
40
Operating Instructions – Explosion-Proof AC Motors DR63/eDR63, DVE250/280
6
Safe operation of motors in category 3
Duty Types and Limit Values
6.3.3
Thermal limit characteristic curves – category 3GD
Thermal limit char-
acteristic curves
Thermal limit characteristic curve for inverter operation of 4-pole AC motors and
AC brakemotors in
connection:
Thermal limit characteristic curve for inverter operation of 4-pole AC motors and
AC brakemotors in
connection:
[1] 104 Hz limit characteristic curve
[2] 87 Hz limit characteristic curve
[1] 60 Hz limit characteristic curve
[2] 50 Hz limit characteristic curve
[1]
[2]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
400
800
1200
1600
2000
2400
2800
3200
3600
n [1/min]
M/M
rated
0,00
0,20
0,40
0.60
0.80
1.00
1.20
0
200
400
600
800
1000
1200
1400
1600
1800
2000
n [1/min]
M/M
rated
[1]
[2]
P
i
f
kVA
Hz
n