BONFIGLIOLI active Installation Manual

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4 Thermal properties of the heat sink
The heat in the frequency inverter due to the energy dissipation of the electronic com-
ponents (rectifier and IGBT) must be dissipated to a heat sink via the cold plate of the
frequency inverter.
The capacity to dissipate this heat mainly depends on the size of the heat sink surface,
the ambient temperature and the heat transmission resistance. An increase of the heat
transmission rate can only be realized to a certain extent by increasin
g
the surface o
f
the heat sink. An additional increase of the heat dissipation by increasin
g
the heat sin
k
is not possible.
T
he frequency inverter should be mounted with the cold plate on a heat sink with the
lowest thermal resistance possible.
4.1 Thermal resistance
The thermal resistance R
th
is calculated from the difference between the maximum
heat sink temperature and the ambient temperature, referred to the ener
g
y dissipation
of the frequency inverter. The ambient temperature to be considered refers to the
immediate environment of the frequency inverter.
v
umaxk
th
P
TT
R
−
=
Max. permissible heat sink temperature of the frequency inverter T
kmax
= 75 °C
Ambient temperature of the cold plate of the frequency inverter T
U
= 35 °C
Difference between the maximum heat sink temperature and the
ambient temperature (T
k max
-T
U
)
ΔT = 40 K
Energy to be dissipated by the heat sink P
v
= depends on
type
Note: During installation, the following items must be considered in order to mini-
mize the thermal resistance:
- The installation surface must at least be as large as the cold plate sur-
face.
- The contact surface must be plane and have a good thermal conductiv-
ity.
-
T
he thermal limits of the frequency inverter and the cold plate must be
considered when determining the dimensions.
For the max. permissible thermal resistance R
th
and the device-specific energy dissipa-
tion P
v
, refer to the following table. The thermal resistance R
th
is given in the unit Kel-
vin per Watt (K/W). Additionally, the thermal radiation of the frequency inverter is
indicated.

BONFIGLIOLI active Specifications

General

Brand	BONFIGLIOLI
Model	active
Category	DC Drives
Language	English