Hi,

                            I commissioned G120 drive with cu240e-2n, pm240 45kw rating, it is for pump application, motor is running well, the problem is when i stop the motor some times i am getting F7404 Fault in drive, i increased dc link max  voltage monitoring delay time and ramp down time but still i am getting the fault, please give some idea to solve the problem..

no dynamic braking resistor is fixed

With regards,

Dhinagaran, V

Hi all, 

I am also facing the same problem on 22 kW on g120.,cu 240e-2. In my case , suppose I will give any setpoint eg 200,the rpm is getting increased automatically. And within sometime vfd got tripped. Showing f 7404 fault. 

If anyone has any solution . please reply.

Thank you

Regards 

Prasanna

Hello,

Which is the control mode? Have you noted above points & checked why the DC voltage increases? What is the application? Please check below points.

Thank you very much for your reply.

I think the fault is coming because of cable length. The cable length is about 500 m.

For that reason we have used "filter" . Should we choose any parameterization?

It is simple PUMP and FAN application.

Thank you,

Regards 

Prasanna

This is way too long unless you have a dedicated filter which allows cables that long (Scheffner f.e).

Siemens du/dt filters for that frame size allow for max. 300 m unscreened cables if I remember correctly.

Prasanna_Prasanna

Thank you very much for your reply.

I think the fault is coming because of cable length. The cable length is about 500 m.

Regards 

Prasanna

 Shift drive near to motor. For such long length even filters or any parameter also will not help.

Thank you very much for reply.

I am using "OUTPUT WAVE FILTER,115A, 3PHASE, 400V AC"   from SCHAFFNER.

Any other options can I try?

kindly find the attached alarm report.

Thanks in Advance. 

For this application with a 45kW pump I suggest selecting the drive to OFF2, coast to stop.

For the dive on a 500 Metre cable, the capacitive losses in the cable will prevent this installation being reliable. I have used sinus filters for long cable’s, but the power losses require some oversize for the drive, which needs to be specified at the design stage, and they do make a noise, acoustic noise that is.

Operating PWM supplies from a variable speed drive, at these lengths depends upon the capacity of the electrical cable, an element which is due to physical dimension, construction, and quality of manufacture, which makes these installations unpredictable.