VFD problem

Hi was using mill today and it just stopped while doing a fairly heavy cut.There is power going to the VFD but it is not coming on.I have pressed the reset and the run button but no joy is there a trip or any such like that I should look for inside this VFD?

Its probably easier for you to look in the manual as no one here is likely to know the model number.

Doubtful if you will see anything amiss if you open the casing.

Are there any error codes showing?

Was there a pop and a bang, or maybe a burning smell?

Ian P

Don't have a manual.No pop,bang or burning smell.No light up on the screen.

Maybe try removing power for a few minutes then re-connecting. It's a long shot, but low cost to try. It's usually possible to find manuals on-line somewhere if you have make and model number.

It sounds like a fuse or overload but could be anything. Check any fuses after isolating the supply. Try and find a manual on line at least give us a clue with a make and model No.

David

...first check the fuse in the plug. You may find it was a 5A one or something silly.

Murray

Its not the plug fuse.The VFD is an Ls sv008ic5-1f have down loaded and am reading through now.

The VFD clicks for a second every 45 seconds it partially lights up the fans give a kick and then off again.

If the symptoms you see are not mentions in the manual and there are no error codes showing then I suggest you disconnect all the control wiring from the VFD, leaving only the motor and power in connected. Then carry out a factory reset and return the VFD to an 'as new' state.

Input the basic motor details and see if you can control it using the VFDs own buttons. If it is still faulty then my diagnosis would be that it is a real faulty that probably needs a board level repair.

Ian P

Sounds as if it's popped to me. Twitching periodically sounds like a pretty serious internal issue. If so, bin it and buy another, as repair won't be economical.

If you discover a blown fuse somewhere inside, bear in mind that they are fitted to prevent fire or hazard in the event of a circuit failure. Replacing the fuse is unlikely to repair the fault but if you use the wrong sort, you could create a risk of fire or injury.

Murray

Had that problem using the drilling machine doing heavy low speed work.

Waited 3-5min and all back to normal.

Ditto a second time.

Just switched everything off on both occasions.

That was months ago and not repeated since.

Wonder if there was any feedback from motor to the VFD of overheating?

Geoff - We need Noah's Ark.

More likely a temperature sensor in the VFD itself.

I have a Huanwang, which I have modified by disconnecting its internal fan and rewiring it via a thermostat attached to the VFD heatsink. The fan only runs once in a blue moon, or more accurately only when there has been a prolonged period of heavy load. Even then the motor is barely warm and the fan stops within 30 seconds of me stopping the motor.

In spite of its low price I suspect the Huanwang has a slightly oversize internal heatsink compared to many of the physically smaller VFDs.

Ian P

Thanks for all the replies guys I think she is cooked.

The unit is in a state of trip, try disconnecting the motor then power it up. If it powers up OK it is the motor at fault if it don’t it is the VFD .

John

Until you try to run the load a VFD doesn't output anything and will look normal whether there is a short or open circuit on the output.

If you think it's broken you won't lose anything by taking a look inside, start with where the power feeds in and look for anything unusual.

My experience with IMO /Teco inverters, they will display an error if there is a short or open circuit in the ouput stage...This is down to the way the inverter micro monitors over voltage/current oveload conditions, there is also a bus voltage monitor for under/overvolts conditions....Other error messages include temperature sensing of the heatsink.

Depending in the size of the inverter, discrete devices may be used or a dedicated 3 ph " chip" may be used for the high current stages...where discrete devices are used, repair is a lot easier...

Thanks Ian P.

Sounds more like it.

The motor was getting somewhat hot, but even switching the belt to different pulley grooves to get the motor fan speed up, but spindle speed not, didn't help much as the second switch off proved.

Next time will have to sort out a method of forced draught into the VFD enclosure.

The drilling was when I made a holder for my 5C collets using a step drill & 3mm ally sheet.

Geoff - Heating via electric oil heaters and electric blanket, the latter utter bliss.

Cool, Siemens and ABB don't fault until running

Nick,

I ought to have elaborated, the Teco/IMO inverters fault when the Run button is pressed, except for the Bus voltage faults....the drive can be static and will display bus faults, either volts high or low...preventing a start.