Selecting An External Heatsink - YASKAWA V1000 Installation Manual

6 Selecting an External Heatsink

6 Selecting an External Heatsink
This section describes the selection of a suitable external heatsink when using a V1000
Finless drive.
◆
Data Required for Heatsink Selection
The table below shows data that are needed to select a heatsink that suits drive and
application.
Symbol
Drive heat loss
P
Refer to V1000 Finless Drive Watt Loss Thermal Characteristics on page 14
Loss
the amount of heat loss from the heatsink plate of the drive.
Maximum heatsink plate temperature
This is the temperature at the surface of the heatsink plate. It can be monitored with U4-08. The
T
maximum allowable value depends on drive model.
HSP_max
CIMR-V BA
CIMR-V 2A0030~0069, CIMR-V 4A0018~0038: 80°C
T External heatsink ambient temperature (air temperature around heatsink)
Amb
Heatsink plate thermal resistance
Rθ
HSP
This value is 0.05 K/W
Thermal resistance between the heatsink plate and the external heatsink
Can be calculated by
Rθ
HSP-EHS
Rθ
HSP-EHS
A
th
λ
Comp
d
Comp
Rθ Thermal resistance of the external heatsink
EHS
22
, CIMR-V 2A0001~0020, CIMR-V 4A0001~0011: 90°C
d
Comp
=
λ
A
th
comp
Heat transfer area between drive heatsink plate and external heatsink
Note: Due to uneven heat generation across the heatsink plate (by arrangement
of internal components) the effective area for heat transfer is only ~70% of
heatsink plate area. This must be considered when calculating the thermal
resistance.
Refer to Dimensions on page 17
the heatsink plate.
Thermal conductivity of the heatsink thermal compound
Thickness of the thermal compound
YASKAWA ELECTRIC TOBP C710606 21D YASKAWA AC Drive - V1000 Finless Installation Guide
Description
for values of H and W to calculate the area of
to check