DIAGNOSTIC STATUS CODES
IT TRANSISTOR CONTROL
Page
18
April 2012
equivalent to the flatness of the control surface
(0.005” per linear inch). Use a straight edge or dial
indicator to verify the mounting surface.
The biggest hindrance to heat transfer is the
presence of rust, scale, weld splatter or paint on the
vehicle mounting surface. If any of these items are
noted, prepare the surface per the following
guidelines:
a) Clean the mounting surface with a rotary
wire brush until the metal surface is
exposed.
b) Using 80-100 grit emery paper, sand the
surface until the metal shines.
c) Flush the surface clean with an
appropriate liquid de-greaser or parts
cleaner.
Section 4.4.4 Application of Thermal Compound
Due to the minute differences in the control mounting
surface and the vehicle mounting surface, small
pockets of air will be created. These air pockets will
add to the overall thermal resistance of the interface.
To avoid these air pockets and improve thermal
conductivity, thermal compound must be applied
between the FSIP control base plate and the vehicle
mounting surface. The function of this compound is to
conform to surface discrepancies, filling gaps and
optimizing the metal-to-metal contact of the control
and the vehicle.
a) Prepare the two mounting surfaces
(control and vehicle) as indicated above.
b) Using a triangular notched trowel of 3/32”
(.09” +/- .01), apply the grease to the
vehicle mounting surface.
c) Use straight, non-crossing strokes of the
trowel to apply the compound.
d) Make multiple vertical passes until a
uniform consistency is achieved.
Krusin adhesive spreader model 00031
Vehicle surface after proper grease application
Section 4.4.5 Mounting the FSIP Control
a) Place the control unit with desired orientation
on mounting plate with mounting holes
aligned.
b) Move the control slightly in all directions to
eliminate voids and enhance the distribution
of the thermal compound.
c) Insert the all of the mounting hardware (4, 6
or 8 bolts, M6 or M8, necessary for the
mounting of the respective family of controls).
d) Tighten these bolts (as per sequence shown
in diagrams below) to half of the nominal
torque value
(7.5lb-ft).
e) Lastly, tighten the bolts to the nominal torque
value
(15 lb-ft),
following the same
sequence.
Calibrated torque wrench for hardware
installation