# HY VFD (Isacon not Huanyang) external pot speed control



## bollie7 (Oct 29, 2019)

Gday Everyone. 
I have one of these Isacon HY series VFD's (Like a lot of people I bought it thinking it was a Huan Yang. Luckily for me I only paid $125 AUD for the VFD plus a 1.5 Kw 3 ph motor - both unused).
So, I have mounted the new motor to my lathe and wired the VFD. It runs the motor quite well from the panel (which doesn't not have a potentiometer on it. ) but its got me beat as to getting it to run with an external pot for frequency (speed) control. 
There are lots of copies of the user manual on the net but I've yet to find anything about running one from an external pot.
The diagram in the book shows a "1-5k" pot. So I have a 5k pot wired in as per the diagram. I have changed the settings (Pno3 -"Source of runtime frequency" to 1 for potentiometer but it doesn't work.
So has anyone else with one of these, wired up and gotten working, an external pot?
Any advice would be greatly appreciated.
Atm I don't have any scans of the manual with me that I can post up.
meanwhile if I have any success I'll post up the results here
thanks in advance

Peter


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## Bob Korves (Oct 29, 2019)

My VFD is an Askpower A131, different brand, but I also had similar troubles with the wiring diagram that came with it.  The diagram was poorly laid out, which make it confusing.  First, it has separate parts of the wiring diagram for controlling three phase or single phase power.  Make sure you are looking at the correct one for what you are doing.  Also, the motor ground and the controls ground are completely separate, and you must ground the pot to the controls ground.  Hope that helps, your VFD may be different than mine, but maybe they have a different protocol for doing wiring diagrams in China, and perhaps yours is similar to mine.  You should only use the center lug of the pot for supply, and just one of the outside two for return to ground, switch terminals if high/low for your application is working backwards.  You only need those 2 wires for a single phase potentiometer hookup used for low voltage control applications.


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## mksj (Oct 29, 2019)

Try setting Pn03 to 3 external 0-5V signal, sometimes the default of 1 is the internal (panel mount if present) potentiometer. An external potentiometer is wired between the GND (0V) and 5V OUT terminals with the sweep connected to 5V IN. Make sure you are using the GND (7) and not the chassis ground. I normally will not deal with these inverters.


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## bollie7 (Oct 29, 2019)

Bob Korves said:


> My VFD is an Askpower A131, different brand, but I also had similar troubles with the wiring diagram that came with it.  The diagram was poorly laid out, which make it confusing.  First, it has separate parts of the wiring diagram for controlling three phase or single phase power.  Make sure you are looking at the correct one for what you are doing.  Also, the motor ground and the controls ground are completely separate, and you must ground the pot to the controls ground.  Hope that helps, your VFD may be different than mine, but maybe they have a different protocol for doing wiring diagrams in China, and perhaps yours is similar to mine.  You should only use the center lug of the pot for supply, and just one of the outside two for return to ground, switch terminals if high/low for your application is working backwards.  You only need those 2 wires for a single phase potentiometer hookup used for low voltage control applications.


Thanks for your fast reply. I'll have another play tonight.
peter


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## bollie7 (Oct 29, 2019)

mksj said:


> Try setting Pn03 to 3 external 0-5V signal, sometimes the default of 1 is the internal (panel mount if present) potentiometer. An external potentiometer is wired between the GND (0V) and 5V OUT terminals with the sweep connected to 5V IN. Make sure you are using the GND (7) and not the chassis ground. I normally will not deal with these inverters.


Thanks for the info. Funnily enough I was thinking about this a short time ago and thought that maybe the setting for the pot was as you said. 
I didn't realise that this VFD was not a HuanYang until after I bought it. Still, for $125 aud for the motor and vfd it was a good buy I thought. A new 1.5Kw motor is around $180 -$220 for a cheapie here in Aus.
I have a Huan Yang on my mill and I'm very happy with it.
Peter


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## bollie7 (Nov 1, 2019)

That did the trick, 5K pot wired as mksj suggested above. With the pot on its own I found that when wound back, the VFD stopped. A couple of members on another forum suggested I use a 1k resistor on the low side of the pot. I did this and that has solved that problem.
Now i just have to make up the permanent control box.
peter


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## mksj (Nov 1, 2019)

You set the range of the speed of the VFD by setting the maximum run-time frequency (Pn 10) and  minimum run-time frequency (Pn 11) in Hz. Most VFDs have internal program scaling specific to the speed pot so it sets the starting/ending and slope relative to the analogue inpput voltage of the speed pot and for some also the speed direction. What you have done with a 1K resistor in the 0V/Gnd leg basically starts the speed pot at ~0.8V instead of 0V. There can be a problem in with some VFDs if yo say set the lower bound to something like 15 or 20Hz and under some circumstances  (like hitting the JOG)  it will want to instantly adjust to the lowest frequency and this will trip an over current fault. I usually set the VFD lower bound of the speed setting to the JOG frequency but this varies by VFD model.  I think you are fine as is. You still should check Pn 10 and PN 11, I would suggest something like 60 and 6 Hz assuming you have a 4P motor with a base speed of 50Hz (Australia).


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## bollie7 (Nov 4, 2019)

mksj said:


> You set the range of the speed of the VFD by setting the maximum run-time frequency (Pn 10) and  minimum run-time frequency (Pn 11) in Hz. Most VFDs have internal program scaling specific to the speed pot so it sets the starting/ending and slope relative to the analogue inpput voltage of the speed pot and for some also the speed direction. What you have done with a 1K resistor in the 0V/Gnd leg basically starts the speed pot at ~0.8V instead of 0V. There can be a problem in with some VFDs if yo say set the lower bound to something like 15 or 20Hz and under some circumstances  (like hitting the JOG)  it will want to instantly adjust to the lowest frequency and this will trip an over current fault. I usually set the VFD lower bound of the speed setting to the JOG frequency but this varies by VFD model.  I think you are fine as is. You still should check Pn 10 and PN 11, I would suggest something like 60 and 6 Hz assuming you have a 4P motor with a base speed of 50Hz (Australia).



Thanks for the info. I appreciate your input and advice. I will check the settings you have suggested when I have finished wiring up my external control panel.
peter


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## bollie7 (Nov 9, 2019)

I've got my external control panel wired up, fitted and running.




Since I made the video I've also set up the tacho. Unfortunately it's not working very well atm. The indicated speed fluctuates wildly even though the spindle is at a constant speed. I've tried 3 different power supplies with the same result. I just read on an Amazon review that the polarity of the magnet is important so tomorrow I'll look at that.
Peter


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## mksj (Nov 9, 2019)

All the hall sensors for these tachs are polarity specific so you must have the N pole of the magnet facing the sensor otherwise you will get random readings. The type of Hall sensor is typically a normally open (NO, NPN type, NJK-5002C) they usually have a small LED light in the end that should turn on when the magnet is facing the sensor in the correct orientation. The most common problem is people have the wrong magnet orientation, the sensor is faulty (needs to be replaced) and less common the sensor cable is either grounded to the machine (if shielded) or near the motor cable and is picking up the VFD electrical noise. I always check the magnetic orientation before installing it, power up the tach. and swing the magnet in front of the sensor. In one orientation the light will come on consistently when the magnet is swung within .1-.2" of the sensor.



The other problem I see with your install is that you are running the VFD signal control cable tied to the motor cable. This is an absolute no, no, as the motor cable will induce electrical noise and false signaling into the control cable. Doesn't matter if it is shielded, don't do it. This is one of the most common problems in false signaling and communication errors when people run low voltage communications wires with AC lines, in particular with VFDs. You need to have a minimum of at least 4" between the cables, communication cables if shielded are only grounded at the source end (VFD), shielded motor cables the shield and ground are attached at both ends. Always be sure to cover/insulate the shield wire and any exposed shield so it cannot short to anything.


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## bollie7 (Nov 10, 2019)

MKSJ. Thank you very much for all the info in your last post. Very informative. More good info in one post than I have seen for some time. Greatly appreciated. The first time I have seen a decent description of how the hall sensor and magnet work together. 
regards peter


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