Danfoss VLT FC Series Installation Manual page 3

IGBT Module Replacement for D1h–D8h Drives
Installation Guide
2.2 Installing the IGBT Module
THERMAL INTERFACE
A proper thermal interface is required between the IGBT module and heat sink. Failure to follow these instructions results in a
poor thermal bond and causes premature IGBT failure.
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Ensure that the environment is free of airborne dust and contaminants while applying the thermal grease.
HEAT SINK DAMAGE
A damaged heat sink can cause a drive to malfunction. A clean, undamaged mounting surface allows proper thermal dissipation.
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Take care not to scratch or damage the heat sink when cleaning and servicing the drive.
Refer to the service guide for IGBT disassembly procedures. To install replacement IGBT modules, use the following steps.
1. Clean the heat sink using a cloth and solvent or isopropyl alcohol to remove debris and remaining thermal grease.
2. To ensure that the thermal grease is not expired, check the expiration date on the packaging. If expired, order a new
syringe of thermal grease (p/n 177G5463).
3. With the syringe, apply a layer of thermal grease to the bottom of the IGBT module in the pattern shown in
It is not required to use the whole syringe, but excess thermal grease is not a problem.
1
2
Illustration 1: IGBT Thermal Grease Pattern
1 Bottom surface of IGBT module
2 Thermal grease
4. Place the IGBT module on the heat sink, and twist it back and forth to spread the thermal grease evenly on the IGBT and
the heat sink surface.
Align the mounting holes in the IGBT module with the holes in the heat sink.
5.
Insert the mounting screws and hand tighten them. The IGBT module requires either 4 or 10 screws to fasten it to the
6.
heat sink.
Using a manual torque wrench to avoid over torquing the screw, follow the fastener tightening sequence shown in
7.
Illustration 2. Slowly tighten (maximum 20 RPM) all screws to 50% of the torque values listed in
Repeat the same tightening sequence and slowly tighten (maximum 5 RPM) all screws to 100% of the torque value.
8.
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N O T I C E
N O T I C E
Installation
Illustration
Table 2.
AN341428219214en-000201 / 130R0383 | 3
1.