Democestes
Industrial
- May 11, 2009
- 1
OK Guys and Gals,
I have some serious issues with Power Factor correction and DC Drives.
Two years ago we shut down a large part plastics Blow Molding Plant. The Plant ran at most 15 heads on 15 Presses , ranging from massive 50lb Sterling Double press/Double heads down to small 10 lb blowmolding machines, and a plant full of auxillary equipment. 2 months after the shutdown, we reopened the plant using only the 50lb Double/Double. We did not downsize any of the support equipment: (i.e. we still have the 3750kva transformer 5.39% impedance, as well as the 1600kvar Capacitor bank.) THe Double/Double runs two independant 300 hp DC Motors with 590+ Eurotherm drives. This did ok until about 6 months into operation as the new company. Then we started having issues with the DC Motors. We would fry one motor, then the other, then we would lose a drive then the other, and the cycle would repeat. Needless to say this became a costly endevor, rebuilding motor after motor and Drive after Drive. I searched as many engineering forums that I could find and Talked with as many Sales Engineers that would talk to me. (Note: I am not an engineer, I am a Maintenance man who is tasked to be the engineering support for the plant. I turned off the PF bank and some of my problems went away, but started getting beat down with PF Penalties. The owner has invested heavily in the drives that we have and will not consider changing over to an AC setup.
I want to change out the Main Transformer to a 1750 kva 13.2 ~ 480wye We have installed 330kva drive isolation transformers ahead of the line reactors to the drives, However they kept melting down the B phase and couldn't handle the load.
Any Help would be greatly appreciated
I have some serious issues with Power Factor correction and DC Drives.
Two years ago we shut down a large part plastics Blow Molding Plant. The Plant ran at most 15 heads on 15 Presses , ranging from massive 50lb Sterling Double press/Double heads down to small 10 lb blowmolding machines, and a plant full of auxillary equipment. 2 months after the shutdown, we reopened the plant using only the 50lb Double/Double. We did not downsize any of the support equipment: (i.e. we still have the 3750kva transformer 5.39% impedance, as well as the 1600kvar Capacitor bank.) THe Double/Double runs two independant 300 hp DC Motors with 590+ Eurotherm drives. This did ok until about 6 months into operation as the new company. Then we started having issues with the DC Motors. We would fry one motor, then the other, then we would lose a drive then the other, and the cycle would repeat. Needless to say this became a costly endevor, rebuilding motor after motor and Drive after Drive. I searched as many engineering forums that I could find and Talked with as many Sales Engineers that would talk to me. (Note: I am not an engineer, I am a Maintenance man who is tasked to be the engineering support for the plant. I turned off the PF bank and some of my problems went away, but started getting beat down with PF Penalties. The owner has invested heavily in the drives that we have and will not consider changing over to an AC setup.
I want to change out the Main Transformer to a 1750 kva 13.2 ~ 480wye We have installed 330kva drive isolation transformers ahead of the line reactors to the drives, However they kept melting down the B phase and couldn't handle the load.
Any Help would be greatly appreciated