Description, technical data
2.9 Cooling
A5E01083943A AB
Siemens AG Operating Instructions 2.02 1FW4
37
[ID 808.01]
2.9.2 Air cooling
Description
The 1FW4 motors have two cooling circuits. Intensive, effective cooling is achieved using
these.
● The fan inside the motor provides air circulation between DE and NDE. This cools, in
particular, the stator winding heads, the magnetic rotor and the bearings.
● The heat from the internal air is dissipated across the surface of the motor housing. The
external fan provides an even cooling air flow over the complete speed range of the
1FW4 motor. The external fan unit is attached axially on the NDE.
Coolant supply temperature
The standard motors are designed in accordance with EN 60034-1 for operation up to a
coolant temperature of 40°C, assuming compliance with all of the motor data. If you operate
the 1FW4 motor in higher ambient temperatures and/or install it at altitudes higher than
1,000 m above sea level, you must reduce the specified rating torque of the motor using
the
k
HT
factor. In doing this, note the derating factors in the following table.
Table 2-10 Derating factors AS a function of the ambient temperature and site altitude
Factor
k
HT
for site altitude above sea level Ambient
temperature °C
1,000 m 1,500 m 2,000 m 2,500 m 3,000 m
30 1.07 1.04 1.02 0.98 0.95
35 1.03 1.02 0.98 0.94 0.92
40 1 0.97 0.93 0.90 0.87
45 0.95 0.93 0.88 0.86 0.83
50 0.91 0.88 0.83 0.81 O. R.
55 0.85 0.83 O. R. O. R. O. R.
60 0.8 O. R. O. R. O. R. O. R.
The ambient temperature is rounded up to 5°C. The site altitude is rounded up to 500 m.
[ID 1140.00]
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