Member postings for James Walker

Based on the description in my manual I figured that was probably what is was. Did some tests which proved my interpretation correct.

@Robert G - On my mill the turret moor is is a Dahlander motor which means it is dual speed without having two windings. Anyway I leveraged those two full speed ranges with the VFD by adding a mechanical switch to switch the winding connections. It means I can leverage a lower speed while keeping the VFD stresses down on the old motor.

This is possible with the AT4 as it is a simple Voltage/Hz style VFD which are able to run multiple motors of the same type at once. As compared to a Vector VFD which is tuned to the specific motor parameters. And when you switch poles those parameters change.

There is one rule you need to live by so you dont blow your VFD, NEVER CHANGE THE POLES WHEN THE VFD IS DRIVIG THE MOTOR. The motor must be stationary and the VFD idle.

cheers - James.

Graham - I have a larger mill, nearly Bridgeport sized so the 66mm version is of keen interest. Has it been published yet? If so where?

regards - James.

Thanks for the suggestion. I do hope they solve the proper reader. I detest pocketmags.

To add to this with a more fundamental issue. The last digital MEW available is Feb. We are now up to June. While I am looking forward to the binge read it would be nice to have access to the recent mags my sub has paid for.

If there is some browser trickery needed to make the more recent issues visible then I would love to know it.

regards - James.

I always took P00 as being the max V that the unit could output. The reason being that P02 and P04 have a cap of either 220V or 380V which I believe is determined by P00. Anyway I have my P00 set at 380V and it is fed a 220-230V supply.

Also if you have settings that you cannot change you need to input the default "0" password into P09. i.e. jusrt go into param update mode, go to input mode on P09 and "set" the value to 0. This should unlock everything. Did for me.

Cheers,

James.

This is a good point. I used 60Hz as my motors talk to a 50 and 60Hz rating (P01). This meant I could get full speed out of the motors and increase versatility. You can set max Hz (P06) higher than P01). However I believe the curve flat-lines after you exceed the reference set in P01. So while the frequency and thus speed of the motor will increase you do not also get the voltage increasing. It is all a balancing act.

This is also a useful bit of info. These graphs show different torque curves based on how you set the mix of min/intermediate/max voltage and frequency. Max frequency on the graph is reference off P01 wit the others being P02 to P07.

In case it is useful here are the values I am running on the key settings. Note - I did a factory reset of values so I will note only things that are different to the defaults per the VERY small manual. I also adjusted for a higher voltage curve to get the response I wanted out of my motors.

P01=60

P02=45

P03=2.5

P04=20

P06=60

P07=15 (this is per recommendations I have found as these style VFDs do perform poorloy under 15Hz)

P10=2

P11=2

P20=60

P21=1420

P22=6 (this setting impacts the sinnging sound of the motor. The higher the setting the quieter it is as it goes out of juman hearing. However higher frequency is harder on insulation. So on old motors lower is safer, balanced with noise/annoyance factor)

I have factory defaults on P65 and on. This includes the settings for the external pot. But to explicit here are those values.

P73=31440

P74=2096

P75=1130

P76=9500

Martin - did you determine what P67 does? It is marked as "Voltage coefficient" in the manual.

Gents I have 2 of these VFDs commissioned on a Dah Lih mill. They run the Vertical, Horizontal and Power Feed motors. All motors are 380/400V 3ph. They are wired up to expect that range.

As noted this model VFD converts 220-240V 1PH in and spits out 380V/3PH.

The control pot I use is 10K. It is wired per the manuals instructions. I used Parameters P73 and P74 as noted by Bruce to adjust to get the response I wanted from the 10K pot.

I am happy to check and post the parameters I have set for all the key values if that is of interest and would be helpful.

I know when I did my install the level of info on this control as a bit like getting blood from a stone. So after lots of experimenting I solved most things and have it operating.

Cheers,

James.