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  1. #76
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by Techo1 View Post
    Has anyone successfully set up an external potentiometer on one of these? I have set the parameters that I think are applicable and also re-positioned one of the jumpers and it is working but there is a dead spot at the lower end of the pot.
    Do you mean the motor doesn't turn at the lowest frequencies? It depend on the machine/motor but some gear needs at least a few Hz to get them started. My lathes have vector drive VFDs and will keep turning down as low as 0.8Hz but my grinders on a Non-Vector drive VFD need 3.5Hz to run. If a machine has significant inertia or load like a gear box to turn the starting frequency could be even higher. This will appear as a dead pole on a pot.

  2. #77
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    I should have explained the problem in more detail in my original query, the drive is set up with 25Hz as minimum frequency and 75 as maximum and the potentiometer can control the motor anywhere within that range, but everything happens in the last half of the pots travel, the first part of its movement does not alter the frequency until I get to approximately the middle of its range. I hope this makes a bit more sense.

  3. #78
    BobL is offline Member: Blue and white apron brigade
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    It depends on the vfd but some donít auto map the pot min (ie 0) to the min freq but leave it at zero Hz so I your case 0 - 25 Hz will show up as a flat spot on the pot.

    What sort of machine is it?

  4. #79
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    I think that is probably what is happening Bob and that is why I will have to try mucking around with the Analog Lower Input settings using a bit of trial and error as no information is available in the Instruction Manual.

    Edit: This motor is on a Honing Machine.

  5. #80
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    Quote Originally Posted by Techo1 View Post
    Thanks John, the pot that I am using is 5K linear and checks out OK with a DMM, I did originally have a 10K in the machine but I changed to this one because I though that the resistance may have been too high and causing the problem I was having, the manual does not specify the type of pot to use. I have used 10K pots on all of my other VFD setups without any similar issues.

    I am using the analog input 1 (A/1) terminal for this and there are 2 parameters relating to the lower limit that I think may have to be set for the specific application, they are P2.02 Lower A/1 limit 0.00 V~10.0V and P2.03 Corresponding setting of lower A/1 limit -100.0~100.0%, the only problem is that I don't know what to set them to or even if it will help with this problem.
    Hi Lex,

    I don't know enough about parameter settings to help ! But unless its a typo "-100%" seems wrong. I would have thought "0~100%". Since the pot checks out, the only other thing must be settings.
    Best Regards:
    Baron J.

  6. #81
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    I agree John, but that is exactly as it is written, it doesn't mean that it is right and exactly what it means I have no idea. There's plenty of typos and other blatant mistakes in the manual.

  7. #82
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    It was a simple fix in the end, just by setting up the Analog Input Limits correctly: High Limit 10V = 100% = 75Hz Low Limit 0V = 33.3% = 25Hz.
    Now I have to work on getting the cheap Chinese panel mount tacho to respond faster to the speed changes, at the moment it can't keep up and can take a second or two to show the correct RPM after moving the dial on the potentiometer.

    Attachment 393586

  8. #83
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    Hi Lex,

    Were the new percentages the ones that were -+100% ?

    Your attachment is not attached !
    Best Regards:
    Baron J.

  9. #84
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    Yes John, although I don't think you can actually set a negative percentage, I will try it later.

    I struggled to get the video attached and I thought that it was OK because it works for me but obviously not for anyone else, I will try to fix it up.

  10. #85
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    My first attempt at posting this video failed miserably, I hope it works this time.
    The video shows that the pot is now working over it's full range, it also shows that the digital tacho is very slow to respond to the speed changes, I tried it with a different type of sensor without any success.



  11. #86
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by Techo1 View Post
    My first attempt at posting this video failed miserably, I hope it works this time.
    The video shows that the pot is now working over it's full range, it also shows that the digital tacho is very slow to respond to the speed changes, I tried it with a different type of sensor without any success.
    I think it's a sampling problem in that the tacho circuit has to count a certain number of pulses before it determine the rpms. You can check if that is the case by doubling or tripling the number of magnets - of course you will have to halve of divide the output by 3 accordingly. The Tacho on my WW lathe seems to have faster response than the one on my MW lathe which i similar to yours, but they are both the same basic cheap Ebay taco.

  12. #87
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    Hi Guys,

    Yes I concur with Bob ! The shaft has to rotate at least twice in order to get a speed. So a larger diameter will take longer to get a reading.

    This is why you often find that the sensor has several magnets or holes whatever it uses.
    Best Regards:
    Baron J.

  13. #88
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    The other machines that I have set up with this type of tachometer use 6 or 8 pulses per revolution and were configurable for PPR counts of 1 to 9999 but I could not find one this time and had to settle for this one, it does not have the switches to set divider values so I think I am stuck with one PPR.

  14. #89
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    Default ecogoo 1 ph.220v to 3 ph inverter - experiences

    Quote Originally Posted by .RC. View Post
    I ordered a 4KW version to power the motor generator on my 10EE. It might get some use if I can run it off 240V.
    I have been stuffing around for some months trying to get my 4kw air compressor to run/start with my phase changer 6 after the electricity supplier reduced the available street voltage - this is well documented on MW forum under 'unusable compressor' -recently I had an industrial electrician try to determine what is at fault and after phone hookup with phase changer they determined I have a quite old phase changer and they are currently updating the internal electrics to the latest spec. but say only 50/50 it will solve my problem-when speaking to my sparkie about this I said I guess I will have to buy a 3ph. generator and he said 'not so' I only need to buy a single ph. to3 ph. inverter (less than $1000) so I am very interested in how you get on with your purchase , please let me know, however, the startup torque on my compressor I believe is 84A which is probably more than your 10EE
    stay safe

  15. #90
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    I am only starting a motor generator that runs the 10EE, I currently run it off a plain old power board that has it's own overload reset button on it so even when starting the MG unit it only draws about 5 amps @ 250V total. (Our voltage here runs around 250V as we are close to a voltage booster)

    I do not think a VFD is going to help you with your compressor. I put it down to either upon startup of the motor your line voltage is going too low and clicking out the phase converter. However I had a lathe with a 10hp motor, I have a phase changer 8 and it could start that motor direct online from dead to 1600rpm with a 10" chuck on the lathe. The line voltage would drop quite a lot to under 200V when doing it. My phase converter at the time I bought it in around 2009 the board was an obsolete design (I got it at a quite reduced price). I have since had the control board updated after I blew two boards up (one from lightning and the other from the old design burning a trace out) but it made no difference to the capabilities of the converter.

    Otherwise the capacitors to take a flogging and might be getting old as I have had to replace three or four. I have also had issues with the connections onto the capacitors. But it has been a solid unit.
    Gold, the colour of choice for the discerning person.

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