Broken lathe

[John Rudd]

My 290 lathe is broken….,😢😢😢😢😢

The vfd has failed…an Invertek 1.5kw unit…Powers up but displays O-volts…. Indicative of high bus voltage…which seems odd.
I first put it down to being cold in the garage or damp…but no, brought into the house, sat on a rad to dry out to no avail….
I’ve put a call in to Invertek to see if it can be repaired/how much…a new one is around £200…. Ouch!!

[Muzzerboy]

Wow. For that money you could get a proper VFD. Something like this https://acdcdrives.co.uk/collections/ac-inverter-drives/products/1-5kw-inverter-230vac-1ph-yaskawa-ga500

[John Rudd]

Well not good news….

They say it’s 5 yrs old and has been superceded…..
A replacement is £206….

So I could go to eBay and buy a cheap chink replacement, or inverter drive supermarket has a WEG unit for much less…..choices choices…,,

[John Rudd]

Thought I'd update on this....

after several futile attempts to revive the poorly inverter, I've ordered a new one from Inverter drive supermarket....the WEG one..

The Invertek replacement was coming in at £188, given their lack of enthusiasm to help, I decided to go elsewhere..

Hopefully this one will last me...

[BillTodd]

Of the few vfds I have successfully revived,  the easiest to repair was a cheap Chinese made model, mainly because it used mostly discreet devices and came apart in a relatively simple manner. The typical compact models from Europe/japan use solid state modules which, while available, are impossible to swap.

[John Rudd]

Bill,
The Invertek unit that has failed, has a multi pin power module for the output devices. The remainder of the circuitry is fairly straight forward, there’s a TNY device for the power supply, numerous 8 pin ‘op amp ‘ looking devices and an ARM processor….Repairing is not for the faint hearted, there’s a main board with 2 more boards slotted into it…these need removing to better access….

With the lack of a circuit diag. Repair is hopeless….hence the new purchase..

[Joules]

Shame you bogged off to the back of beyond John.  There be surface mount rework facilities here

Glad you are getting sorted, but if you do want the VFD having a look over and happen to be in South Yorkshire you're welcome to pop by.

[John Rudd]

Joules,
Thanks for the offer….

Like I said above, the lack of a drawing really hampers….Under and over volts on the bus would usually be covered by 2 comparators feeding into the control logic probably handled by the processor….I’ve found this to be the case with earlier Teco inverters….can’t see this one being any different….really.

[Joules]

Mostly my check would be diodes and capacitors, any unidentifiable multi legged beastie with a crater in it deems the job unlikely to be repairable.