Lenze i750 - Information on Project Planning; Project Planning Process; Overcurrent Operation

Informaon on pr
oject planning
Project planning process
Overcurrent operaon
The inverters can be driven at higher amperages beyond the rated current if the duraon of
this overcurrent operaon is me limited.
Two ulisaon cycles of 15 s and 180 s are dened. Within these ulisaon cycles, an
overcurrent is possible for a certain me if aerwards an accordingly long recovery phase
takes place.
Cycle 15 s
During this operaon, the inverter may be loaded for 3 s with up to 200 % of the rated current
if aerwards a recovery me of 12 s with max. 75 % of the rated current is observed. A cycle
corresponds to 15 s.
Cycle 180 s
During this operaon, the inverter may be loaded for 60 s with up to 150 % of the rated
current if aerwards a recovery me of 120 s with max. 75 % of the rated current is observed.
A cycle corresponds to 180 s.
The monitoring of the device ulizaon (Ixt) triggers an error if the ulizaon value exceeds a
threshold of 100 %.
The maximum output currents correspond to the switching frequencies and the
o
verload behaviour of the inverters are given in the rated data.
In case of rotang frequencies < 10 Hz, the me-related overload behaviour
may be reduced.
The graphics shows a cycle. The basic c
ondions given in the table (graphics eld highlighted
in grey) have to be complied with in order that the inverter will not be overloaded. Both cycles
can be combined with each other.
t
I [%]
100
T
1
T
2
0
A
B
Overcurrent cycle Max. output current Overload me
Max. output current during
the r
ecovery me
Recovery me
A T
1
B T
2
s % s % s
Overcurrent cycle 15 s 200 3 75 12
Overcurrent cycle 180 s 150 60 75 120
Informaon on pr
oject planning
Project planning process
Overcurrent operaon
32