
6
Startup
Parameter list of the MOVIFIT® compact inverter
Operating Instructions – MOVIFIT
®
compact
65
6.8.1
Description of inverter parameters
Parameter index 10546.23
Boost
Range of values:
0
– 50 V
A voltage boost when the drive is started increases the breakaway torque of the drive.
Parameter index 10546.38
UL motor current weighting factor
Range of values: 0 –
1.4
– 100
The UL motor protection function fulfills the requirements of standard UL 508C. The
motor current that is used in the UL motor protection function is the product of the cur-
rently measured actual current and the adjustable parameter index
10546.38 UL mo-
tor current evaluation factor
.
Parameter 860
PWM frequency
Range of values:
4 kHz
, 16 kHz
The nominal output of the inverter that is specified in the technical data applies to the
pulse width modulation frequency (PWM frequency) of 4 kHz.
The PWM frequency of 16 kHz is not possible at every operating point, and it is partic-
ularly dependent on the speed (stator frequency f
S
) and the thermal capacity utilization
(cooling air temperature) of the inverter.
The stator frequency f
S
is an important influential factor for operation with a PWM fre-
quency of 16 kHz. A 4-pole motor with a nominal motor voltage of 400 V and a rated
motor frequency of 50 Hz in a 400 V supply system can only be operated with a PWM
frequency of 16 kHz from a speed of 780 min
-1
.
For other motor/network voltage combinations, the required stator frequency f
S
from
which a PWM frequency of 16 kHz is possible should be calculated using the following
formula:
f
S
= V
line
/V
N
× f
N
/2
f
S
Stator frequency
V
line
Line voltage
V
N
Nominal motor voltage
f
N
Rated motor frequency
22527060/EN – 08/2017