MICROMASTER - fixed frequencies

Hey everyone,

I trying to use the "fixed frequencies" mode on a micromaster inverter (MM3 serie),

here is the operation manuel :https://www.vfds.com/manuals/siemens-micromaster-manual.pdf

First of all, you have to know I got back this equipment from a second-hand, so this is not brand new...

So I used the reset factory parameters (P944 to 1).

I wired 3 switch on DIN1 an DIN2 as 2 different entries for 2 distinct frenquencies, and DIN3 for an inverting rotation button.

Then I changed different parameters listed below :

- P006 = 2 (fixed frequency)

- P009 = 3 (all R/W param)

- P015 = 1 (automatic resart)

- P041 = 200 Hz

- P042 = 100 Hz

- P043 = 50 Hz

- P051 = 6 (fixed frequencies)

- P052 = 6

- P053 = 3 (inverting sw)

I have several problems :

1. The equipment does not working until I press the RUN button.
This is not an industrial behavior to me...

2. Every fixed frequencies are differently setted up but the motor I wired for my experimentation seems work at the same speed whatever frequency I put on P041to 043...

3. The inverting switch does not seems to work.

4. I trust the frequency is supposed to displays on the LCD when the motor is supplyed (like it is setted up by default; P001 = 0) but it's not happening.

Please anyone knows this equipment and could help me on this ?

Thanks in advance, cheers.

Olivier.

Hello,

if I understood correctly, you need to run on 3 frequencies in forward and in reverse mode. With your settings there is no start signal, which you need to start the motor.

With setting p51 = p52 = p53 = 17 you can binary choose all 7 fixed frerquencies and motor automaticaly start with frequency selecting. With parameter p45=6  you can invert first 3 ones. And finaly you have to copy needed frequencies to p44, p46 and p47.

With combination of digital inputs you can select forward or inverted frequencies.

See corresponding description and tables for these parameters in your manual.

With regards

Martin

 Hello @Martin,

Martin472

if I understood correctly, you need to run on 3 frequencies in forward and in reverse mode. With your settings there is no start signal, which you need to start the motor.

With setting p51 = p52 = p53 = 17 you can binary choose all 7 fixed frerquencies and motor automaticaly start with frequency selecting.

That's not exactly the mode I want to use, what you describe is the "Binary fixed frequency control (fixed frequencies 1 - 7)" as mentionned in the manual.
with indeed P051 = P052 = P053 = 17

In my case, I want use the fixed frequencies, that means: P041 to P043 are valid if P006=2 and P051 to P053 = 6

see screenshot attached

Concretly, I want to have pushbutton switches (with DIN1,DIN2 and DIN3) ;
one pushbutton by frequency, means 1 push = 1 frequency (fixed speed).

Anyway I'll keep the advice with the reverse mode, thank you for that tip.

Above you mentionned my setting does not have a start signal, I did not read such a thing in the manual...
In the 4.4 chapiter, it is written:
"If the motor does not start up when the ON command has been given, check that the ON command is valid, check if a frequency setpoint has been entered in P005 and check that the motor specifications have been entered correctly under parameters P081 to P085.
If the inverter is configured for operation via the front panel (P007 = 001) and the motor does not start when the RUN button is pressed, check that P121 = 001 (RUN button enabled)."

Also it is written for P007=0 :
"0 = Front panel buttons disabled (except STOP,
uparrow and downarrow). Control is via digital inputs (see parameters P051 - P053).
uparrow and downarrow may still be used to control frequency provided that P124 = 1 and a digital input has not been selected to perform this function."

Do you think fixed frequency mode cannot have an automatic starting without pressing START button?

Thank you for your replies ! ;)

Hello,

I'm sorry I didn't notice mode 18, which is like mode 6, but run signal not required.

As of your first description of required functionality, where two DI choose frequency (and starts motor in this mode) and third DI will inverse direction, you can try set p51 = p52 =18 and p53 = 3.

With regards

Martin