Omron Yaskawa inverter

I've just set up a Yaskawa v1000 inverter with the recommended 2k2 pot for speed control. It doesn't work correctly - over most of the range the frequency remains the same (set at 50Hz), then the last ⅛ of a turn it goes to zero, with almost no possibility of setting it at a particular setting because it is so sensitive over this very tiny range.

There is no mention of whether the pot should be linear or log, so I chose linear. Do I need to change it to a log pot? Or should I put in a 4k7 or a 10k?

Off the top of my head it should be a linear pot. Inverters usually operate with a 0 to 10V input for the command speed which is generated by OV and 10V from the unit connected to each end of a variable resistor with the wiper wired back to the speed demand input. Check you have a linear pot and that you have the wires to the correct places.

regards Martin

Pot as linear is fine. You have not set the upper and lower frequency limits, look in the parameter settings to find for your unit, It also looks like you may well have not set it to respond to external (ie remote potentiometer) control.

Look around page 153 of the manual to show what is (not) happening

Edited By KWIL on 20/09/2017 12:19:16

Presumably you have acquired this second hand? Out of the box they are programmed for 0-10V input to give a linear voltage / speed relationship.

Might be worth resetting to factory defaults in case anything else hidden away has been changed, then starting from scratch. However, most of our applications will be very close to default anyway so it should only take minutes.

Murray

As well as the above checks, it's conceivable that the pot. isn't giving a smooth resistance variation on the rotating contact. Easy to check with a DVM set to resistance scale. Disconnect the pot. first though!

Or check the pot. output voltage

If it not a log pot by mistake or mislabelling, I suggest checking that the pot is wired correctly.

If you have inadvertantly connected that supply voltage to the wiper and one end, and the inverter is seeing the other end of the pot I think you will get the result you describe.

Ian P

Meant to say it should be a linear pot

Edited By Ian Phillips on 20/09/2017 16:18:28

There are often two places where you have to program the maximum speed, you may also need to program the minimum speed and tell it to use the external pot.

the behaviour you have suggests it thinks the pot is a switch at the moment.

Neil

I've just spent a couple of hours trawling through the manual sat in front of the mill, with a soldering iron and a multimeter.

The net result is that the 2k2 pot is now in the bin, having measured various resistances between 0 and 20Meg with no consistency. I have replaced it with the only other one I have, a 4k7, and checked all the relevant parameters I can find. The result is not all that much different to be honest, still very difficult to set lower motor speeds though better than before. I have programmed a minimum frequency of 12.5Hz, which makes things easier, but I can really only control it accurately from 50 down to 40 Hz, beyond that is just pot luck.

For anyone interested, the pot is connected to +v, A1 and AC (with the centre terminal to A1). The relevant parameters are

B1-01=1, B1-02=1, B1-04=0, H3-02=0, also the min and max frequency settings I mentioned above.

There may be other parameters that are relevant but I haven't been able to decipher them.

Anyone complaining about the HuanYang inverter manual needs to read the Omron one - it is bordering on the incomprehensible.

Never mind Steve, I'm sure that with a little of your "pot luck" you'll soon have it sorted.

Rik

You saw what I did there..

I have a Yaskawa V1000 for my lathe and it took a while to set up. The manual isn't great... but not bad.

I don't remember anything at the top of my head right now... except that the 2K pot recommended by Yaskawa didn't work right. It was basically "dead" for about the first 1/4 of each end, only changing in about half of its rotation. I changed to the most common 5K pot and it solved the problem (there is a very slight dead zone still but so small I don't even notice it unless I try to).

I can try to look up the connections and parameters. From memory the Yaskawa was actually much more intuitive than any others I checked (quite a few).

Does everything work fine when not using the pot?

All that's required is a voltage between 0 and 10V, combined with setting the rpm per volt parameter. If you are struggling to generate a 0-10V voltage from a 10V source and a pot, it's difficult to see what Yaskawa could have done to help on that front. The first step might be to use a DVM to check you can generate the correct voltage ranage.

Do you realise that there is a V1000 quick start guide as well as the full manual? The former is slightly more compact.

It's one of those things - the Yaskawa drives are used in all manner of applications in all sorts of industries, so they are very versatile and have many settings. Conversely, if you are experienced with VFDs, you find pretty much what you'd expect. Without wishing to sound smug, I thought it was actually very well written and easy to follow, so I got my V1000 running pretty quickly. As VFDs go, you won't find much better - they are fitted in some real top notch gear.

Murray

I've been I've been using the mill a fair bit over the last few days and the inverter works fine apart from the very non–linear speed control. To be honest I usually rely on the gearbox for nearly everything, but thought the speed control, in conjunction with the fed-rev facility, would be useful for power tapping.

Nikai- interesting to hear you recollect a similar problem. I can easily try a few different pot values (not the sort of thing I usually keep on hand so I'll have to order a few or go to Maplins). If you have a note of,your settings and parameters that might be useful (mine runs a conventional 1kW 4 pole motor and I've set it at 12.5kHz min and 50 kHz max).

Muzzer - I agree that the vfd is very versatile, but therein lies the problem with the manual - it has so much information in it, and on topics which are not relevant to my particular application, that it is difficult to sift out the bits that are relevant for me. For example, the inputs are all programmable by changing parameters, which makes it difficult to find out what the parameters should be for my use of S1 and S2. And there is one parameter that I think should be set to zero, but which steadfastly refuses to change from its current setting of F. Re the 10v - I'm using the on-board 10v reference supply from V+, with 3 wire control using A1 as the control voltage and AC as the common.

Just a thought on re-reading the manual yet again - does anyone think that parameters H3-03 and H3-04 have any bearing on the speed control issue? They are described as the gain and bias of terminal A1.

The answer would appear to be yes - have a look at the manual page 113 Section 4.11 Test Run Checklist item 21.

I have no specific knowledge of this kit - just scanned through the manual out of idle curiosity - but based on a lot of commissioning experience I would suggest the following:-

First check that voltage on terminal A1 swings smoothly from 0 to 10v as you rotate the pot.

Second work through the above mentioned checklist which seems to give a pretty good guide to a basic setup procedure.

If there is still a problem it would suggest to me that one of the many functions that appear to be available may have been inadvertently enabled and I think I would be inclined to reset to factory defaults and start again using the checklist as a guide.

Stick at it - you will get there

Mike

Hi

I can look at the manual and my settings again later this week.

For now, did you set maximum and minimum speed (frequency) by the %? It's a little weird but that's how it works on the V1000 (as opposed to setting the actual max and min frequency itself).

Re the pots, the only place in my city which had any just had a pile of them in a bag. They measured the resistance and the 2K one I first used looked used and I'm guessing it was defective.

Nitai