Siemens SIMOTICS-T 1FW68, Engineering Manual

Page: 51 / 180

Mechanical properties
3.1 Cooling
1FW68 radial segment motors
Configuration Manual, 04/2017, 6SN1197-0AE02-0BP1
51
Figure 3-2 Influence of the coolant intake temperature
Heat-exchanger unit
Use a cooling system to ensure an intake temperature of 35 °C. Several stator segments can
be connected to a cooling system (heat exchanger). The heat-exchanger units are not
included in the scope of delivery.
The cooling power is calculated from the sum of the power losses of the connected stator
segments. Adapt the pump power to the specified flow and pressure loss of the cooling
circuit.
For a list of companies from whom you can obtain heat exchanger units, see the appendix.
Dimensioning the heat-exchanger unit
The power loss generated in the motor during continuous operation causes a thermal flow to
take place. The surrounding machine assembly dissipates a small percentage of this thermal
flow. The cooling system coolant dissipates the majority of this thermal flow. The cooling
system must dissipate 85 % to 90 % of the power loss that occurs. Appropriately dimension
the cooling system rating.
If you operate several stator segments simultaneously on one cooling system, then the
cooling system must be able to dissipate the sum of the individual power losses.
In continuous operation, only load the motor so that the continuous rms torque M
eff
does not
exceed the rated torque M
N
. In continuous operation, it is not permissible for the operating
point in the M-n diagram to be above the characteristic for S1 duty. As a consequence, the
maximum rms power loss P
V
only reaches the rated power loss P
V,N
.