View Full Version : How to connect 2.2KW Inverter VFD?

08-10-2012, 07:39 PM
Hi guys,

I have a 2.2KW spindle and inverter from CNC 4 U. I've read the manual but the English is not very clear. Can anyone help about the details for how to connect it together?

Here is the back of the VFD


I think from reading the manual that RST (pins 1,2,3) can accept 3-phase mains, but for 2-phase I just connect to any 2 pins, say R and S. Does that sound right? Mains earth will obviously go to pin 9.

It mentions in the manual about a breaking resistor but it says "P.Pr - Connector for breaking resistor and in another part shows pins P and N with the breaking resistor across them. So what do you think, does the resistor on my inverter go across P+ and PR (pins 4,5). What sort of resistor do I need? Maybe 10R and 25W?

The spindle motor connects to UVW (pins 6,7,8) but my motor is unmarked. It has 4 pins, which I have numbed in my picture. Pins 1,2,3 connect to each other through 1.6R (I assume the coils of the motor) and pin 4 doesn't seem to connect to anything. The outer part of the plug connects to the body of the motor so I assume this is where the ground goes. If I connect UVW to pins 1,2&3 on the motor does it matter which order I connect them - i.e. pin 1 is U or pin 1 is W?

Thanks chaps! :calm:


08-10-2012, 07:49 PM
WHOA... if this is a 3phase to 3phase inverter DONT CONNECT IT to a single phase supply.... at best it wont work, at worst some magic smoke might escape.... it should say LNE or at least LN if its a single phase in.

On your other questions....

Yes 1,2,3 are UVW and the order doesnt matter. If the motor runs backwards swap ONE pair around.

Breaking resistors are nice to have but not needed. They slow the spindle down after a stop command quicker, esp at the higher speeds, but its something you can live without. As to the value, you'll need more info, guessing could damage the VFD. The value is normally specified in the inverter manual. Typically around 100ohm but too small and you fry the inverter. The wattage rating is typically 10% of the motor rating. See here: Inverter Drive Supermarket | Brake Resistor Calculator (http://www.inverterdrive.com/brake-resistor-calculator.aspx) for more info, scroll to bottom of page and read the info there first before trying the calculator, then decide its a nice to have for now :)

08-10-2012, 07:55 PM
Ok... just looked on CNC 4U site...they say both single and 3 phase input ??? Have to say I've never come across an inverter that does both in the same box, normally you have to specifiy one or other model. Just downloading the manual....

08-10-2012, 07:58 PM
This inverter will just rectify the 3-phase input, so you're fine to pick two of the R,S,T pins and connect the single phase supply to those.

Web Goblin
08-10-2012, 07:59 PM
It looks like the huaqyang vfd. If it is then input mains to R and T. Connect motor to U, V an W and as irving says reverse any two of U, V or W if the spindle runs in the wrong direction. Braking resistor not needed. Look inside the socket on top of the spindle motor, are the connections numbered inside? If not then again check what you have done with a meter to ensure you have the three ends of the motor windings.
Before running it make sure that you have setup the parameters as stated in the manual. If I remember correctly it was very important to set these up before first running the spindle to prevent damage to it.

Web Goblin
08-10-2012, 08:02 PM
Have alook at this to see if its the same as yours.


08-10-2012, 08:05 PM
Yep, Manual say any two of RST... and nothing about braking resistor value... but you wouldnt want one anyway...

08-10-2012, 08:34 PM
Thanks for the fast replies!

I certianly don't want a 220watt resistor, that would be crazy big and expensive.

WebGoblin, that image appears to be the same as mine. It is Huangyang HY02D223B.

08-10-2012, 08:36 PM
If I remember correctly it was very important to set these up before first running the spindle to prevent damage to it.

Can you suggest what settings and values I need to use? I've read it is not good to power up the VFD without the spindle connected so it would be nice to know roughly what settings to go for in advance.

Web Goblin
08-10-2012, 08:42 PM
This is basically the email I got for setting mine up.

1st set PD013 to 8
2nd set PD005 to 400
3rd set PD004 to 400
4th set PD003 to 400
5th set PD144 to 3000

Check all settings are correct except for PD013. This is the factory reset and checking this will reset all the others so make sure you set PD0013 first and dont check it again but do check the others are correct.

10-10-2012, 08:44 PM
Thanks guys, I got it working :) How do I know the actual RPM speed though, rather than the frequency?

A little video of first cuts here - DSCF8196.mp4 video by tenson_uk - Photobucket (http://s608.photobucket.com/albums/tt169/tenson_uk/?action=view&current=DSCF8196.mp4)

10-10-2012, 11:52 PM
Good to see you got it going. Looks to be going at a respectable speed too.
I spy a ring hanging on the left ballscrew, so either it just got married or a locknut has fallen off? It looks like you'll have to put some threadlock on them if tightening the two nuts against each other isn't working.

If you press the sideways arrow (<<) key on the VFD it will scroll through various different useful readouts, including rpm. I tend to leave mine showing current since that's a good indicator of if the cutter is operating normally.

Also, if you haven't already, check that PD141,PD142 and PD143 are set correctly - these are the motor voltage (220), rated current (8) and number of poles (2) respectively. In addition if you want to save a couple of seconds waiting for the spindle to get up to speed and stop you can adjust PD14 and PD15 which are the ramp-up and ramp-down times. You should be able to set both to a couple of seconds safely, but don't go too low as it will draw too much current and needlessly stress the system.

11-10-2012, 12:19 AM
Good eyes Jonathan, I hadn't noticed it came off!

I had set PD141 to 240V since I thought that was meant to be the over-voltage protection for the mains. I'm better to keep it at 220V, then?

I'll have to play with the VFD a bit more, the manual was hard to decipher.

Thanks again, I'll maybe post some videos again when I do more cutting.

11-10-2012, 12:31 AM
I had set PD141 to 240V since I thought that was meant to be the over-voltage protection for the mains. I'm better to keep it at 220V, then?

It says in the manual that PD141 is the 'Rated Motor Voltage' and to set it 'according to motor nameplate' and my 2.2kW spindle has 220V written on it so that's what I went with. It's not going to make a great deal of difference to be honest.