- devon, uk
I've got into the box on the cutter block motor. This is what's in there -
That's wired in Delta.
Easiest option will be to go for one (or two if you want to control both motors truly independently) of the 240->380V VFDs.
Braking resistor is used to dump energy when slowing the motor.Thank you.
I have no problem with waiting on delivery. The machine won't get put back together again until the roof is back on, and there's a selection of castings that I need to replace also.
Breaking resistor - I'll read what that is in a moment but I'm guessing somthing that gets plumbed into the vfd stuff?
So, to confirm, I don't oversize the vfd, if I'm buying a pair? It's not much difference in cost and I'm unsure if running them at their given spec is a good thing or a bad thing!
Thank you once again!
I'm guessing I can't just "get a big one" and leave it at that...
Personally, I'd just buy a 230-415V VFD, often referred to as a 'Boost' VFD. I run my workshop from a 7.5KW one, with an idler motor attached to provide a bit dummy load, along with a sine wave filter to kill any transients that might upset my CNC lathe.
However, for a thicknesser I'd wire the VFD direct, as it'll avoid having to oversize the VFD to handle the startup currents involved.
If you're smart with wiring it in, and oversize it slightly, you could have the main motor spin up under VFD control (effectively wire it in after what would be the original push button controlled contactor), and then the original feed motor switch would work as it always has. The switching off the smaller feed motor with the main motor running will hardly be noticeable to the VFD.
The two Boost VFDs I've bought came from CNCWeikin via AliExpress - 220V to 380V VFD - Shop Cheap 220V to 380V VFD from China 220V to 380V VFD Suppliers at CNWeiKen Official Store on Aliexpress.com
The other supplier I know people have used is Ecogoo, although last time I looked, you had to email them to arrange an order.
I think both suppliers are selling the exact same VFD, although there are different series of VFDs, with varying features.
The wadkin that we were discussing needed some other (cast) parts also, and im due to pick them up in about a weeks time (they're miles away, but somewhere i go periodically, so we arranged that id just pick up in person at some point)
Anyway, ive not been desperate to buy the VFDs, as id have no real need of them, but one of the units in my amazon basket has just gone down to £53, so ive hit buy on it. Pretty sure its the one you recommended -
Mini VFD 1.5kW Variable Frequency Drive,Single Phase 220V Input to Three Phase 380V Output mini VFD inverter,frequency converter Inverter for Motor Speed Controller : Amazon.co.uk: DIY & ToolsMini VFD 1.5kW Variable Frequency Drive,Single Phase 220V Input to Three Phase 380V Output mini VFD inverter,frequency converter Inverter for Motor Speed Controller : Amazon.co.uk: DIY & Toolswww.amazon.co.uk
I know i dont need 1.5kw for the drive unit, but it seemed that was as low as they went.
Ill get the other unit at some point, but, as i say, there has been no rush, and it was only really as this one had the price reduction today.
Ill, no doubt, be posting questions when i get the chinease manual through in the post!
At that price, it's a no brainer to buy one. Looks like quite a basic VFD, but it should do the job.
A quick google found the manual, which I've attached for easiness.
We were talking about breaking resistors....