Select External Heatsink By Thermal Resistance; Examine Feasibility Of The Selected External Heatsink - YASKAWA GA500 Series Installation Manual

8 External Heatsink Selection
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Select External Heatsink by Thermal Resistance

Replace the value of
Resistance on page 24.
The thermal resistance of the external heatsink "EF(98) L: 150" is 1.6 K/W, so you can use it.
Yaskawa recommends the external heatsink "EK (95) L: 150" to prevent overheat if there is a
temporary temperature increase or a decrease in the cooling capacity of the external heatsink
because of dust and unwanted material.
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Examine Feasibility of the Selected External Heatsink

The thermal resistance of the external heatsink "EF (98) L: 150" is 1.6 K/W. You can use the
formula to calculate the heatsink plate temperature.
The temperature of the heatsink plate is lower than the maximum value of 90 °C, so you can use
it. Because the thermal transfer area is 70% of the drive mounting area, and the environmental
conditions can change because dust and unwanted material can decrease the cooling capacity of
the external heatsink, Yaskawa recommends "EK (95) L: 150" heatsink to achieve Rθ
K/W (T = 68.95 °C).
HSP
26
Table 8.1 into the formula in
YASKAWA TOEP C710617 0SA YASKAWA AC Drive GA500 Installation Manual
Select External Heatsink by Thermal
= 1.1
EHS