ADTRAN T200 H2TU-R Installation And Maintenance Manual page 19

4. Replace the remaining gas tubes in the same
manner. Each slot has four gas tubes.
5. Untag and reinsert the associated slot power
module at the CO.
6. Perform circuit tests to verify proper circuit
operation.
NOTE
If lightning is the suspected cause of circuit
pack failure, ADTRAN recommends
replacing all the surge arrestor gas tubes.
Door Gasket Replacement
The door gasket provides a weathertight seal. Routine
preventive maintenance includes cleaning the seal and
seal area when the cabinet door is opened. A
deteriorated or damaged gasket should be replaced
using the following procedure:
WARNING
Follow all manufacturers safety precautions,
directions, and other label warnings or
information when using gasket sealing
compound. Follow all application directions
to ensure a proper seal.
1. Remove damaged door gasket.
2. Thoroughly clean the gasket sealing area on the
door and the gasket flange using a soap solution.
Rinse and dry. Do not use solvents or chemical
agents that could damage the surface finish.
3. Install the replacement gasket to the gasket
flange with the joining ends at the bottom center
of the flange. Note that the replacement gasket
has vent holes. Install the gasket such that the
vent holes are on the cabinet interior side of the
gasket mounting flange.
4. Totally install the gasket to determine proper
circumference fit. If a small gap appears at the
joining ends the gasket can be slightly stretched
starting at the top and working towards the
bottom. Reverse this process if an overlap exists.
Continue this manipulation until the gasket ends
fit flush.
5. Where the gasket joins, on each side pull about 6
inches of gasket away from the flange.
6. An insert gasket "rope" provides a bonding
medium, gasket support, and end alignment.
61150090L1-5A
Provide adequate ventilation when using
sealant. Do not inhale vapors. Avoid contact
with the skin. Follow all sealant
manufacturers instructions.
The alignment rope is sized to fit equally
between the two ends of the gasket without
blocking the vent holes. During assembly keep
the rope equally positioned between the two
gasket ends.
Apply a small amount of sealant around one end
of the rope and slide it halfway into the gasket
core (either end).
Excessive sealant will decrease adhesion and
cause longer cure time. Inadequate sealant
will cause gaps allowing moisture penetration.
7. Apply a thin bead of sealant on the gasket
mating end. A proper seal requires a complete
sealant bead without breaks.
8. Carefully mate the two ends allowing the
alignment rope to slide into the gasket core on
the adjoining end until the two gasket ends meet
as seamless as possible. A small amount of
sealant should extrude around the mating edges.
9. Immediately install the gasket onto the flange to
maintain alignment and positive end contact.
Hold the gasket in this position for 2 minutes (or
manufacturer's directions).
10. Inspect the gasket joint. If any sealant gaps are
visible a thin coat of sealant can be applied to fill
the gap.
11. Follow the sealant manufacture's directions for
cure time (about 6 to 8 hours or until surface is
not tacky).
12. Do not close the door until the joint is totally
cured. This prevents the door from sticking to
the gasket on the next opening.
To ensure cabinet integrity it is important that the
joined surface that contacts the door when it is shut be
free of irregularities.
Section 61150090L1-5A, Issue 1
WARNING
CAUTION
CAUTION
19