[tonebag]

I recently purchased a 4 x 6 CNC router from Craigslist that came with a HSD 4.5 kw spindle and a Sunfar C300A VFD 2.2 kw. It is Chinese made for sure. I brought someone with me to test it before I bought it and the spindle was running fine. When I finally got the machine home and hooked it up, it was fine. I am running it off 220V single phase in my garage. I was told it would operate on 220V single phase power and it was tested and working under those conditions before purchasing. The second time I turned it on, I heard a loud "pop" coming from the controller cabinet. I opened it up and noticed a faint wisp of smoke coming from the VFD. The only thing I noticed afterwards was the switches on the controller were in the ON position before I turned on the main breaker in the panel. When the switches were off first, then turned on after the breaker, there was no issue. Not sure if that had something to do with it. I currently have it running on a 20 A breaker but Big Al was kind enough to inform that I would need to double that at least.

Anyway, looks like I fried my VFD so now I need a replacement. But from what I've been been told, there is no VFD that will provide enough power to my spindle from a 220V 1PH input. I've been told I need 3 phase input and that ain't happening. The other option is to replace my spindle with a 3 HP model which I'm hoping I won't have to.

Is it possible to underpower my spindle and run it with just 3hp? (i've been told it will work for about 10 minutes before blowing up the vfd) In case you are wondering, I intend to only machine hardwoods, mdf and various plastics.

I found a VFD on ebay that claims to take 220V single phase input and creates a 3 phase 4.5 kw (6hp) output. that sounds too good to be true but if it is, I'll get it. here is the link - 4 5KW 6hp CNC Inverter VFD 1 Phase 220V 21A 1000Hz for Engraving Spindle Motor | eBay

I also found another VFD from a more reputable manufacturer (thanks again Big Al) but it outputs only 3 hp. I can get this one if I am able to underpower the 6hp spindle. here is the link Telemecanique Altivar 28 AC VFD ATV28HU41M2S303 240VAC Single Input 3HP OUT | eBay

If anyone out there can help me out with a recommendation on a replacement VFD or alternative solution to my problem, I would greatly appreciate it. I bought this thing to make some money and now the wife is getting on my case because it's sitting there doing nothing but taking up space in the garage.

I included the specs of my current VFD and spindle below in case anyone has any experience with either.

Cheers,
Tony



VFD info:
model Sunfar C300A-2S00-37L
Source 1PH 220V 50/60 HZ
Output 7.0 KVA 17.5A


Spindle info:
Model: HSD AT/MT 1090-100 Asynchronous 3 phase motor
V 220 KW 4.5 (5.4)
HZ 300 HP 6.11
RPM 18000 A 16.8
Is: F Poll: 2
TA 20 degrees C
Serv: S1 (S6 40%)

[mactec54]

tonebag

No you can not run a 4.5Kw spindle like this with a 2.2Kw VFD, that is most likely why it fried, but you may also have had something else wrong in the wiring, as power it up it should not of fried, the VFD

A 3Ph VFD drive can be run on single phase, it does not have to be single phase rated VFD,to use your 220v single phase, so get the right VFD to do the job, when using a 3Ph VFD you want it to have a larger capacity, than what the spindle is 5.5Kw to 6Kw is where you want to be for your 4.5Kw spindle

[tonebag]

Hi Mactec,

Thanks for taking the time to reply and for confirming that I can run a 3ph VFD with 1ph input. That is such a relief! I checked the wiring again and there was no ground terminal which would probably explain the vfd getting fried.

I am still unclear about the size of the VFD because when you say larger capacity, past threads and some manufacturers have recommended that the 3ph VFD be rated for at least double the capacity if running on 1ph input. So for a 4.5 kw spindle that would mean I am looking at a 9kw VFD.
The only problem is that I can only find VFDs rated for either 10HP or 15HP. Just not sure which one to get.

Can anyone please point me in the right direction?

Oh, and my apologies to Al the Man for referring to him as Big Al in my initial post.

[Al_The_Man]

Oh, and my apologies to Al the Man for referring to him as Big Al in my initial post.

I have been called worse!
Al.

[mactec54]

tonebag

I think you will find that most quality 3 Ph VFD Drives, have a max derating of 40% when running on Single Phase. I have found that a 1/3 more than the motor Hp/size has always been enough, so in your case 6Kw will be fine

For Grounding if the VFD does not have any Ground Terminals, then your Ground wire's need to attach to were the VFD is mounted, there is usually 4 mounting holes around the base of the heatsink, this is where your Ground wires would be attached

[Al_The_Man]

Normally VFD's that allow 1ph or 3ph operation have a larger capacitor bank to allow for the reduced energy of rectified 1ph as opposed to 3ph of the same voltage.
Rectified full wave three phase has a % ripple of only ~4%-5%, against 100% for 1ph before smoothing.
And a ripple freq of 360° as opposed to 120° 1ph.
Al.

[tonebag]

Hey Al,
Just letting you know that the vfd was working fine. turns out it was my computer power supply that went pop and not the vfd. regardless, it was only rated for 3.7kw so I decided to swap it out with one that is rated for 5.5 kw. However, the Sunfar E550 I replaced it with doesn't seem to be working properly - I must have it set up incorrectly.