Vacon 20 CP, Installation, Technical And Maintenance Manual

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Mounting vacon • 32
Service support: find your nearest Vacon service center at www.vacon.com
3
a correction factor must be considered when the operating
Δ
T is different from what used
by the heatsink manufacturer in the measurement.
•
Surface finishing : the heatsink dissipation depends on the type of surface finishing of
heatsink itself (anodized/black surfaces dissipate differently from polished surfaces).
•
Heatsink attachment/orientation : heatsink attachment/orientation plays a significant
role under natural convection. It is recommended that the heatsink be installed to orient
the fins in a direction that will not block air movement under natural convection. Based
practical experience, if the heatsink is oriented in a wrong way, the thermal performance
will be approximately 25% worse under natural convection condition.
Note: to study the heat transfer in other cooling media of different geometry (e.g. cooling
plate without fins), please contact your local Vacon supplier to receive support in dimension-
ing method.
Taking account of the above, we recommend that the calculated R
HS
is multi-
plied by 0.7 to obtain a resistance value with a reasonable safety margin in order
to ensure tripless drive operation.