Powerflex 753 run off 110 for programming purpose?

[jeff pugh 0]

I am setting up a control cabinet with a large drive network on IP and would like to power up the drives with 120vac just to run the electronics. Has anyone done this? I have heard it can be done but don't have any specifics. I think i just need to get enough voltage to power the DC bus to an acceptable level.

[ScottC 8]

You need a 20-750-APS Auxiliary Power Supply module that plugs into the drive and a 24VDC power supply. Because of the module width, I think it actually takes up two slots.

[jeff pugh 0]

1 hour ago, ScottC said:

You need a 20-750-APS Auxiliary Power Supply module that plugs into the drive and a 24VDC power supply. Because of the module width, I think it actually takes up two slots.

That is great! Thanks for the quick reply. I have two slots available also. I will check out the datasheet.

[jeff pugh 0]

I think I worded the question wrong. I have a 480v drive and want to run the drive off single phase power; 120v or 208v - just the electronics and comms (control power) for setup, not run motors, just setup. I think the 20-750-APS Auxiliary Power Supply is just for I/O right? Anyone run a 3 phase drive off single phase for this purpose?

[ScottC 8]

From A-B reference manual page 41:

Auxiliary Power Supply The optional Auxiliary Power Supply module, 20-750-APS, is designed to provide power to a single drive’s control circuitry in the event incoming supply power to the drive is removed or lost. When connected to a user supplied 24V DC power source, the communication network functions remain operational and on-line. A DeviceNet program can also continue to run and control any associated input and outputs. The auxiliary power supply module is designed to power all peripherals, I/O, and connected feedback devices.

The installation instructions also mention the 20-750-APS on page 266.

 

[jeff pugh 0]

Hi Scott, I didn't see all that detail in the 750 manual - I was looking in the install area. Unfortunately, I will only have one slot available.

I got this idea from a Rockwell Tech Connect guy working from his home in Seattle. He can run small motors as well. You can also run it off 220v or run a 240V drive. He says he does this all the time:

Edited 4 Mar 2016 by jeff pugh
Add detail

[TimWilborne 108]

I'll have to write up a wiring diagram for this. It is my test transformer that I feed 120VAC and can switch between 240 and 480 with a selector switch for testing controls.

[jeff pugh 0]

Ahh, brilliant! I can do that; great idea. What kVA transformer did you use to run your drive? Have you tried to run a small motor?

I will give it a try. We have a 1.5kVA transformer and some .25HP 3 phase motors. I will need to power three PF753 drives. Thanks also Scott. I'll post the results.

[TimWilborne 108]

It is still single phase so you can't run the drives but they usually will power up.

[jeff pugh 0]

I have been told that as long as you have good DC bus voltage and input current availability, a small motor will run. Not true?

Edited 4 Mar 2016 by jeff pugh

[TimWilborne 108]

If a drive doesn't have phase loss protection or there is a way to disable it then yes, a drive can run roughly at roughly 1/2 the hp rating on single phase.  Some drive even have single phase ratings.  The Automation Direct GS2 drives we use in our VFD control panels have single phase ratings up to 3 hp though I've build Hitachi units up to 50hp single phase.

Here is another way to make three phase from single phase.  I don't use it for testing control systems but I've heard of a lot of backyard machine shops using these.  I've built one to test and it works surprisingly well.

http://www.theautomationstore.com/3-phase-electrical-power-from-single-phase/

[jeff pugh 0]

I ran in to a dilemma - what to do with the ground. I don't think i want a floating ground on the drive. This is what i think i should do.

[jeff pugh 0]

Update: The drive control power ups from a .5kVA transformer and is drawing about 900mA idling - great! I have not configured the drive to try to run the motor but this is next. I will be connecting to it with Connected Components Workbench. I will take your advice TW and disable phase-loss. Standby...

Edited 7 Mar 2016 by jeff pugh

[jeff pugh 0]

Update: So, from a 120 volt receptacle and .500kVA control transformer, I am now able to run my drive, communications, and actually operate a small test motor, a SEW-Eurodrive (460V, .25HP,  0.55A) motor at 1500 RPM's. The 120 input to the transformer draws 1.1A and the 460V to the drive is drawing 270mA. The Powerflex 753 bus voltage is 600 VDC and is outputting about 272 VAC to the motor. Thanks for the help.