36
INCH-
POUNDS
300-324
125+0/-5
22-25