vfd question

I have just fitted my boxford lathe with a Chinese xsy at1 vfd. As far as I can tell the relevant parameters are set and the vfd works as it should up to 50hz. If I try to run above 50hz then it cuts out and I get an error 6 message which is over current protection. I believe this refers to amps but at 50hz it is only drawing approx. 5 amps. Does anyone have any ideas what may be causing the problem and how I might fix it.

Is it a star delta motor or a star motor with the star point dug out ?

Just looked at an example of it on youtube. That VFD is a potential death trap. It should only be used inside an enclosure which is securely closed to access.

The reason? The mains voltage connections are accessible without using any tool or having an interlock. I expect that defies UK laws on such things. All the VFDs I have come across have a screwed cover to the high voltage connectors.

Clearly, I would think, it would not get a CE certification if it were ever checked and tested for safety.

Hi Alan, the motor is inverter rated and configured in delta.

Ah ok, interested as i had this recently with an older motor with the star point dug out.

Inverter Worked fine up to 50 hz but tripped on current overload at 65hz.

Tried same inverter with same parameter settings on a newer star/delta motor and it didnt trip.

Hopefully someone on here will throw some light on the problem

Hi not done it yet, you are quite right in what you say. I had noticed it and it will be installed in an enclosure when I have got it working properly.

Thanks for your input Alan.

1st thing is the motor rating plate saying 415v star. 240 delta.. If so then that is correct. Yes there is a parameter that needs configuring. I have not used the Chinese ones. Currently using a Omron on the lathe & a Toshiba on the mill. It took me days to get the Omron working correctly & now I can go as high as I want on the frequency, but set a upper limit at 85. The Toshiba would not run over 50hz. I have been working away at it for a couple of days now, still struggling with it. Not sure on the Chinese , but the ones I have, come with a 160 page manual to totally baffle you & something like 100+ different settings. I am an ex electrician & fitted lots of these in the past. Now a retired old fart that has forgot more than I knew. Best of luck. There will be setting in there somewhere. One of the settings on most inverters I have come across is the full load current of the motor in use. Maybe a starting point.

Steve.

Hi Steviegtr, yes the motor is dual voltage. it is configured in delta and the parameters set for 220v and 50hz. I had the maximum operating frequency set to 65hz. I have set the maximum voltage for the motor but i can not see a setting for the amps. There are approx. 80 parameters many of which I do not understand and the instuctions give no clear explanation.

I really feel for you John. Honestly I have sat in the garage for hours going through different parameters. Thinking all the time that the inverter was faulty cos it cannot be me that is that dumb. Only to eventually find the setting. I was in bed one night & came up with what I thought was a solution to a setting. I got up & went into the garage at silly o'clock & started prodding. All to no avail.

My Toshiba one would not run over 50hz. I eventually found a setting deep in the memory. Parameter F703. I set this to 85hz. Although I had already set the upper & lower limits in another setting ,which did not work. Suddenly wallar 85hz worked fine, great. Today went to use the mill & set it going at 70hz. It ran fine for about 10 seconds & then started hunting up & down. So start all over again. With the expensive units they have all the standard settings. Then what they call extended parameters. Very baffling. All I can say for the one you have is maybe try a google search or youtube to find your model. There could be someone with the same problem as you.

Steve.

John, maybe this may help - I believe it is a setup for your VFD.

Parameter P78 thru P85 seem to be current settings ( in mA). This example is set for 7amps (7000mA)

Voltage settings, max and min frequencies, etc, to be set as you need, not necessarily as per this example!

Joe

Edited By Joseph Noci 1 on 21/03/2020 06:55:03

Steviegtr I have already looked on you tube without success.

sit down, RTM and think logically....It is pretty simple, If you cant understand it seek help here. See one of my previous posts on a search for AT1 thread.

you should have a parameter P78 main current overload

set that at the calculated normal load current for your motor + 20% or what you feel comfortable with (it is expressed in mA so 6A would be entered as 6000)  (the default by the way is 3000 which is why you may be experiencing trouble)

set parameter P24 to 2 seconds

make sure you have set P0 through 10 correctly (not what is the table above which is for high speed spindles)

Have regard to P12 for you application

Review the ramp times P26 P34 P42 (and others if you are using them) I have come across some units Hz/s has been a multiple of 10.

Avoid using the factory reset unless you have been through all of the parameters and written them down - sometimes the defaults are not as stated on the printed sheet and I also suspect there may be some hidden non accessible ones.

Contrary to the received blather on the net, these are excellent high quality units, let down by poor end user manuals, the connections are no more exposed than in the majority of older industrial inverters. The boxes are intended for industrial panel mounted use, but sold onto the hobby market hence the howls of outrage. The Chinese assume that the people purchasing this class of device will be smart enough to enclose the devices or carry out some other form of risk mitigation.

Edited By Martin of Wick on 21/03/2020 09:55:27

Edited By Martin of Wick on 21/03/2020 09:56:58

Edited By Martin of Wick on 21/03/2020 09:58:28

Edited By Martin of Wick on 21/03/2020 10:00:11

Edited By Martin of Wick on 21/03/2020 10:03:46

Martin,

I might agree with you if there was not a potentiometer knob on the panel - clearly there for the user to change speed by it.

All consumer items have to be ‘idiot proofed’. As I said ‘potentially’. When was the last time you had a 13 amp plug where you could remove the top while still plugged into the mains? Two layers of insulation is the norm for conductors, unless inside an appropriate enclosure.

Is this: LINK the one?

Testing the earth continuity at 04.17 it appears that the earth is also switched via the locking pushbutton
Not a good idea!

Herein is the problem.... The unwary user will assume these are 'consumer' units because they are cheap and readily available, like some sort of pistol drill speed controller in the olden days! That they are not, they are based on industrial devices and provided with no concessions to the unwary or inexperienced. So yes beware and make your own risk assessment.

I would hope that most sensible people would check / set up their device using the panel and then construct a remote pendant to suit their requirements and secure the nasty dangerous bit in its own box.

If access to the keypad is required, it can be mounted in an enclosure so only the front upper portion is exposed.

joseph noci 1, my instructions do not have a setting for P25 which according to the set up you posted is for number of poles. The VFD does have P25 so I will try that. I have P21 set to 1420 which I thought was for the rated speed of the motor. The VFD trips out at 1420 so I will increase that and see what happens. Thanks for your help.

Well that is just user plain old error, not a fault of the inverter.

An earthing point is provided on the device into which themotor earth and incoming 220v mains earth should connect unswitched.

P21 correct - enter plate speed which if you motor is 4 pole will 1400 or so There isn't usually a P25, as setting the motor speed performs same function (more or less). If you set a higher plate speed, only the display RPM will be affected.

Although many people seem to intstall VFDs by screwing them to the wall this is not a satisfactory or safe installation. They are all intended to be fitted in an enclosure to keep swarf and coolant away from some dangerous voltages and sensitive electronics. Many drives will be fan cooled and these will suck any airborne rubbish that passes, they often have no filters, relying on the cabinet to be ventilated and cooled if necessary with filtered air. Most drives will have no strain relief for the cables so snagging a flying lead will possibly damage the terminals and possibly create a hazard or damage the drive electronics. Some will have a cage clamp to terminate screens properly but this sort of fitting will be on more expensive industrial units. What we do in our workshops is of course our own business but perhaps we should aspire to achieve a more professional installation which is safer and more reliable.

Mike

Edited By Mike Poole on 21/03/2020 10:51:58