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.
WARNING
Provide adequate ventilation when using sealant. Do not inhale vapors. Avoid contact with the skin. Follow all sealant manufacturers instructions.
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.
CAUTION
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).
CAUTION
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 | 19 |
