Siemens A1 User Manual

MICROMASTER  Applications Handbook 

35 

The following examples are based on applications where Siemens Drives have 
been successfully applied.  In some cases the circuitry and parameter settings 
have been simplified. The settings and parameters refer to Siemens 
MICROMASTER MM420s. 

 The Application uses a MIDIMASTER to control a ventilator fan in an application 
where the fan is manually adjusted.  By using the Advanced Operator Panel, 
mounted on the cubicle door using the appropriate mounting kit, a simple control 
solution without additional cabling is achieved.  The operator can then adjust the 
fan speed to suit ventilation requirements simply by pressing the buttons on the 
panel. 

·  At frequencies below 50 Hz there is significant energy saving.  Power is 

proportional to the cube of speed, so a reduction in frequency to 45 Hz will 
result in a saving of about 30%.  Mechanical systems offer little or no saving. 

·  Acoustic noise is reduced when the fan is run below base speed. 

·  The complete assembly can offer IP54 protection when the MICROMASTER is 

mounted in a suitable cubicle. 

·  The Advanced Operating Panel (AOP) offers a simple control solution; panel 

labelling, additional switches etc. are not needed. 

·  Closed loop control can be easily enabled using on board PI controller. 

Motor: 

18.5 kW 400 V 3-phase induction motor 

Control System:  Advanced Operator Panel (AOP) 

Drive: 

MICROMASTER  MM420 11 kW 400 V 

Drive Control 
Interface: 

Keypad control with start, stop and motorised potentiometer 
(reverse and jog functions disabled). 

 

 

M

MM420

11kW

MICROMASTER

Advanced Operator Panel

(Door Mounted)

Supply and RS485

Connection

3-Phase, 400 V

U, V, W Output

and Earth