MN-05-002
March 2005
Page 1 of 2
Sealing the Top Metal Plate
on the
AMTRAK High Speed Train ATC Enclosure
Reason for Notice
The possibility of water leaking into the
electronics cardfile of the ATC enclosure has
been detected. Leakage may occur from the
top of the enclosure around the metal-to-metal
seal between the enclosure and the square
mounting plate/ heatsink for the
Melcher/Power-One power supply. Water
leaking into the cardfile may cause damage to
one or more printed circuit boards in the
cardfile and result in subsequent ATC circuit
failures.
This Maintenance Notice is being issued to
preclude any potential problems.
Maintenance Procedure
1. Remove power to the ATC enclosure.
2. Remove the ATC enclosure from the
mounting compartment. (Refer to the
vehicle maintenance manual for
instructions regarding ATC enclosure
removal.)
3. Once all mounting hardware has been
removed, slide the ATC enclosure out of
the mounting compartment to gain access
to the top of the enclosure.
NOTE
Cables located on the right hand
side of the enclosure may need to
be disconnected to be able to get
sufficient clearance.
4. Thoroughly clean around the edges of the
metal mounting plate on the top of the
enclosure with isopropyl alcohol to remove
any dirt, grease, etc. (Refer to Figure 1 for
the location of the mounting plate /
heatsink.)
5. When the surface has been cleaned, place
a bead (about 1/8 inch thick) of RTV
sealant (US&S Part Number J041943)
around the perimeter of the metal mounting
plate to seal the metal-to-metal area.
6. Allow the RTV to cure for 1 to 2 hours.
Visually inspect the bead to verify that it
has cured and that a good seal exists
between the top of the enclosure and the
edges of the metal mounting plate.
7. Reinstall the enclosure into the train
compartment by reversing the above
removal process.
8. Power up the unit and confirm ATC
enclosure is operating properly. (The lights
and the display on the ATC unit will
energize and begin to function.)
Criticality
There is no need for an accelerated
modification schedule. This modification can
be made as the trains are cycled through the
Periodic Inspection (PI) process.
Technical Support - RAIL Team
Technical questions or
information requests
regarding the contents
of this Maintenance
Notice should be
directed to the
RAIL
Team
via telephone at
1-800-652-7276
or via
Internet e-mail at
