GE Industrial Solutions ASTAT-CD Plus Solid-State Starters - Manual (Page 5)

ASTAT-CD Plus Service Instructions
5
Reassembly
Step 17. Reassemble the new Protection Board to the
starter with screws, CT leads and jumper.
Reassemble the Power Supply Board, Logic
Board, cover and terminal connections using
Steps 11, 5 and 6.
To replace SCR modules
(Sizes F, G,H and I)
NOTE: POWER MUST BE REMOVED
BEFORE SERVICING.
Disassembly
Step 18. Remove the Logic Board, Power Supply
Board and Protection Board using Steps
13-16.
Step 19. Remove MOVs and bus bars from the SCR
Module to be replaced (Figure 13).
Step 20. Remove the mounting screws at each end of
the SCR Module and remove the SCR
Module. Retain all parts and hardware
removed from the SCR module for
reassembly.
Current
transformers
SCR modules
MOV
Bus bars
Figure 13. Removing bus bars
Figure 14. SCR Modules removed
Assembly
Requires tools (#2 Phillips head screwdriver, Allen
wrench and Torque wrench for screws), Scotchbrite
or equivalent abrasive, a mild solvent to clean surfaces
and Electrolube 2 GX or equivalent thermal grease.
The mounting surface of the heatsink must be flat
and clean (i.e., bare metal) and the SCR surface must
be clean. Thermal compound must be coated on all
mating surfaces between the SCR package and the
heatsink. Care must be taken to use the specified
torque for mounting the SCR package.Step 21.
For SCR module mounting, clean the heatsink
surface with a fine abrasive such as Scotchbrite,
remove all particles from the surface of the heatsink
and wipe the SCR mounting surface with a mild
solvent. Apply a light coat of thermal compound such
as Electrolube 2 GX to both the SCR and heatsink
surfaces. Place the contact face of the SCR package on
the mating heatsink surface and move the SCR
package back and forth several times to distribute the
thermal compound evenly over the contact surfaces.
Step 22. Use the screws provided to attach the SCR
package to the heatsink. Tighten the screws
alternately to the specified torque
requirement for the SCR package.
Torque requirements are as follows: Tighten
the screws through the SCR package to
heatsink— 44 in lb.