Hi to All,

I am Using CU240 E2-PN and PM240 55 KW [6SL3224-0BE35-5UA0] and 55KW Forced Cooling Motor in our Forging PRESS Application.

Control Mode is Vector Control Encoder Less [p1300=20]

We are connecting the Non Siemens Make Breaking Resistor [Resistance8.7 Ω, Rated power PDB 8.0 kW, Peak power Pmax 90 kW] to the Drive.

Now the Problem is The Breaking Resistor Was overheated, Temperature Increases up to 100 Deg, So The Cable Connected between the Drive and DBR Was Burned Out. I am also checked the Motor Cable, Motor and Drive Temperature everything in Normal only.

I ensure that there is sufficient clearance around the unit and there is adequate ventilation. 

During PRESS Stroke the DC Link Voltage is Increased UP to 760 Volts

To Activate the Dynamic Braking I set The Following Parameters in CU240 E2:-

P219= 8KW [BREAKING RESISTOR BRAKING POWER]

P1240= 0[Inhibit VDC Control for Vector Control]

P1531= -8 KW

P1254= 1[Vdc_max controller automatic ON level detection] 

// R1242= 770 V [Vdc_MAX CONTROLLER SWITCH IN LEVEL]

// I have changed the Parameter P219 up to 30 KW, But No Changes in DBR Temperature.

Also Is any parameter is Available to Identify the ON time of braking module Chopper. and Please Guide me How to Check the Power Module's Chopper Circuit

 I Have Attached My Starter Backup With This.

Kindly Help Me to Solve this Issue…

Thanks in Advance…..

Are you driving a flywheel?  It may be advisable to disable regeneration entirely during normal operation or at least decrease your negative current limit to something like 50%.  If you are using DB to stop the flywheel, then you will overheat the resister if you are using 150% current to stop the flywheel..  The problem is you are trying to control an incredibly large inertia, and DB is not the best way to do it. You cannot increase the regeneration current without burning up the chopper, but you can add 3 more resistors (series/parallel) to increase the net wattage of your DB.

I have always wanted an external DB controller for the PM240 so I had flexibility to solve this exact problem. 

Hi Jeff Casagrande,

Thanks For your Reply . I am using the Drive For Fly wheel . And We Bought the Suitable DBR For our 55 KW Drive[Resistance 8 Ω, Rated power PDB 8.0 kW, Peak power Pmax 90 kW] .Please Refer The Attachment .

Please Tell me this Over Temperature Happened By Any Wrong  Parameter  .

What is Parameter to reduce the Negative Current Limit???

How to Solve this Over Temperature Issue.

p1521 is the negative torque limit I think.  p1520 is positive.

It has been a long time since I was a commissioning engineer (AKA Mill Donkey) and I did a press, but here is what I remember....

During the press stroke, the speed will be mechanically limited.  The drive will go to positive current limit to try to compensate for this.  However, it cannot reach the desired speed for mechanical reasons.  Once the press stroke is finished, since there is a large speed error, the drive will still go to current limit to recover the speed.  When it hits the speed, it will overshoot, which is when the regeneration occurs.  This is bad, since you are taking energy out of the flywheel, only to add it back again during the press stroke.  Again, you are dealing with a large inertia, so nothing happens quickly.

I think I ended up limiting the current limits to 100% positive and 75% negative during operation.

Bear in mind, this was a LONG time ago and these were automotive stamping presses, but I think the principle is the same.

Dear Jeff

Thanks for your reply. Tomorrow I will change the parameter and let you know

loga

Dear Jeff

Thanks for your reply. Tomorrow I will change the parameter and let you know

 HI

How did you solved this problem 

As im facing the same issue