wallace7777 Posted October 21, 2012 Report Posted October 21, 2012 I have an Eation Cutler Hammer VFD SV9040AS-5M0A00 with 480V 3Phase 60 amp input and want to use it for testing aircraft fans. It will supply power through a test panel with its own contactor and control switch and has monitoring for amps, volts, and Hertz. I originally had an old military vfd that produced the power to the test panel but it isn't very inefficient. I need to program the drive to produce 115v per leg at 400 Hertz, no accell time as I want the drive to be at full power and ready to apply power through the test panel contactor. I know I have to change set point 1.2 to 120hz to make be able to run at 400hz. I am just having a problem setting all the parameters to make the drive do what I want. i changed the parameters I thought was right and used the monitoring program to test the drive however, the screen says the right values I want but when testing with meter, I am not getting what the monitoring program within the SVDrive program says. The VFD used to control a motor and I just want to use it as a power supply with full load available when needed. I made changes to the program going through a PC (I have the SVDrivecable interface because my LCD went out) but i am not getting the 115v per leg I need... it is still showing 400 or so volts for some reason. I still want to use the remote switch to turn the VFD on as it is already installed on 25 & 26... is the shunt across 11 & 13 for this fundtion or did this tell the controller to operate by the pot that was there? i am not going to use the pot as I want constant unadjusted power when it is turned on and constant until it is turned off... is this right for my aplication? Maybe someone can just send me all the settings and I can just program it and be done? Just need help setting the programming if someone could help me I would greatly appreciate it! Thanks in advance with any help with this, Eric Quote
OkiePC Posted October 30, 2012 Report Posted October 30, 2012 I am not familiar with that brand of VFD, but my general knowledge may be of some help. The DC bus voltage in the drive is determined by the input voltage. You can't change it. 480 vac generates a DC bus voltage of about 675vdc. The drive uses this DC bus and switches it very rapidly to simulate AC voltage and power, but if you look at the output with a scope, you will see that each individual spike is full voltage, no matter how the drive is programmed. The pulse width modulation of those full voltage signals is what allows the drive to simulate a lower voltage. Are you reading 400v from the vfd display or with an instrument of some sort? It is possible you still have something set up incorrectly, and it is also possible that your measurement method is the problem, and the drive is doing what you want. Paul Quote
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