Lenze i750 - Page 44

Requirements for the supplier
The supplier must be able to provide the mean value of the individual P
a
v
power outputs on a
permanent basis.
The overload requirements must be within the permissible range:
•
3-min cy
cle: 1 min overload with 150% and 2 min recovery me with 75%.
•
15-s cycle: 3 s overload with 200% and 12 s recovery me with 75%.
Determining the power requirement
Determine the motor power requirement of the DC bus c
onnecon based on the rated power
of the motors, their eciencies and the power losses of the inverters:
( )
( )
n
Mot
i
DC v
i
i 1
i
P
P P
=
ì ü
ï ï
= +
å
í ý
h
ï ï
î þ
PDC Total motor power requirement of
the DC bus c
onnecon
PMot Rated power of a connected motor
PV Power loss of an inverter
η Motor eciency
n Number of inverters in the DC bus
connecon
Informaon on pr
oject planning
DC-bus connecon
Dimensioning
44