Braking Functions Of The Converter; Electrical Braking Methods - Siemens SINAMICS G120 Original Instructions Manual

Adapting the operating characteristic
Precondition
You require the following data to calculate the system-specific operating characteristic:
● Operating characteristics of the manufacturer
● System characteristics for five different flow rates.
Procedure
Proceed as follows to adapt the operating characteristic:
1. For the five different flow rates, calculate the delivery height requirement, referred to a
2. Enter the speeds into parameters p3321, p3323, p3325, p3327 and p3329.
3. Based on the flow rates and the associated operating characteristic of the manufacturer,
4. Enter the values into parameters p3320, p3322, p3324, p3326 and p3328.
You have adapted the operating characteristic, and you now obtain a precise result for the
energy saving.
8.7.3

Braking functions of the converter

8.7.3.1

Electrical braking methods

Regenerative power
If an induction motor electrically brakes the connected load and the mechanical power
exceeds the electrical losses, then it operates as a generator. The motor converts
mechanical power into electrical power. Examples of applications, in which regenerative
operation briefly occurs, include:
● Grinding disk drives
● Fans
Inverter with CU230P-2 Control Units
Operating Instructions, 11/2013, FW V4.6.6, A5E02430659B AG
– for pumps: Delivery height and power as a function of the flow rate
– for fans: Total pressure increase and power as a function of the flow rate
pump, which is directly connected to the line supply (n = 100%).
To do this, set the formula for the system characteristic the same as the formula for the
operating characteristic of the delivery height.
For a correspondingly lower delivery height, you only require a correspondingly low
speed.
calculate the power that the pump requires for the various flow rates when connected
directly to the line supply.
Setting functions
8.7 Application-specific functions
273