3 Installation
3.3 Assembly
DB1 variable frequency drive
11/20 MN040031EN
Eaton.com
52
3.3.2 Cooling measures
In order for variable frequency drive DB1 to operate reliably, sufficient cooling
is crucial. An essential aspect of efficient cooling is its thermal resistance,
including optimal thermal transfer between the cooling surface of the DB1
variable frequency drive and the cooling system (e.g. heat sink, mounting
plate, or machine housing). A heating plate is required for this purpose, and
the correct torque (2 Nm) must also be used for the fixing screws (3x M4x20).
Figure 29: Cooling measures
The permitted temperature on the cooling surface of the variable frequency
drive depends on the switching frequency set using P-17.
The variable frequency drive automatically reduces the switching frequency
as soon as a certain temperature is exceeded (see table below).
Table 8:
Temperature on the cooling surface
Temperature on
the cooling
surface
Response
65 °C
Automatic switching of the switching frequency from 32 kHz to 24 kHz
70 °C
Automatic switching of the switching frequency from 24 kHz to 16 kHz
80 °C
Automatic switching of the switching frequency from 16 kHz to 12 kHz
85 °C
Automatic switching of the switching frequency from 12 kHz to 8 kHz
94 °C
Shutdown due to over-temperature when P-17
≧
8 kHZ
97 °C
Shutdown due to over-temperature when P-17 = 4 kHZ
1
3
2
2 Nm
(17.7 lb-in")
3 x M4 x 20
