10.3
Overload capability of the inverter
Overload capability is the property of the inverter to temporarily supply a current that is higher
than the rated current to accelerate a load. Two typical load cycles are defined to clearly
demonstrate the overload capability: "Low Overload" and "High Overload"
Definitions
Base load
Constant load between the accelerating phases of the drive
Low Overload
High Overload
● LO base load input current
Permissible input current for a "Low
Overload" load cycle
● LO base load output current
Permissible output current for a "Low
Overload" load cycle
● LO base load power
Rated power based on the LO base load
output current
● HO base load input current
Permissible input current for a "High
Overload" load cycle
● HO base load output current
Permissible output current for a "High
Overload" load cycle
● HO base load power
Rated power based on the HO base load
output current
If not specified otherwise, the power and current data in the technical data always refer to a
load cycle according to Low Overload.
We recommend the "SIZER" engineering software to select the inverter.
You will find additional information about SIZER on the Internet: Download SIZER (
support.automation.siemens.com/WW/view/en/10804987/130000
Load cycles and typical applications:
"Low Overload" load cycle
"High Overload" load cycle
The "Low Overload" load cycle assumes a
uniform base load with low requirements
placed on brief accelerating p phases. Typi‐
cal applications when designing according to
"Low Overload" include:
● Pumps, fans and compressors
● Wet or dry blasting technology
● Mills, mixers, kneaders, crushers,
agitators
● Basic spindles
● Rotary kilns
● Extruders
The "High Overload" load cycle permits, for
reduced base load, dynamic accelerating
phases. Typical applications when designing
according to "High Overload" include:
● Horizontal and vertical conveyor
technology (conveyor belts, roller
conveyors, chain conveyors)
● Centrifuges
● Escalators/moving stairways
● Lifters/Lowerers
● Elevators
● Gantry cranes
● Cable railways
● Storage and retrieval machines
Technical data
10.3 Overload capability of the inverter
SINAMICS G120C converter
404
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34263257B AF