Technical data

Manual – Gear Units and Gearmotors
147
8
Torque limit curves with inverter operation
Project Planning for AC Motors with Inverter
8.4 Torque limit curves with inverter operation
Thermally
approved torque
Note thermally approved torque in project planning for operation of DR, DT, DV
asynchronous AC motors with frequency inverter. The following factors determine the
thermally permitted torque:
•Duty type
• Type of cooling: Self-ventilation or forced cooling
• Base frequency f
base
= 60 Hz (460 V 댴) or f
base
= 120Hz (230 댴댴
Use the torque limit curves to determine the thermally permitted torque. The projected,
effective torque has to be less than the limit curve value. The following illustration shows
the limit curves for 4-pole DR, DT, DV asynchronous AC motors with f
base
= 60 Hz and
f
base
= 120 Hz. The following peripheral conditions apply to the shown limit curves:
•Duty type S1
• Supply voltage of the inverter U
supply
= 3 × 460 V
AC
• Motor in thermal class F
f
base
= 60 Hz
(460 V 댴/60 Hz)
The following diagram shows the limit curves for operation at f
base
=60Hz. The curves
are different for those motors with self-ventilation and those with forced cooling (=
optional forced cooling fan).
1. S1 operation with self-ventilation (= without forced cooling fan)
2. S1 operation with forced cooling (= with forced cooling fan)
3. Mechanical limitations for gearmotors
60850AXX
Figure 80: Torque limit curves for f
base
= 60 Hz
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 500 1000 1500 2000 2500 3000 3500
3.
2.
1.
rpm
T /T
R
460 V /60Hz