Buying a 3 phase planer thicknesser for single phase supply

[Prizen]

Just wondering if running a 3phase machine is ok with a converter where I only have a single phase supply. ?

 

[shed9]

Yes is the short answer but are you referring to a convertor or an inverter.

 

[Prizen]

Thanks . Any recommendations on a converter or what to consider when purchasing one?

 

[shed9]

Depends on the model and wiring of the motor itself but an inverter drive (also known as Variable Frequency Drive) is the way to go.

I would personally go for a branded device as opposed to the Chinese devices on Ebay. Go with an IMO, Control Techniques or similar.

What is your machine?

 

[Prizen]

Looking at a sedgewick m b 310 but not purchased yet.

 

[Ttrees]

Does it have a separate motor for the feeder?
I haven't seen anyone hooking up a VFD for a feeder on a thicknesser, but can't see why it wouldn't work.
Tom

 

[GK1]

I run my modern three-phase Sedgwick MB310 with two inverters.

The feeder motor on the Sedgwick is a Dahlander configuration which expects 440V at either of the two feed speeds. It can't be configured for 240V operation at rated speed. But it can still be done successfully with a 240V single to 3 phase inverter if you are prepared to give up the two speed operation.

Have a look at this document: https://inverterdrive.com/HowTo/240V-Su ... -AC-Motor/
If I understand it correctly, a 3-phase 440V motor will run correctly at 240V 3-phase without risk of over current as long as the supply frequency is set to 29Hz. The shaft speed is reduced of course.

So the inverter for my feeder motor is set to 29Hz and the output of the inverter is connected to the feeder speed control selector in the Sedgwick panel. It's permanently set to position '2', high speed, but because of the reduced frequency the feed rate is the same as position '1' if it was connected to 440V.

The 3Kw cutterblock motor is wired in delta and runs correctly from it's own inverter.

I've been running my MB like this for a couple of years and it's fine. I live with the feed rate always on 'slow' (even though the selector is set to 'fast'). The cutterblock motor inverter is set for a brief run up to speed, so no belt squealing, and stops in 10 seconds. The feeder motor inverter is set for a much shorter run up and a freewheel stop.

By the way I think older Sedgwicks had the feed driven by the cutterblock motor.

 

[RogerS]

OK...my two penn'orth. Where I live the mains supply is 'challenged'. Basically the house is fed from a too thin 1/3 mile extension cable. So all my heavy-duty machines had to go when we moved here.

I was planning to use a Hammer C3-31 combination machine which has three motors..only one being on at any one time...selected by a switch on the Hammer. So the plan was to bring out the Hammer controls (on/off/emergency stop) as controls to the 240v mains feeding the inverter. The output of the inverter feeding the 3-phase input to the Hammer. The inverter in question also required the three motors being converted to run off 240v 3-phase. Also this route was needed to keep all the braking functional etc.

I bought the inverter - a Yaskawa V1000 - and then that's when it all went pear-shaped because there was no easy way that I could find to get into the machine to do the modifications needed.

So Plan B - I bought a Transwave rotary converter. In hindsight, if I'd known that this was the way things would have panned out, I'd never have gone for the combination machine...just bought 3-phase separates.

Your situation, you might not have to go through any mods to the Sedgwick and so an inverter will suit you fine. I'l be putting my brand new unused inverter in the For Sale section shortly.

 

[Prizen]

Starting to get worried. Thought this might be straightforward

 

[RogerS]

Starting to get worried. Thought this might be straightforward

If you need reassurance pop over to Thewoodhaven2.co.uk where Bob (9fingers) is a motor guru.

Check out his detailed document here

https://drive.google.com/file/d/0B_GZrX ... sp=sharing

 

[shed9]

Don't want to add to the problem, more of a heads up. Inverters don't like RCD's unless they are the right RCD. Would need to check but I think I'm running a Type B.

You need to factor in some local advice / work into the mix basically.

 

[RogerS]

I also seem to recall Bob (9fingers) saying that unless you get the controls dead right, it's easy to low up the inverter.

The simplest and easiest IMO is a rotary converter from a reputable supplier.

 

[Prizen]

Went to see it just now.

So the bad news; 2 motors, and the cast iron table has a nick just adjacent to the cutter; although its small, perhaps 2 mm diameter.

Good news ( I think)
I bought it for 800 euro

 

[porker]

I also seem to recall Bob (9fingers) saying that unless you get the controls dead right, it's easy to low up the inverter.

The simplest and easiest IMO is a rotary converter from a reputable supplier.

As RogerS states the easiest route is to go for a rotary converter so you effectively can supply the whole machine with what it is expecting ie. a 3 phase supply. If you go the VFD route then most need to have the outputs permanently connected directly to the motor which means the switches etc. generally need to be rewired as inputs to the VFD. Also the motor voltages must match the output which may mean changing the configuration of the motors from Star to delta. Most modern motors can be changed by altering a few jumpers under a plate on the motor. The motor plate will usually indicate whether it is dual voltage. If the RCD is a problem it is not difficult to get a C type as a direct replacement on your CU.
I rewired a bridgeport mill from 3 phase to use 2 VFDs and it works great and gave me variable speed but probably not something you need so much on a PT. I didn't have any issues with my existing RCDs.

 

[tomatwark]

One big advantage with buying a rotary converter is you can run different machines from it, so it give you a lot more scope to pick up other 3 phase stuff.

 

[Prizen]

Any recommendations on a best value rotary converter?

 

[RogerS]

One big advantage with buying a rotary converter is you can run different machines from it, so it give you a lot more scope to pick up other 3 phase stuff.

Ain't that the truth ! =D>

I wish I'd had my rotary before I got the combi.