Error Overload Low Speed - KEB COMBIVERT F5 Reference Manual

Overload Curves

2.10 Error Overload Low Speed

40
Load [%]
150%
105%
Permanent
current
(0 Hz)
At low speeds (below 3 Hz G-W housings, below 6Hz D-E housings), the rms current flowing
through the power transistors is higher, reaching 1.4 times the rated 60Hz rms value. This is
caused by the low-frequency sine wave created by the PWM. As a result, the continuous output
current must be limited at low speeds to prevent the power transistors from overheating. The
COMBIVERT F5 will drop the carrier frequency to 4kHz if necessary to be able to continue to
provide current to the motor. Once the output frequency rises above low frequency or the current
drops below the levels listed below, the carrier frequency will be returned to the higher value.
230V Maximum stall current (amps at 0Hz)
Inverter Carrier
Housing Frequency
13 14 15 15+ 16 17 17+ 19 20 21 23
E 8 kHz 24
16 kHz 16.8 16.8
G 8 kHz
16 kHz
H 8 kHz
16 kHz
R 8 kHz
16 kHz
U 4 kHz
8 kHz
16 kHz
480V Maximum stall current (amps at 0Hz)
Inverter Carrier
Housing Frequency
13 14 15 16 17 18 19 20 22 22+ 24 26 26+ 28
E 8 kHz 12 16.5 16
16 kHz 12
G 8 kHz
16 kHz
H 8 kHz
16 kHz
R 8 kHz
16 kHz
U 4 kHz
8 kHz
16 kHz
W 4 kHz
8 khz
16 kHz
E. OL2
0
Inverter Size
24
33 31 53
33 26 43
73 109 97
73 92 59
Inverter Size
10 10
19 22.0 21.5
8.4 9.5 -
42 50 54
25 30 36
E. OL
3 Hz
115 145 180
70 102 102
319
203
-
83
45
115 150
63 98
198 330 330
180 180 225
- - -
574
407
-