# Pot and switch types for remote VFD



## Ropata (Dec 5, 2017)

Hi Guys,

I want to wire in some on and off push buttons and speed control pot to this cheap 2hp VFD I am about to hook up to my new belt grinder. I just want the unit away from the dust and have a smaller better looking panel to control from. Can anyone please give me some advice about what rating and size etc for the pot and buttons?


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## gr8legs (Dec 5, 2017)

Most VFD control circuits are low-voltage low-current and any switch will work fine.

The potentiometer resistance value you get depends somewhat on the input resistance of the VFD control, which is usually in the specifications. A general rule is the pot resistance should be 1/10 of the input resistance of the circuit so it appears as a voltage source to the VFD input port. Typically the input resistance of the VFD is 10K ohms, so a 1K or so pot would be appropriate. Check the VFD specs and purchase accordingly.

The power rating of the potentiometer is an Ohm's law calculation: Power=Voltage squared divided by resistance. That calculates the actual power dissipated by the device, prudence dictates getting a pot rated at least twice the power dissipated as a safety factor.

Have fun!

Stu

Uh oh - seems I have double posted and cannot figure out a way to delete the doppelganger. Editing, no problem. Deletion? I can't find that button!


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## Ropata (Dec 5, 2017)

Thanks Stu. I can't  seem to find anything in the badly translated manual. It seems quite a popular model. It's the same one that Banggood have been sending out to Youtubers to test. Here are some photos of the relevent pages I think. Does it look like I need to install jumpers if using a remote pot to you?


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## Karl_T (Dec 5, 2017)

it does look like you jumper 1 and 2 for external rheostat pot.

cannot quite read the value on page two. You could just try a 5K one.

Yep most any small switch will do.


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## CluelessNewB (Dec 5, 2017)

That looks like a Huanyang VFD.   The manual that I have for mine shows a 10K ohm potentiometer.   You will want a* linear taper* potentiometer rather that an  audio (logarithmic) taper.    (All of the Teco VFD's that I have seen also use 10K ohm pots)


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## KMoffett (Dec 5, 2017)

For momentary push buttons, you will have to add relays. Attached is the configuration for my remote. Probably a bit more than you want. I jdidn't have reverse because it was for an auxiliary high spindle that was never going to need reverse.  What functions do you want in the remote?

Ken


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## CluelessNewB (Dec 5, 2017)

If it's like my Huanyang VFD it supports "3 wire control".  I assume for a grinder you don't need reverse.  Two momentary buttons should work, a RUN button that is NO (normally open) and a STOP button NC (normally closed).  No relays are required for this VFD.  The controls are low current/low voltage so electrically just about anything will work.  You may want to look for something that is mechanically strong and sealed well for dust. If you don't need reverse the NO (normally open) button connected to D2 in the diagram below is not required.


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## Robert LaLonde (Dec 5, 2017)

CluelessNewB said:


> I assume for a grinder you don't need reverse.  Two momentary buttons should work, a RUN button that is NO (normally open) and a STOP button NC (normally closed).  No relays are required for this VFD.  The controls are low current/low voltage so electrically just about anything will work.  You may want to look for something that is mechanically strong and sealed well for dust. If you don't need reverse the NO (normally open) button connected to D2 in the diagram below is not required.


  Most belts are directional, but I have seen some belt grinders built to be reversible.  I guess you can always flip the belt around.


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## Bob Korves (Dec 5, 2017)

Ropata said:


> Hi Guys,
> 
> I want to wire in some on and off push buttons and speed control pot to this cheap 2hp VFD I am about to hook up to my new belt grinder. I just want the unit away from the dust and have a smaller better looking panel to control from. Can anyone please give me some advice about what rating and size etc for the pot and buttons?
> View attachment 248979
> View attachment 248980


On my B&S surface grinder, I installed the same basic VFD as you are using, only 2.2KW (3 HP) and without the potentiometer.  Only $10 more on eBay than the 2 HP version.  I installed the VFD in a project box after cutting round holes in the top and bottom for a muffin fan (top) and filters (top and bottom).  The fan has a sheet of thin polyethylene on the top to also help keep grit out.  The poly bends upward when the fan is running, and settles back down when the fan stops..  I removed the front covers of the VFD completely, and then removed the display/control panel from the front cover.  I mounted the display/control unit to the front of the enclosure and added an oak frame for looks.  The wiring tape from the VFD to the display reaches easily.  There are also remote controls for spindle speed and spindle on/off installed in the front cover of the project box.  They are programmed to control the VFD.  Since I got this finished, I have never touched the buttons on the VFD control/display, which are known for being less than robust, and will only use them if and when I need to reprogram something.  The added switch and pot are cheap and easy to replace if needed, and AFAIK spare parts are not available for the cheap Chinese VFDs.  The remote controls are also a lot nicer and more convenient to use.  It works good.


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## Ulma Doctor (Dec 5, 2017)

Hi Ropata,
you are going to need maintained contact or latching switches for the VFD you have chosen.
i installed the same type of VFD on my shenwai sw 900b, but mine is the 2.2Kw (3hp) version
a 10K potentiometer will work fine.
as far as switch rating is concerned, the voltage and amps are low when you use the DCM power
24volt/ 5 amp rating would be more than sufficient for the switches


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## Bob Korves (Dec 5, 2017)

Ulma Doctor said:


> Hi Ropata,
> you are going to need maintained contact or latching switches for the VFD you have chosen.
> i installed the same type of VFD on my shenwai sw 900b, but mine is the 2.2Kw (3hp) version
> a 10K potentiometer will work fine.
> ...


Yes, Mike.  At first I misinterpreted the poor installation manual drawings, understanding the wiring diagram to require momentary switches.  Turned out that was wrong...  Maintained contact (on/off, like a house lighting wall switch) or latching (for power outage safety) switches are needed.


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## Ropata (Dec 5, 2017)

Ulma Doctor said:


> Hi Ropata,
> you are going to need maintained contact or latching switches for the VFD you have chosen.
> i installed the same type of VFD on my shenwai sw 900b, but mine is the 2.2Kw (3hp) version
> a 10K potentiometer will work fine.
> ...


Thanks Ulma. And am I correct to have to install the jumper on the J1 connectors?


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## Ulma Doctor (Dec 5, 2017)

yes sir, 1&2 are "jumped"  when you install the external pot


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## Ropata (Dec 5, 2017)

Ulma Doctor said:


> yes sir, 1&2 are "jumped"  when you install the external pot


Awesome, Thanks for everyone's help.


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## CluelessNewB (Dec 5, 2017)

If it's like my Huanyang you may use momentary switches but maintained switches will also work.


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## KMoffett (Dec 6, 2017)

If you want:
Speed control...Pot
Forward-Reverse...Toggle or Rotary Switch
Start... Mom Push button
Stop... Mom Push button
The DPDT toggle shown shown has a center-off position so switching between forward and reverse shuts off the drive, and requires pressing Start again.
Different manuals vary in whether the VFD has +12VCD or +24VDC to power the remote relay.

K2n


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## Cadillac STS (Dec 6, 2017)

*For the 10k pot get a 10 turn pot*. Takes 10 turns from 0 to 10k. That way you get better smoother control of your speed.


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## CluelessNewB (Dec 6, 2017)

I don't understand why you would want to complicate it by using a relay.  This VFD out of the box is designed to use 3 wire control just like a typical motor starter which consists of a Normally Open Momentary "Start" Button and a Normally Closed Momentary "Stop" button.  There are some VFD's that do not directly support 3 wire control, the Teco FM50 for example but this is not one of them.   The diagram above in post #8 is from page 37 of the owners manual that I have.  It is exactly how my Powermatic 30 belt sander is hooked up (except I didn't bother with the reverse button connected to D2).  It has a momentary buttons as listed above.  The one I have is a 2.2kw Type - HY02D223B


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## KMoffett (Dec 6, 2017)

Even though the manual for my Huanyang shows the D1/D2/D3 Fwd/Rev/Stop schematic with momentary push buttons,  it didn't work that way in the actual controller. Also the +24VDC output was available in my controller, but not in the manual.  I have at least 4 different manuals, purported to cover the same controller, but with different control terminals.

Ken


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## Ropata (Dec 25, 2017)

Finally got a chance to try setting it up properly and the bugger won't do momentary switches, looks like I need latching switches. Also wondering how to get the speed spread over the whole turn of the 10k pot I have, I get to full speed in the fist quarter turn?


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## Cadillac STS (Dec 25, 2017)

Ropata said:


> Finally got a chance to try setting it up properly and the bugger won't do momentary switches, looks like I need latching switches. Also wondering how to get the speed spread over the whole turn of the 10k pot I have, I get to full speed in the fist quarter turn?



Look into the documentation to see what that particular controller needs.  Maybe try a 5K or 2.5K pot for full range.  Once the resistance is figured out it is better to have a multi turn pot like 10 turns to dial in the speed with more control.

If you are sure you get 100% speed just turn the pot to that setting and check the resistance with an ohm meter to give you the value.


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## KMoffett (Dec 26, 2017)

The pot is a voltage divider. Whether it's 1K or 10K makes no difference...except the load it places on the 10V source.  At half rotation it will supply 5v to the Analog input VI.  Check program setting PD070. This sets the range for the Analog input.  If it's "0", a 0 to 10V input gives you the full speed range. If it's "1" a 0 to 5V input will give you the full range. If you are getting the full speed at half rotation I will bet that it's set to "1". Attached is a settings list from a manual.  I'm not sure what accuracy you need for speed settings, but a ten-turn pot seems like a lot of knob turning overkill. 

Ken


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## CluelessNewB (Dec 26, 2017)

There are two common types of potentiometers linear taper (what you want) and logarithmic (also called audio) taper.   You want a linear taper, behavior like you describe would be caused by a logarithmic taper.    Also check that you have the correct pins on the potentiometer hooked to the proper terminals and double check that the connections are good.  The Huanyang VFD's have particularly cheaped out connections.


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## Ropata (Dec 26, 2017)

CluelessNewB said:


> There are two common types of potentiometers linear taper (what you want) and logarithmic (also called audio) taper.   You want a linear taper, behavior like you describe would be caused by a logarithmic taper.    Also check that you have the correct pins on the potentiometer hooked to the proper terminals and double check that the connections are good.  The Huanyang VFD's have particularly cheaped out connections.


I have a 10k three pin linear pot.


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## Ropata (Dec 26, 2017)

So From what I read in other places for three wire on/off switching, the on switch needs to be  normally open and the off switch normally closed. I have tried this and I would have to hold the on button on for it to run. Am I missing a setting?


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## Ropata (Dec 26, 2017)

KMoffett said:


> The pot is a voltage divider. Whether it's 1K or 10K makes no difference...except the load it places on the 10V source.  At half rotation it will supply 5v to the Analog input VI.  Check program setting PD070. This sets the range for the Analog input.  If it's "0", a 0 to 10V input gives you the full speed range. If it's "1" a 0 to 5V input will give you the full range. If you are getting the full speed at half rotation I will bet that it's set to "1". Attached is a settings list from a manual.  I'm not sure what accuracy you need for speed settings, but a ten-turn pot seems like a lot of knob turning overkill.
> 
> Ken
> View attachment 250978


Yes, a 10 turn pot is not what I need. I tried setting pd70 to 1 and 0 and the difference is minimal, I have to turn it about one more number to get full speed when pd70 is set to 1.


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## Ropata (Dec 26, 2017)

Ropata said:


> Yes, a 10 turn pot is not what I need. I tried setting pd70 to 1 and 0 and the difference is minimal, I have to turn it about one more number to get full speed when pd70 is set to 1.


I just tried pd70 on number 4 setting and it now gets to full speed halfway around the dial so I'll live with that for now.


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## 4GSR (Dec 27, 2017)

CluelessNewB,

The parameters pd071 thru pd076, how would these affect the operation of the 10K pot? I have a similar situation I'm dealing with.  I've bought a NOS RatShack 10K pot I was going to try, about double the size of the one I'm currently using.  The RatShack one is linear and the current one I'm using is supposed to be linear, but it acts exactly like the one Ropata is using.  Not trying to hijack the thread, just trying to get additional information that may help both of us here.  Ken

Oh, I forgot to mention, I have a similar VFD here too.


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## ttabbal (Dec 27, 2017)

You can verify if they are linear easily. Connect an ohm meter to the center and one of the outside legs. Slowly turn the pot and watch the readings. 

Can't help much with the VFD part as my first one isn't here yet.


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## KMoffett (Dec 27, 2017)

Attached are Huanang default codes from a manual. I have several manuals, but these seem consistent. Also, is a PDF of an Excel file of the codes I have in my VFD. Some are the factory set, others are mine.  As I remember I spent a lot of time searching the forums to see what others have used.
For a lot of the default settings of 50Hz, I used 400Hz, like PD003, PD004, PD005, and PD072.  If anyone has a disagreement with this, I'm open. But these have worked so far.

Ken

More than you want:
Here are a lot of posts that I had looked at: https://en.industryarena.com/forum/huanyang-chinese-vfd-settings-manual-here--117782.html
Also Google: Huanyaun VFD programming codes


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## CluelessNewB (Dec 27, 2017)

4gsr said:


> The parameters pd071 thru pd076, how would these affect the operation of the 10K pot?



PD071 Analog Filtering Constant:

This is probably just fine set at the default of 20 or higher.   This will control how fast the VFD responds to changes of the analog control signal,  this not really an issue with manual controls but might be if an external sensor was used. 

PD072 Higher Analog Frequency:

  PD072 will limit the maximum speed your motor will go.  It's a frequency so if your motor is normally rated at 60 cycles per second and runs at        3600 rpm and that is the maximum speed you wan to run it this should be set to "60.00".    If you wanted to run it at 5400 rpm (1.5 x3600) you    would set PD072 to "90.00"  (1.5x60)

PD073 Lower Analog Frequency:

  PD073 will limit the minimum speed your motor will go.   You can leave this at the default 0

PD074 - PD076 I would leave these at the default 0

  Truthfully I can make a semi-educated guess at what they do but the manual is severely lacking in a good description.


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## KMoffett (Dec 27, 2017)

CluelessNewB said:


> PD071 Analog Filtering Constant:
> 
> This is probably just fine set at the default of 20 or higher.   This will control how fast the VFD responds to changes of the analog control signal,  this not really an issue with manual controls but might be if an external sensor was used.
> 
> ...





To add to CluelessNewB's information (thanks!), my spindle runs at a maximum of 24,000 RPM, so 400 is my choice (60x400=24000) for PD072.

Ken


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## 4GSR (Dec 27, 2017)

CluelessNewB said:


> PD071 Analog Filtering Constant:
> 
> This is probably just fine set at the default of 20 or higher.   This will control how fast the VFD responds to changes of the analog control signal,  this not really an issue with manual controls but might be if an external sensor was used.
> 
> ...



Excellent explanation!  Thank you.


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