[firstyear]

Hey guys

I've all but finished my very first cnc build but...

Im tring to work out how to wire up a Commander SK VFD for 220v single phase input and was hoping that someone could help point me in the right direction to get my spindle spindlizing...

The model number is SKCD200220 (it's 1+3 phase)

so far I've worked out;

mains+ goes to VFD L1
mains- goes to VFD L3/N (for 220v single phase)

Where does mains ground go? or not?? Sorry if this is a stupid question.

I'd also love to learn how to hook it up to mach3 if anyones done that before? I have a dmm-tech DMB4250-8B break out board



thanks for tyour help
firstyear :wee:

[Al_The_Man]

It doesn't make any sense to me that they show a ground connection (ground symbol) as well as a PE Service ground connection and a motor frame ground, they should all be the same?
OK I see a link over from one to the other, so that makes sense now.
Al.

[firstyear]

Hi Al thanks for the reply - That had/has me stumped too.

the "ground symbol" goes to the motor so Im guessing that one's ruled out?
Which leaves 2 x PE.

Do you think I should wire it to the '1st' PE which loops to the "ground symbol"?

[Al_The_Man]

They should all be linked and common to each other, I assume the optional ground shown on the motor is a ground stake.
The frame of the motor should go to the service ground connection.
Al.

[firstyear]

thanks again Al - first PE it is then!
i'll try and pick up some screened cable tommorow and wire it up - fingers crossed ha!

[Jon Atkinson]

Hi,

Page 7 of the DMB4250 User manual looks to be a good reference.
I'm assuming that VFD spindle drive is the Commander SK.

You need to cross reference this with the diagram on the rear cover of the Commander SK getting started guide.

Terminal T3 is the 10V
Terminal T4 is the analog volt input
Terminal T1 is the analog ground (0V)

Terminal B5 is FWD / STOP
Terminal T1 is also the digital ground

Power wiring can be found on page 13 of the getting started guide.
I've got an issue 8 manual.

You then need to follow the quick start commissioning section to set up the drive for the motor - see page 42

This is assuming that the motor is an induction type motor.

Regards
Jon A

[mactec54]

firstyear

Were you have the question mark just make sure that terminal is ground to the chassis/mounting frame of the VFD, if it is then you can use it/them for your input AC ground Check the PE Terminals as well it looks like you can use one of those as well for a ground

[mactec54]

firstyear

The first thing you want to do once you have it wired, is put all your motor parameters in, then you will be able to test run the spindle before you, wire to the breakout board

Attached are the Breakout Board & Mach setup

[firstyear]

Hi Mactec, Jon and Al thanks so much for your help


I just heard back from Craig at Control Techniques America who confirms what we found...

-Connect the mains ground to the first PE terminal, the PEs and earth are all connected together. Use terminals L1 and L3 for your mains input -

I'l try and keep it simple just incase someone else wants to go down this road..



To wire up a Commander SK to mains 220v single phase input:

-for the SKCD200220 use 10mm wire (AWG8) -

Mains + goes to VFD L1
Mains - goes to VFD L3/N
Mains ground/earth goes to the first VFD PE terminal (first from the left)

- Now put all your motor parameters in the VFD, then you will be able to test run the spindle before you wire to the breakout board -

Thanks Mactec, Al and Craig


To Wire a connection from a Dmm-tech DMB4250-8B Breakout board to a Commander SK VFD:

-for the SKCD200220 use 6mm wire (AWG10) -

For the AV_OUT (used for spindle speed)
+Vin goes to VFD Terminal T3
A goes to VFD Terminal T4
G goes to VFD Terminal T1

DOUT_16 (used for VFD on/off or spindle FWD / STOP???)
D16 goes to VFD Terminal B5
S16 goes to VFD Terminal T1

- Now follow the Dmm-tech instructions for setting a VFD/spindle in Mach3 -

Thanks Mactec and Jon


Guys Please let me know if this sounds about right..

[firstyear]

Hi guys in terms of wiring and shielding would you all reccomend that I use;


* 2 core Shielded wire from mains to vfd, using the Shield as the ground/earth connection at both ends? (mains ground to VFD PE)

* 3 core Shielded wire from vfd to spindle, using the Shield as the ground/earth connection at both ends? (VFD ground "ground symbol" to motor ground)

In both cases I would be using the shield as the ground wire... is this ok?



Or should I just wrap the shielded wire ends around my ground wire;

* 3 core Shielded wire from mains to vfd, winding the Shield around the ground/earth connection at both ends? (mains to VFD)

* 4 core Shielded wire from mains to vfd, winding the Shield around the ground/earth connection at the VFD end only? (VFD to spindle motor)


Hope this makes sense??

Thanks
firstyear

[mactec54]

firstyear

No that is not ok to use the shield as a Ground, even though they both go to the same place

You need 3 core plus the shield if you are using shielded cable

You can use flexible conduit that is plastic on the outside & metal on the inside,the metal on the inside if properly installed works just like a shield, but most of the time the right cable can be easier to use

For your AC Input 220v to the VFD the conduit will work well, from the VFD to the spindle motor Cable would be best

[Al_The_Man]

You need 3 core plus the shield if you are using shielded cable

I would have thought 4 wire or 4 core, 3ph and ground?
Saves running a separate ground.

You can use flexible conduit that is plastic on the outside & metal on the inside,the metal on the inside if properly installed works just like a shield

I generally run liquid Seal Metalic Flexible conduit, available from any electrical suppliers, in either 3/8" or 1/2".
Also offers good protection.
Going this route you would use common TEW or MTW single conductor stranded, 3 conductors tightly wound and the ground ran alongside the 3.
Al.

[mactec54]

Al_The_Man

His AC 220V input is single phase, so only needs 3 core plus shield, or he can use the conduit

For the VFD out to his spindle motor He needs 4 core plus shield

[Al_The_Man]

You do not really need shielded conductors into the VFD, it's a bit of overkill.
Most VFD have P.F. correction now and also the input is low impedance to a 3 ph bridge.
Al.

[mactec54]

Al_The_Man

Yes it is very important to have shielded cable for the input of a VFD in a residential setting, your home

It is not needed in a commercial building setting, but in a home it is a must, most of the hobby builders are in there home, so they should be using shielded cable, or the conduit as the shield were ever it is needed

This is one of the things it will affect in a home,If you have an alarm system in your home, it will go off every time you run the VFD, if you don't have shieled cable or a shielded system of some kind on the input, & good grounding in place

A good test is to have a TV near by when you start your spindle motor, you will soon see if you have done a good job of your wiring/shielding or not, it will turn the TV screen into snow shower if you have done a bad job, If it is good the TV screen will not change

As for the cost $10/$12 more I think it is more than worth while,This a whole lot cheaper than having to put a EMC filter in the input as what is recommended by the manufacturer

[Al_The_Man]

I have wired many VFD's over the years, I have 2 such machines at my home also with no problems and have also installed them for friends.
But the thing is, if your are going to shield the supply, how far do you go back? especially if there is a fairly long run from panel to workshop?
How many are going to run shielded cable back to the incoming service?
I suspect there are very few installing shielded cable on the supply, if any.
Al.

[mactec54]

Al_The_Man

By having a shielded cable or using the Flexible Liqidtight Conduit, Both will do the same job, installed correctly (Over Kill No Never)

It does not Eliminate the EMF Only a EMF line Filter can do most of that, what it does is, It keeps any EMF that is present from around the machine area from messing up computers, machine controls Etc that are near by, or the control on that machine

You say you don't have a problem at your workshop with the 2 that you have, You will be running at 100/120HZ, Are you running any CNC controls, computers with these running,within 2' / 5' of the VFD, You also did the wiring, You also know what you are doing when wiring something like this & what to expect if it is not wired correct, I run Filters on most of mine it is the only way to be in compliance

As the Manuals say get a Qualified Person to Install this Device,( How many DO)You have to give everyone that is trying to Install something like this every chance to make it happen, So a little Shield here & there will not hurt anything, It will only help in the end

Most of these users are using 400HZ to run there spindle motors, you can right away see there is a big difference with what the EMF output,would be, than what you would ever be getting or seeing around your VFD's wiring

I have 5 & sometimes 6 VFD's running 12/14 hours a day & all are attached to machines with computer controls of some kind, so everything has to be right or you will get problems from EMF working in a small area

[Al_The_Man]

Most of the VFD's I have used mention the need to use shielded cable from VFD to motor only if the run exceeds 20m.
For the input, in N.A. there is more of an emphasis on low Harmonic Distortion rather than radiated radio frequency noise, which H.D. at the low frequency it is not radiated, but reflected back in to the supply, this is why again with long supply runs, either a inductor can be used at the VFD or other suppression means rather than shielded cable which does nothing to lower harmonic distortion.
This emphasis on harmonics is due to the effect it can have on the supply power factor and supply transmitted interference to other devices.
IOW, on a long supply run the harmonic distortion will exist back to the supply source (transformer) whether shielded or not unless inductor or other method is used.
I just recently attended a symposium by our large Hydro supplier on the effects of poor P.F. caused by such things as VFD's which was gone into at some depth which outlined some of the problems covered above.
As to spindle and noise problems by DIY'ers, I have found it is more question of inadequate grounding and especially bonding procedures that are the cause of most problems.
Al.

[DavidReinhart]

Hi Yall, I am new using Emerson commander sk ,where do i put the analog input 4 to 20 dcv.It looks like +24 gos to T1 and -24 gos????
Thanks

[Al_The_Man]

Hi Yall, I am new using Emerson commander sk ,where do i put the analog input 4 to 20 dcv.It looks like +24 gos to T1 and -24 gos????
Thanks

Do you mean you are using 4-20ma? Where are you getting the control signal from?
From what I see T1 is common T2 is analogue input and T3 is +10 if needed.
Al.