MAINTENANCE NOTICE
MN-97-001
DIGITAIR® SBU Model 6695-V
Battery Compartment Corrections
Problem Description
This maintenance notice details corrections to
the battery compartment on the SBU Model
6695-V End-of-Train Device used by Norfolk
Southern. The following two (2) problem issues
are addressed:
1. Potential electrical arcing can occur when
inserting the Sealed-Lead Battery into the
SBU. This happens when the battery
terminals make contact with the two (2) outer
fastening nuts used to secure the battery door
to the unit.
2. Insertion and/or removal of the Sealed-Lead
Battery into the SBU’s battery compartment,
on some units, may be difficult or impossible,
due to an excessively tight fit. This is caused
by tolerance variations in the size of the
battery itself and the opening of the SBU
battery compartment.
Corrective Actions
A. Correction of Battery Electrical Arcing:
To correct the battery arcing problem, replace
the two (2) outer screws and nuts securing the
battery door with 1/8” stainless steel button head
pop rivets. These rivets can be obtained under
US&S part number J490037-0039 or original
manufacturer number EMHART #SSD43SSBS.
The middle mounting screw and nut should be
retained.
B. Correction of Battery Fit:
To ensure that all batteries fit into the SBU
battery compartment, US&S has provided
Norfolk Southern with a customized “Sizing Jig”.
Use this jig to slightly spread open the battery
compartment per the procedure below:
1. Place the Sizing Jig into the middle of the
battery compartment ensuring that the right
and left plates rest on the inside bottom
surface of the compartment. The “R” and “L”
stampings should be facing upwards and be
visible.
2. Using hand pressure, turn the hex nut portion
of the jig clockwise until the jig has spread
open and is tight against the inside walls.
3. Using a wrench, slowly torque the hex nut in
the clockwise direction to slightly spread open
the battery compartment (approximately 1/8”).
DO NOT OVER TORQUE.
4. Unscrew and remove the Sizing Jig. Try the
battery for fit. The battery should easily slide
in, but should be snug.
5. If the battery does still not fit, place the Sizing
Jig at each end of the battery compartment
and repeat steps 1 to 4. Continue this
process until the battery fits.
End of procedure
For additional information about End-of-Train
equipment or ordering parts, contact US&S
Customer Service at 1-800-652-7276.
For technical support, contact the R.A.I.L. Team
at 1-800-652-7276.
