Warco GH1330 conversion from 440v to 240v

[cejm78Participant @cejm78]

A few months ago, I asked for some advice regarding the purchase of a lathe. After careful consideration, I decided to buy a second hand Warco GH1330. The lathe was delivered in December but I had no time to look at it.

The lathe I purchased is a 3 phase lathe and I only have 1 phase available at our property. We had National Grid out last month to install some protective covering over our electricity supply, as we need scaffolding put up around the house.

I asked them how much it would cost to put 3 phase in. As a rough estimate they said anything between £50k-£80k!!

So obviously, that won’t be happening.

I had already planned to convert the lathe to run via a VFD, so nothing was lost. Peter Symonds at Inverter Drive Supermarket has been very helpful and recommended the Invertek Optidrive E3 as my VFD.

Last week I started the process of fitting the VFD. Initially, Peter had made some changes to the wiring so that the lathe could be reverted back to 3 phase. After some consideration, I decided to remove all the excess parts as I am not planning to run her ever on 3 phase.

A new SUDS pump had to be purchased as the current 3 phase pump would no longer work. Warco had a 1 phase pump in stock and for just shy of £100 it was delivered to me.

This means that the lathe has now two power leads. One lead to power the VFD and another one to power the SUDS pump.

A very rough wiring layout was made to make sure that all functions of the lathe work. With everything working, I can now tidy all the cabling away and rework the electrical cabinet.

Items bought at this point:

-Lathe

-240v SUDS pump

-Invertertek Optidrive E3

-240v fuse block

-24v relay

-1mm2 hook up wire (black and red)

-Crimp terminals

-Emergency stop button.

I will update again as I progress.

The VFD all wired in.

 

The VFD installed on the lathe. Still want to make a protective cover so that it can’t be knocked.

[Robert Atkinson 2Participant @robertatkinson2]

I’m impresed.
A VFD that actually IS suitable for use outside an enclosure and connection to a domestic supply.  It does however need screened cable for both the mains input annd motor leads. The screens need to be properly grounded as well. See page 18 of the manual

https://www.motorcontrolwarehouse.co.uk/amfile/file/download/file/4373/product/2667/

Note it’s only the IP66 rated units with a cable gland box that are suitable fr mounting without an enclosure.

 

[Andrew TinsleyParticipant @andrewtinsley63637]

In case anyone else is considering buying a single phase suds pump to replace a 3 phase version, maybe this may be of help.

I had a Myford 3 phase suds pump and tank. Conversion to single phase was straightforward at the cost of a capacitor (approx £4). These pumps are ideal for conversion using a Steinmetz circuit. In the case of the Myford pump, even the capacitor fitted neatly into the motor.

There are those on the forum who frown on such a conversion. Pay no heed to them, they have never tried it and simply quote doom from internet sources and they have no practical experience! This particular conversion works well and has been doing so for many years.

Andrew.

[cejm78Participant @cejm78]

Robert, in theory you are correct if you want an EMC compliant installation. In the case of a lathe at home, this does not need to meet EMC compliance.

Even for an EMC compliant installation, a 1 phase can have a normal unscreened supply lead. However, it should have a screened lead between VFD and motor.

Andre, that is good to know. I did not think to look if I could convert my 3 phase suds pump. Oh well, I now have a spare. 😁

[john fletcher 1Participant @johnfletcher1]

As Andrew above says, when using a 4 Micro Farad capacitor, most if not all 415 volt coolant pumps will run on 240 volts. I have used ex fluorescent lighting capacitors for my friends when doing them a  conversion job.

[john fletcher 1]

On john fletcher 1 Said:

As Andrew above says, when using a 4 Micro Farad capacitor, most if not all 415 volt coolant pumps will run on 240 volts. I have used ex fluorescent lighting capacitors for my friends when doing them a  conversion job.

I have done similar with a coolant pump on my milling machine but I had no idea what specification for the capacitor.

Is 4 microF suitable for all pumps? Is there any other parameters I need to check?

It works okay but I always wondered if the capacitor was sufficient in size.

 

[cejm78]

On cejm78 Said:

Robert, in theory you are correct if you want an EMC compliant installation. In the case of a lathe at home, this does not need to meet EMC compliance.

Even for an EMC compliant installation, a 1 phase can have a normal unscreened supply lead. However, it should have a screened lead between VFD and motor.

Andre, that is good to know. I did not think to look if I could convert my 3 phase suds pump. Oh well, I now have a spare. 😁

Hi,
Why do you think a lathe at home does not need to meet EMC regulations?
Anything electrical must meet EMC standards in the UK. This applies even if the equipment is a one off.

I also just noticed note 6 in section 4.12 on page 18 of the manual. The drives don’t meet radiated emissions for category C1 (domestic and commercial) without “additional measures”

Robert.

 

[cejm78Participant @cejm78]

Made a bit more progress converting the lathe. Had to change a few micro switches from Normally Closed to Normally Open so that both the Emergency stops work. It only requires you to change a wire from the NC contact to the NO contact, so quite easy to do.

On this VFD, you connect 2 (run forward) to 3 (run reverse) then it stops the motor. You can then change the parameters so that the motor uses AC Flux Braking instead of just coasting to a stop. Hence, why the Emergency stops had to be changed to Normally Open.

I also installed a relay, as I have two 240v leads, I wanted the power light to come on whenever either one is powered. Took a little bit of time to incorporate it, but it is working as it should. Just need to tidy up the wiring.

Had to order another fuse, a contactor and a thermal overload relay. The relays that were previously on the lathe didn’t have the right operating range. This should all be delivered tomorrow, subject to Royal Mail and DPD.

A batch of oil was delivered today so that the lathe can be given a service. I have no idea how old the current oil in the lathe is.

Hopefully a few more pictures tomorrow.

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