Hi all!!!

I have a problem at a site where a EUROTHERM 584 SV 18kW, is not able to restart a fan if the fan is not at standstill. If it is spinning even at low speed, upon starting it gives DC link overvoltage alarm. Fan motor is OK as far as I can see and measure. System was working fine for years. My only taught is that capacitors are drying up and voltage spiking is causing this fault. From what I have been told VSD is more than 5 years old.

Any taughts?
Thanks!

 

I've run into this with flywheel drive motors.
Look through the parameter set for that drive and look for something called "flying restart" or similar. I know it exists in some Rockwell drives. The drive will ramp up the output frequency without any real power output to figure out how fast the motor is spinning. It then starts its ramp at that frequency.

 

Hi joseph, thanks for the reply. Problem is that what ever set up was, it was working fine for yeras. And problem started on it's own.

 

Hi all!!!

I have a problem at a site where a EUROTHERM 584 SV 18kW, is not able to restart a fan if the fan is not at standstill. If it is spinning even at low speed, upon starting it gives DC link overvoltage alarm. Fan motor is OK as far as I can see and measure. System was working fine for years. My only taught is that capacitors are drying up and voltage spiking is causing this fault. From what I have been told VSD is more than 5 years old.

Any taughts?
Thanks!

Look for "fly catching" and make sure that is enabled.
When your Motor is spinning, the drive needs to know its "homing" position. In sensor less mode, the spinning rotor will generate some EMF, which in turn will increase the DC Link during regenerative breaking enabled OR if the DBR (Dynamic Breaking Resistor) is defective, or any other mechanical parameter changes such as inertia & its not yet updated / retuned in the drive.

Also over a period of time, memory gets corrupted due to aging of components, especially in high fatigue thermal cycling & high humid areas. In such case, reloading the last good known parameters could help.
Hope it helps.

Let us know how its progressed & keep us posed on your findings.