Lenze i750 - DC-Bus Connection; Important Notes

DC-bus c
onnecon
The inverters are designed for DC-bus connecon with a central AC system feed-in point.
Suppliers with various services are available for this purpose.
Parallel operaon of suppliers to increase supply power or braking power is permied.
Advantages of a DC-bus connecon
•
Ener
gy exchange between the inverters in motor operaon and in generator operaon.
•
Reduced supply power from the AC system
•
Design of the supply modules with lower rated power
•
Reduced braking losses in regenerave operaon
•
Only one AC mains connecon
•
Reduced wiring eort due to integrated busbar system
Important notes
The inverters in the network may only start oper
aon when the DC bus is fully charged. This
means that all inverters in the network must be supplied with 24 V.
NOTICE
The 24 V supply is not switched on for all inverters in the DC bus.
P
ossible consequences: Charging relay or charging hybrid can be destroyed.
▶
Feed all inverters in the DC-bus connecon via a common and stable 24 V supply.
▶
With split 24 V supply and fuse protecon: If a fuse responds, shut down the enre drive
train if possible to avoid cyclical voltage strokes in the DC bus.
Precondions f
or trouble-free DC-bus operaon
•
The r
ated values of the mains voltage or the DC bus voltage must be the same for all
inverters in the network.
•
The total DC power P
DC
must be provided by the supplier. 4Dimensioning ^ 43
•
The busbar system must not be overloaded:
•
Max. connuous current: 120 A.
•
Max. overload: 180 A for 60 s.
•
Unloading phase aer overload: Max. 90 A for 120 s.
•
Braking operaon with suppliers connected in parallel:
•
The switching thresholds of the brake choppers must be set to the same value.
•
The control of the brake chopper must be synchronized by master-slave connecon.
4Braking operaon ^ 39
Informaon on pr
oject planning
DC-bus connecon
Important notes
35