new Harrison L6 mk3

You wouldn't normally use the lathes switches with an inverter James, it wires direct to the main motor to provide 3 phase.

You could use some of the machines existing switches to control the inverter, but most people ignore them and use a dedicated pendant box, with for/rev, jog, speed control and e stop switches etc. You wire this to the low voltage side of the inverter using 8 core alarm wire.

Of course this means you need to come up with a separate solution to power the suds pump, but being a small motor, this is usually pretty easy to contend with.

Edited By Alan Waddington 2 on 14/01/2017 19:13:46

You could jury rig the suds pump to run from single phase with a capacitor....there are many examples on google...so need for a further inverter or any other complications

James, congrats on your purchase.

You need to also now join the Yahoo Harrison User group.

They are currently running articles on an M300 VFD convertion so you may pick up a lots of useful tips. There may also be a few useful and applicable files for downloading as well.

Malc

They say a picture paints a thousand words......so hopefully this might help.

**LINK**

Sorry to muscle on in this thread but it is discussing a similar problem I have with my new (to me) Tom Senior M1 mill. This is a picture of the motor plate.

'

This is a picture of the wire terminals in side the motor.

This is the switch box on the side of the machine.

Oh dear I am having iPad problems, the switch box picture has jumped to the start of the thread.

My question is will I be able to convert this motor to delta?

Am I right in assuming this switch box won't work with an inverter?

Edited to add, my inverter has 4 wire plus an earth wire coming out of it, the motor on the mill has 3 wire coming out of it. Any advice gratefully recieved.r

Edited By ANDY CAWLEY on 14/01/2017 23:17:59

My old Tom Senior motor was Star only, so I had to dig out the Star point. Yours looks like a Star/Delta motor, so you can configure it to Delta by simply moving the brass dogbone links. There might be a diagram under the terminal cover.

Not sure on your inverter wiring without more info. Probably worth downloading a manual if you don't already have one.

The inverter output should be wired direct to the motor, no switches in between

This explains it better than I can......http://www.drivesdirect.co.uk/Downloads/InvertertoMotorWiring.pdf

Edited By Alan Waddington 2 on 14/01/2017 23:58:52

Alan,thanks for that.

Converting to delta looks like a probability for my motor.

As for the manual I do have one but it might as well be written in Sanskrit as I don't really understand it. I must ring Drives Direct, they were very helpful when I bought the magic box from them.

If you can get a photo of the terminal block aswell that will help. You are right though, that is a single voltage dual speed motor which is hard wired for star mode. That might complicate things a little further.

Someone else who knows more about 2 speed motors will have to chime in here as I'm at the limit of my knowledge, but your motor will have an internal star point which is effectively the A1, B1 and C1 terminals which at the moment are not accessible to you, and is what is stopping you configuring as delta. A dual speed dual voltage motor of your type would have all 9 terminals accessible.

This is the suds pump, i think i could wire this seperate 230v?

Thanks

James

Yeahh, thats a dual voltage suds pump so you can easily wire it for delta operation. If you pop the 3 screws the lid should come off to expose the terminals. You should see 6 terminals. It will be configured as per the bottom right diagram below with links running across the top 3 terminals. The links need changing to represent the bottom left diagram, hopefully there is a spare link in there as you need 3 links for delta and only 2 for star. L1, L2 and L3 are the three phase inputs coming from your inverter.

You will need to do some more work if you want to run it from single phase 220V instead of inverter 3 phase 220V, which will either be to dury rig some capacitors up to bodge up the remaining phases, or run from an inverter.

For your information, I run both my main lathe motor (star point dug out and converterted to delta) and my suds pump motor (configured for delta) from a single inverter without any issues. The only thing I don't do is turn on/off the suds pump motor while the lathe/inverter is running. i.e I turn the suds pump switch on before I start the lathe/inverter and switch the suds pump switch off after ive stopped the lathe/inverter.

Graham

Well, I followed the advice and rang the Drives Direct technical help line. What wonderfully helpful chap I spoke to, I can't praise them highly enough.

It turned out that I had bought from them, all those years ago, a Digital Phase Converter, which, now I think about it I do remember and it wasn't cheap. This device rather than an inverter has what is in effect a"plug and play" capability.

I remember now I bought a Converter rather than an inverter because I didn't want to have to buy a separate gadget to match each individual 3 phase machine that I might buy in the future. Not a cheap route but now I understand a bit more a very good decision.

I now have a 400 volt 3 phase plug socket on the wall that I can plug any machine upto 5 HPC into.

There is no need to mess about converting to Delta, the stop start button and the remote panic button on my mill work, my lathe has 3 speed 3 hp 3pase motor on it which does not give any problems. Following my conversations today I can now, at the press of a button, reverse the motors.

To say I understand it would be something of an exaggeration but I now know better how to make it work thanks to the technical assistance from Drives direct. I have no connection with them other than as a very satisfied customer

Not a cheap piece of kit on the first purchase but it will run any machine individually which is what most of us shed engineers do any way, just plug and play😀.