External Heatsink Selection Methods; Select External Heatsink By Thermal Resistance - YASKAWA GA500 Series Installation Manual

8 External Heatsink Selection
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External Heatsink Selection Methods

Keep the drive heatsink plate temperature lower than the maximum temperature in all ambient
temperatures. Select an applicable external heatsink for your application.
Figure 8.1 shows the thermal transfer principle from the drive heatsink plate to the ambient air
of the external heatsink.
A - Drive
B - Heatsink Plate
C - Thermal Compound
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Select External Heatsink by Thermal Resistance

Use the formula to calculate the maximum thermal resistance Rθ
Select an external heatsink with a smaller thermal resistance than Rθ
Make sure that the dimensions of the external heatsink are close to the drive dimensions (H ×
W). If the thermal resistance of the external heatsink is large, but the dimensions of the external
heatsink are near the external dimensions of the drive, select one of these external heatsinks:
• External heatsink with more fins
• External heatsink with longer fin shape
Consider the installation environment of the drive and correct the thermal resistance Rθ
the external heatsink. Dust and unwanted material can decrease the cooling capacity of the
external heatsink.
Note:
Apply correction factors to the thermal resistance values listed in the specification of the external heatsink in these
cases. For details, contact the external heatsink manufacturer.
• The heatsink height and width dimensions are much larger than the drive heatsink plate dimensions.
• When you install multiple drives on one heatsink.
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Figure 8.1 Thermal Equivalent Circuit Diagram
YASKAWA TOEP C710617 0SA YASKAWA AC Drive GA500 Installation Manual
D - External Heatsink
E - Heatsink Plate Temperature
EHS_max
EHS_max
of the external heatsink.
.
of
EHS