GASKET 2772500 - Caterpillar

Required Tools
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355-8579 Grease As for thermal application (1) Needle with thermal grease (2) Cleaning cloth (3) Spatula
Installation kit
Torque wrenchRequired Parts
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Typical thyristorsTable 1 lists the required thyristor for your application.
Table 1
Type    60 kVA    120 kVA    
AC Bypass
Single UPS     367-4285
90 Amp
1400 v     353-8595
160 Amp
1400 v    
AC Bypass
Parallel UPS     353-8595
160 Amp
1400 v     353-8594
250 Amp
1400 v    
Inverter
Single UPS
Parallel UPS     367-4285
90 Amp
1400 v     353-8595
160 Amp
1400 v    Procedure
High voltage may be present. Work on this equipment must be performed by authorized trained personnel. Failure to disconnect the power source before performing maintenance or removing modules exposes personnel to electrical potential. Bodily contact with electrical potential will cause serious personal injury or death.
Electrostatic discharge can damage integrated circuits or semiconductors if you touch the connector pins. When not in use, keep modules in static shielded bags. Follow these guidelines when you handle modules:Allow a minimum of 5 minutes for capacitors to discharge.Touch a grounded object to discharge static potential.Wear a wrist-strap grounding device.Do not touch the connector pins.Do not touch circuit components inside the module.If available, use a static-safe work station.
Remove power from the UPS by following the appropriate shutdown routine. Allow at least 5 minutes for the capacitors to discharge to remove any stored energy.ReferenceOperation and Maintenance Manual, SEBU8516, "Single UPS Startup and Shutdown" and "Parallel UPS Startup and Shutdown".
Disconnect the wires and disconnect the ribbon cables from the circuit board.
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The circuit board has been removed.
Remove the circuit board.
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The bus bar has been removed.
Remove the bus bar that is attached to the thyristors.
Remove the thyristors.
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Heat sink with cleaned surface
Using the cloth (2), clean the grease from the surface of the heat sink. Refer to Illustration 1.
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The grease has been applied to the thyristor.
Apply the thermal grease to the base of the thyristor using the needle (2). Refer to Illustration 1.
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Spatula (3A) Straight face (3B) "Another module" face
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The grease has been spread on the thyristor.
Spread the grease into a thin layer by using the straight face (3a) of the spatula. Refer to Illustration 7.Hold the face at a slight angle to the base of the thyristor and spread the grease evenly across the face.
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The spatula should be held perpendicular to the thyristor.
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Grease has been properly applied to the thyristor.
Hold the "Another module" face (3b) of the spatula perpendicular to the base of the thyristor and drag the spatula across the base. Refer to Illustration 7. This action will create a grooved surface in the grease. Refer to Illustration 10.
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The thyristors are mounted on a 60 kVA single UPS.
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The thyristors are mounted on a 60 kVA parallel UPS.
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The thyristors are mounted on a 120 kVA single UPS.
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The thyristors are mounted on a 120 kVA parallel UPS.
Install the thyristors on the heat sink by using the M5x16 screws (4). Refer to Illustration 11 through 14.Note: Torque the screws to 5.4 N m (47.8 lb in).
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Detail of installation for a 60