Wadkin UO/S 18/9” Planer Thicknesser (power supply)

[Jitter]

Whichever way you decide will cost about the same..... A new single phase motor will cost you about £320. A VF drive can be had for £140 plus the cost of re-terminating the existing motor in Delta (for 230V) of around £140. A VF drive with step up from 230V to 400V can be had for £300. The advantage of the VF drive route is having electrical braking.

That is not as expensive as I thought, it shows that I have no idea what I am looking for. Thanks for the info, I can run this by my sparky.

 

[Jitter]

Another advantage of a VFD is the ability to program the ramp up and ramp down times. Having the VFD bring the motor up to speed over ~3s hugely reduces the issue of the large in-rush current; meaning less chance of tripping MCBs.

I've not had any problems with the Huanyang units; though all mine are 3hp. A quick Google shows an eBay seller in Prague listing the "220V 4KW 5HP Variable Frequency Drive Inverter VFD Huanyang CNC" for £129. I'd guess you'd need to wire up a 20A line from your consumer unit for this, as you wouldn't be able to power it from a 13A plug socket.

Being able to reduce the inrush current would be a great thing, it is what is putting me off connecting it to the mains. Thanks for the advice.

 

[Jitter]

Then you have got the control system to consider. Plus if it’s not diy only then a lot more than just sticking an inverter or generator on it. Though even if it is DIY then the generator might still invalidate your home insurance.

Thanks for this information.
Is the control system for if I go down the VFD route? Is the control system separate to the machine or would it have to be fitted to the machine somehow?

 

[sploo]

Being able to reduce the inrush current would be a great thing, it is what is putting me off connecting it to the mains. Thanks for the advice.

I find it a huge help. I have a 3hp single phase motor that I can hook up to a mains socket, but the inrush current kills plug fuses (even with just the bare motor). No problems at all with 3hp three phase motors and a gentle ramp up with the VFD (including a 300kg 12" planer).

To partly answer your control question: you can start/stop the motor and control the speed with the VFD front panel, but you can also attach NO and NC switches to terminals inside the case; such that you can have nice accessible red/green start/stop switches where you need. It also makes it easy to add a footswitch for killing the motor. No mains voltage flows through those switches (they're just for signalling to the VFD).

 

[Jitter]

Glad to see the Wadkin in my workshop now in one piece. Cable has been cut off due to damage but the rest of the machine looks good, if I am correct, the machine was built in 1960. A few pics below of the motor and the machine plate, also the motor plate which is difficult to read although most of it is legible.

 

[sploo]

View attachment 97928
Glad to see the Wadkin in my workshop now in one piece. Cable has been cut off due to damage but the rest of the machine looks good, if I am correct, the machine was built in 1960. A few pics below of the motor and the machine plate, also the motor plate which is difficult to read although most of it is legible.View attachment 97929View attachment 97930View attachment 97931

Looks great - but unfortunately that motor won't be able to be (easily) rewired to run at ~240v, so the cheap VFDs won't work for you (they convert single to three phase, but don't change the mains voltage level). A "better" VFD that can output 400v might still be cheaper than a new motor though.

 

[Jitter]

Looks great - but unfortunately that motor won't be able to be (easily) rewired to run at ~240v, so the cheap VFDs won't work for you (they convert single to three phase, but don't change the mains voltage level). A "better" VFD that can output 400v might still be cheaper than a new motor though.

Thanks, I’ll look into the 400v VFD. The motor seems quite old with imperial measurements. I’ll try to figure out it it’s wired for star or delta. I think it has to be delta for VFD’s but not sure.

 

[NetBlindPaul]

Thanks for this information.
Is the control system for if I go down the VFD route? Is the control system separate to the machine or would it have to be fitted to the machine somehow?

Sorry for my delay in reply.
I am currently paralysed from the navel down in a hospital bed due to cancer and I am just not as quick as I would like to be.
The normal supply to the machine will run the control system start/stop etc.
With a vsd alternative means of control are required.
The original buttons on the uos for example are a bit unsuitable.
Though similar could be interfaced to the vsd.
I think you might be unlucky with the motor windings but good luck.
It is an old imperial motor too.
So a bit of mechanical work to fit a metric one.
Also I don’t believe that you’re going to get full motor torque running on 230V ph-ph instead of 400.
I would be unhappy unless I had a single button stop with the maximum possible deceleration to stop. then safe torque off implemented at the vsd.
Again I reiterate I trust that this is not for use in any kind of business and advice that there are other things to consider that are quite serious but difficult to get right in this manner of communication.
More and detailed advice will be necessary for this work to be undertaken safely.

 

[deema]

That’s what is known as an engineering challenge.
The motor is a special, none standard flange bolt hole spacing and it has an extra long shaft (5” extension).
So, firstly take off the cover electrical cover on the motor, sometimes they are dual voltage, just dont put it on the plate.

 

[Jitter]

Sorry for my delay in reply.
I am currently paralysed from the navel down in a hospital bed due to cancer and I am just not as quick as I would like to be.
The normal supply to the machine will run the control system start/stop etc.
With a vsd alternative means of control are required.
The original buttons on the uos for example are a bit unsuitable.
Though similar could be interfaced to the vsd.
I think you might be unlucky with the motor windings but good luck.
It is an old imperial motor too.
So a bit of mechanical work to fit a metric one.
Also I don’t believe that you’re going to get full motor torque running on 230V ph-ph instead of 400.
I would be unhappy unless I had a single button stop with the maximum possible deceleration to stop. then safe torque off implemented at the vsd.
Again I reiterate I trust that this is not for use in any kind of business and advice that there are other things to consider that are quite serious but difficult to get right in this manner of communication.
More and detailed advice will be necessary for this work to be undertaken safely.

Thanks for your reply, I am sorry to hear that you are unwell and wish you all the best with any treatment you are getting. My mother has this year has beaten her cancer with immunotherapy while she was not expected to do so, it goes to show that no matter how bad things are, always stay positive because everyone’s battle with this is different.

Thanks for taking the time to respond, it is greatly appreciated.

best regards,
Paul.

 

[Jitter]

That’s what is known as an engineering challenge.
The motor is a special, none standard flange bolt hole spacing and it has an extra long shaft (5” extension).
So, firstly take off the cover electrical cover on the motor, sometimes they are dual voltage, just dont put it on the plate.

Hi Deema. Thanks, I will check this out. Unfortunately I know nothing about motors, I took the end vent cap off the end of the motor yesterday to find a fan that is very clogged with dust. Presumably, I am looking in the wrong place and will check for another plate to remove today and see if I can find the electric connections to the motor and relay some pictures.

 

[Jitter]

 

[Vann]

Six wires into your terminal box. I'm not an expert, but I think that's a good sign (that it can easily run on 240v, 3phase).

Good luck.

Cheers, Vann.

 

[Vann]

I am currently paralysed from the navel down in a hospital bed...

Sorry to hear that. I wish you the best recovery possible.

Regards, Vann.

 

[sploo]

Agreed. I'm more familiar with the terminals being in a 3x2 layout, with solid metal strips that can be moved between the two sets to reconfigure the motor between star and delta. However, from Jitter's image it looks as though there are flexible wire links that can be moved.

I can't see the markings on the bottom terminals, but A1, B1 and C1 are clearly the three input live terminals. With reference to the attached image (from https://www.granthamelectrical.co.uk/images/additional/star delta.png) those three lines are L1, L2 and L3; with A1, B1 and C1 usually being referred to as U1, V1 and W1.

It looks as though the motor is currently wired as Delta; which makes sense for a 400v input.

You need to remove the links between your U1<->W2, V1<->U2 and W1<->V2 (from the attached image) and use the links to join W2<->U2<->V2. That should now allow the motor to operate from 230v (with a three phase VFD).

As noted in the bottom of the image - you can swap any two of L1, L2 or L3 to change the motor direction (if you find it's spinning the wrong way).

 

[Vann]

...if I am correct, the machine was built in 1960...View attachment 97931

We may never know, but I believe you're right - that it was built in 1960.

It used to be thought that the first two digits of the Test Number gave the year of manufacture for Wadkin (Green Lane works) machines, but this was later found to be greatly wrong. However for Wadkin-Bursgreen machines (which were manufactured at the former Bursgreen factories) I believe this holds true. So until information comes to hand that proves otherwise - you can assume that your machine was built in 1960.

Cheers, Vann.

 

[deema]

The motor is connected in Delta which is bad news. It means that the 400V is seen across each coil rather than two coils which it would have been if it had been wired in Star. I.e. each coil needs 400V to generate the field to run the motor properly. A Star Delta motor designed to run on 240V 3ph is wired in Star for 400v and Delta for 240 3ph. A 240V VFD won’t work.

There are 4 options I can think of, each offering different challenges.
1. Easiest and most expensive is to buy a Rotary converter. It takes single phase and generates a true 400V 3 phase. It’s a static converter with a slave motor attached. This would be IMO the best solution. It would also allow you to buy and run other 3phase machines without worrying.
2. Static converter 400V. These need to be matched to the machine they are running, they have a small window to motor KW they can run as they are ‘tuned’ to a size of motor. They are cheaper, but your machine won’t have as much power as they dont generate a true 3 phase.
3. 400V VFD. They are expensive, not approved I don’t believe and need a bit of rewriting of the motor controls which is best left to an electrician if you are not absolutely sure what you are doing.
4. Replace the motor with a single phase motor with both mechanical and electrical changes to make it work. This will need either a custom motor or for you to reshaft a standard motor / or build an interface / new pulley system.

 

[sploo]

The motor is connected in Delta which is bad news. It means that the 400V is seen across each coil rather than two coils which it would have been if it had been wired in Star. I.e. each coil needs 400V to generate the field to run the motor properly. A Star Delta motor designed to run on 240V 3ph is wired in Star for 400v and Delta for 240 3ph. A 240V VFD won’t work.

Ah. So reconfiguring that motor as star isn't going to work then?

 

[Spectric]

A "better" VFD that can output 400v might still be cheaper than a new motor though.

You will not get a VFD that outputs 400Vac, not because they cannot be designed and manufactured but because invertors are restricted to the output being equal to the input voltage due to regulations imposed by DNO's. You could use a digital convertor that would give you 400Vac three phase but it will not give you the variable speed. You could also add a softstarter to reduce inrush current if you find it necessary.

 

[Jitter]

Thanks everyone for your advice. I think ruling out changing the motor etc is a good idea just now due to complications that will inevitably arise. I am keen to get the machine working as it originally would with full 3 phase power, not so bothered about the variable speed at this point in time, I’d rather get the machine running with true 400vac if that is the correct term. So with that being said, I guess without simply attaching it to a huge generator, it leaves me two options I think. A 400vac digital converter with the last configuration that Spectra has suggested with the soft start or a rotary 400v static converter with the motor attached for the startup current, I like the idea of being able to hook up future machines to this also. I would only ever be using one machine at a time anyway.