Rockwell Automation 1336S-F-E-T-R User Manual
Service Instructions
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Transistor and Thyristor (SCR)
Replacement for 1336 PLUS, PLUS II,
FORCE, IMPACT and REGEN Drives.
Description These instructions cover the proper method of replacing transistor and
SCR modules in the 1336 family of drives. Failure to properly prepare
the mounting surface or to torque the components to rated specifications
will result in decreased service life of the replacement components.
Contents Description Page
Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Surface Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Thermal Grease Requirements. . . . . . . . . . . . . . . . . . . . . . . . . 3
Torque Mounting Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety Precautions
ATTENTION: Some printed circuit boards and drive
components may contain hazardous voltage levels.
Remove and lock out power before you disconnect or
reconnect wires, and before you remove or replace fuses
and circuit boards. Verify bus voltage by measuring the
voltage between +DC and - DC on Terminal Block TB1.
Do Not attempt to service the drive until the bus voltage
has discharged to zero volts.
ATTENTION: Potentially fatal voltages may result from
improper useage of oscilloscope and other test equipment.
The oscilliscope chassis may be at a potentially fatal
voltage if not properly grounded. If an oscilliscope is used
to measure high voltage waveforms, use only a dual
channel oscilliscope in the differential mode with X100
probes. It is recommended that the oscilliscope be used in
the A minus B Quasi-differential mode with the
oscilliscope chassis correctly grounded to an earth ground.
2 Bulletin 1336 Service
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ATTENTION: This assembly contains parts and sub-
assemblies that are sensitive to electrostatic discharge.
Static control precautions are required when servicing this
assembly. Component damage may result if you ignore
electrostatic discharge control procedures. If you are not
familiar with static control procedures, reference AllenBradley Publication 8000-4.5.2 Guarding Against
Electrostatic Damage, or any other applicable ESD
protection handbook.
Surface Preparation After removing the transistor or SCR modules from the drive, the heat-
sink and replacement modules must be prepared using the following
method to ensure proper heat transfer and operation of the replacement
components.
1. Remove all old heat transfer compound from the surface of the
heatsink using a tool such as a rubber spatula that will not mar the
heatsink surface. Remove any remaining residue with a soft cotton
cloth and a cleaning fluid such as Essex Cleaning Fluid, Brownell
OS-3 by Dow Corning Co. (Mineral spirits may also be used if
Essex cleaning fluid is not available).
2. Use a non-marring cleaning pad such as a Scotchbrite by 3M
remove any oxidation from the face of the heatsink. DO NOT use
steel wool or sandpaper to clean the surface of the transistor/SCR
baseplate or the heatsink, as they could scratch or score the surface
which will impede heat transfer from the transistor to the heatsink.
3. Follow the oxidation removal with a final cleaning of both the
heatsink and the module baseplate with cleaning fluid and the soft
cloth.
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NOTE: Thermal compound must be applied immediately to both surfaces as detailed in the following Installation section to prevent oxidation from reoccuring.
If a cleaning agent other than Essex by Dow Corning is used, make
certain it leaves No residue on the heat transfer surfaces.
Installation Install the transistor or SCR module to the heatsink as follows:
1. Apply a liberal coating of themal compound (AOS 52022) to the
transistor or SCR module base plate using the amount of 6 gram
blister packs (part number 196261) recommended in Table 1 for
your particular device.
2. Apply the thermal compound until the metal surface is no longer
visible. Do not allow any foreign particles or contamination to
collect on the thermal grease. The nominal thickness of the grease
coating should be about 0.005 inches or 0.127 millimeters.
3. Mount the transistor or SCR module on the heatsink, pressing and
rotating in a slight circular motion to better seat the transistor onto
the heatsink and distribute the grease more evenly.
4. Apply slight pressure and attempt to lift the module back off the
heatsink. If the module does not easily separate from the heatsink,
the thermal interface is correct. If the module easily separates from
the heatsink with no suction effect, this could be due to insufficient
grease or foreign particles on either the module base plate or the
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