YASKAWA
TOEPC7106170YB YASKAWA AC Drive GA500 Installation & Primary Operation
49
Symbol
Value
Rθ
HSP-EHS
A
th
H = 128 mm
D = 68 mm
A
th
= 0.7 × 0.128 m × 0.068 m = 6.1 × 10
-3
m
2
λ
Comp
2.0 W/(m∙K)
Thermal conductivity of Oil-based compound X-23-7795 from Shin-Etsu
Chemical Co., Ltd.
d
Comp
100 μm
Recommended compound thickness (when applied)
Select External Heatsink by Thermal Resistance
Replace the value of
into the formula in
Select External Heatsink by Thermal
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.
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
EHS
= 1.1 K/W (T
HSP
= 68.95 °C).
◆
Removing/Reattaching Covers
DANGER
Electrical Shock Hazard. Do not examine, connect, or disconnect wiring on an
energized drive. Before servicing, disconnect all power to the equipment and wait for the time specified on
the warning label at a minimum. The internal capacitor stays charged after the drive is de-energized. The
charge indicator LED extinguishes when the DC bus voltage decreases below 50 Vdc. When all indicators
are OFF, measure for dangerous voltages to make sure that the drive is safe. If you do work on the drive
when it is energized, it will cause serious injury or death from electrical shock.