PowerFlex 753 won't power up.

Hi guys,

How to check whether the PowerFlex 753 50HP, 460VAC is good or not. It won't power up. I have 460VAC going to the drive. I checked fuses three times. The original ones seemed to be OK but I replaced them to avoid this mistake.

Normally when PowerFlex "blows up" I can smell it but nothing on this one. I Don't smell anything, don't see any signs of anything being fried.
Any suggestions>

All help is appreciated. Thank you

If there's power on the line inputs, and it's not powering up. Then the drive is typically no good. You don't always have a burnt smell on a failed drive.

Is the connection to the faceplate OK? Fans turn on?

You can check if the converter part is working by checking the DC bus voltage with a multimeter. At 480 Volts AC you should get somewhere between 650 and 680 Volts DC.

Assuming this is a Frame 5 drive, (50HP Heavy Duty rated), the rectifier at that size uses an SCR based bridge for precharge mitigation rather than precharge resistors. So because SCRs are active devices, they have a firing board that ramps the voltage when you initially apply power to the drive. If you lose the firing board or the line sensing circuit for it, you get no voltage on the DC bus. And because the drive derives it's control power from the DC bus instead of a separate power supply, you don't have a display to tell you that's what's wrong. Hence the meter reading as suggested.