Any Single Phase 3HP Columbo Spindle Users Out There?

[porscheman]

Hi - I'm in the final stages of getting my PRTalpha machine up and running, and I have a question about the Delta VFD which drives the Columbo spindle on my machine.

As originally delivered by ShopBot (and by Precision Drive Systems for the VFD and spindle), this system was set up for 3 phase power. However, my shop only has single phase power and a quick call to ShopBot tech support prior to purchasing the machine indicated there might be a need to change to a different VFD optimized for single phase power.

However, once I got the machine home and started looking into the details, it now appears that the Delta VFD can be used in either single phase OR 3 phase applications. The unit is a model number VFD022B21A and the tech support people at PDS looked up this unit, including the specifics of the serial number (manufacturing date, etc.), and indicated that the VFD should provide a full 3HP to the spindle even in a single phase configuration.

So my question is whether anyone is using this specific Delta VFD model in a single phase application? Some empirical data from other Bot users would set my mind at ease on this point.

And finally, if this unit is suitable for single phase applications, I have a question about the wiring connections for the VFD, which are located behind the front panel of the VFD. In the 3 phase wiring scenario, L1/L2/L3 (red, white, black, respectively) each carried one of the three power legs to the VFD from the control box. Inside the VFD, on the L2 and L3 input terminals, two smaller black wires are connected to those terminals and go out to the spindle. ShopBot tech support had advised me to simply drop or ignore the L2 leg for single phase wiring, but if I do this, the small black wire connected to the L2 terminal inside the VFD will be connected to nothing. Is that a problem, and if so, can I just move that small wire to the L1 leg, which will be powered in the single phase configuration?

Anyone who could check inside their VFD faceplate and let me know how their wiring is configured could really help me out.

Thanks!

John

[gpari]

I have the same setup, I believe. I will check the machine in the morning. Though I won't be able to report back until afternoon, we are in the middle of a move and the bot is at the old building still. No phone or DSL there anymore.

[cnc_works]

I cannot help you with specific information on your brand and model, however, generally you can drive a VFD with single phase power to run a 3ph spindle, but you must downrate it by almost half. For example, you would need a VFD rated at 5 or 6hp to run a 3hp spindle. I understand that the harder you intend to push the spindle, the more you have to downrate it.

Donn

[porscheman]

Donn, your comments are exactly in line with what ShopBot tech support told me in my initial call to them, so I was prepared to swap my VFD out if necessary. However, when I contacted PDS to order a new VFD for my single-phase 3-horsepower application, they specified the same model number that I have now. At that point, they transferred me to their tech support department, where they looked up my model number and used number groups in my unit's serial number to confirm that this unit should output a full 3HP in a single-phase application. I'm paraphrasing here, but PDS said that in late 2003 or early 2004, Delta released the "B21" model (which replaced an earlier B23 model) that was rated at 3HP in either single phase or 3-phase applications. At 5HP and above, this situation may change. It even says on the label affixed to my VFD:

Input: 230V, 50/60Hz, 1-Phase or 3-Phase, Output: 3HP, 230V, 0-400 Hz

Now, I know absolutely nothing about VFDs and how they are specified, so the "difference of opinion" between ShopBot and PDS on this issue has been very confusing to me. I figured that if I could confirm (or refute) that other Botters are actually using this specific VFD model in a single phase configuration, then I could proceed with confidence.

Gabe, or anyone else, it would be great if you could check out your VFD and let me know.

Thanks!

John

[garyb]

Yes that model will run on single phase you use R(L1),S(L2) and the ground on the AC side

[gerald_martin]

John: I have had the 3HP Colombo with a Delta VFD-B since maybe 2004? It has worked well connected to single phase 220 although I am sure there are efficiency advantages to three phase power.

Gerald

[gene]

Gary is absolutely correct G = ground R1 is 1 leg and s is leg 2 for single phase power . You will love this spindle . If you are not familure with the spindle collet nut assembly make sure to snap the collet into the nut before installing t your bits..