Lathe conversion

[chris-law]

A vfd is only for duel voltage motors , some of the m300 motors are 400 v only , my t300 was , I've just upgraded to a duel voltage 3hp motor and a Mitsubishi s720 vfd , we have wired it to work with the original switches , no coolant on mine though , I'm going to convert the lamp to 240 also .

 

[mr_splatter]

You can get VFDs for 415V systems from a 230V supply but they are fairly dear. £400 for a 3HP unit. The other alternative is to get a rewind shop to get a centre point tapping on the windings which is sometimes possible.

 

[Burdekin]

Thanks for all of the advice guys, appreciated. Yesterday I was thinking this was going to be relatively straight forward, I should have known there would be plenty of little things to sort.

The one good thing is my electrician mate is quite a clever guy and Direct Drives are there to help and advise as well. I did think of going the cheap Chinese option but thought I should support a UK business.

I will let you know how I get on.

 

[pactrol]

Hi guys
just in the process of converting my M300 from 3ph to single
Ive purchased a weg 2.2 kw 230 v single to 3ph inverter which should be fine as the
2.2kw 3hp motor fitted to the lathe is dual voltage ie 230/ 400
now this is where you can help me How the hell do you get at the bolts to remove the motor as I need to change the links from delta to star = 230 3ph so my inverter will run it

thanks

 

[mike os]

probably cheaper to change the motor as well, rather than buy a true 400v inverter for a single voltage motor.... it was for me anyway iirc new motor was only £100-120 (not going to get a lot of use but motor was continuous rated)

 

[Shox Dr]

Why do you need to remover the motor?

 

[ronan]

No need for a 7.5hp vfd to run a 3hp motor , the vfd starts the motor slowly (user adjustable up to 30 seconds or more) so there is no or a greatly reduced inrush. Also i think its a definate no-no to run more than one motor at a time off a vfd.

The vfd's are getting cheaper all the time , i bought a 2hp abb one for my mill in january from halcyon drives in leeds and it cost £115 + delivery, an absolute bargain compared to what they used to cost.

 

[armalites]

Unless the motor is really old very often you just need to change the config to change it from 415 3ph to 240v 3ph. Normally just 3 links. That would save you some money on the inverter.

I see mention of a inverter providing 3ph power to workshop.

Inverters are motor drives and do not provide 3ph power.

 

[Keith 66]

I just converted a Boxford CUD to single phase, was lucky enough to find a single phase motor that would fit, what fun getting it in, pulley on wrong way round, barked knuckles taking motor out to turn it round, put it back in & found the motor shaft now was too long, motor out again to cut half inch off, much gnashing of teeth & profanity then find i left the new motor lead 2" short.
More profanity! And i thought it was only going to take an hour,

 

[Burdekin]

Unless the motor is really old very often you just need to change the config to change it from 415 3ph to 240v 3ph. Normally just 3 links. That would save you some money on the inverter.

I see mention of a inverter providing 3ph power to workshop.

Inverters are motor drives and do not provide 3ph power.

I've sent Direct Drives an email to ask the questions but this is from their website: "You can use this type of *DIGITAL PHASE CONVERTER in two ways,

In the conventional mode it will allow you to run a directly connected 415 Volts 3 phase motor up to the supply capacity of the converter so 7½ HP in the case of this converter,

It will give you all the normal inverter function of motor control like :-

SOFT START - You can program the unit with the required motor start time and the inverter will ramp up the motor to the requested running speed in the time set,
FULL MOTOR SPEED CONTROL - Advanced VECTOR control will allow you to have the motor running at very low speed BUT will full power(take*motor cooling into account if using for long periods at low speed)
ELECTRONIC BRAKE - STOP the motor within a preset time
You can use the removable front panel to control the motor and select forward/reverse or you can use one of the many remote control boxes we stock to control the motor(See EBAY ),


PLUG & PLAY MODE

Another SPECIAL feature of this converter is the ability to run it in Plug and Play mode,

In this mode you can take the 415 Volts output of the converter and connect it to your machine so that the existing machines START/STOP buttons and switches will still work to control the machine as if it was connected to a factory 3 phase supply,

You need to take into account the motors starting requirements when sizing up the converter for Plug and Play mode, normally a 3 phase motor will require at start up a surge of 3 to 8 times the normal running power and the size of converter needs to be large enough to provide this power,*

Unless the machine has a very high start load for example in the case of a planer machine because of the cutter block's inertia you can go for a 3 x overload rating, as an example the main spindle motor on a 2HP Bridgeport Mill will require a 6HP surge to get it going,

All this range of DIGITAL Plug and Play Converter allow you to take a 150% overload for 30 seconds so the 6HP starting requirement of the 2HP mill can be accommodated by this 7½ HP converter,

As the output from this unit is a DIGITAL output you can only use it to power normal motor/switch loads and not any items that contain electronics,

If you need to provide power for an item with electronics of any type you will need to fit a SINE WAVE FILTER(See )*to the output, once you have this fitted then you can power machines with electronics in them and even running a CNC machines is possible,

If your machine required a NEUTRAL then this can be generated by fitting a NEUTRAL GENERATOR at the output of the SINE FILTER BUT as an N line is normally just a way for your machine to get back a 220 Volts supply we can oftern talk you through feeding a 220 Volts supply to the machine to power this part of the load thus saving you the cost of an extra part,

This type of Plug and Play system when correctly sized can be used to power a whole workshop via a ring main,"

 

[pactrol]

Unless the motor is really old very often you just need to change the config to change it from 415 3ph to 240v 3ph. Normally just 3 links. That would save you some money on the inverter.

I see mention of a inverter providing 3ph power to workshop.

Inverters are motor drives and do not provide 3ph power.[/QUOTE

solid state inverter also alows variable motor speed & soft start function
requires dual voltage motor 400/230 3ph inverter 230v 3 phase out variable frequency
unfortunately the terminal box on my motor is located under the chuck head
so I cant access the terminals to swap the links to star ( 230v ) 3ph
so need to un bolt the motor but don.t see how to get at the mounting bolts
obviously there has to be a way on doing this

 

[chris-law]

Unless the motor is really old very often you just need to change the config to change it from 415 3ph to 240v 3ph. Normally just 3 links. That would save you some money on the inverter.

I see mention of a inverter providing 3ph power to workshop.

Inverters are motor drives and do not provide 3ph power.[/QUOTE

solid state inverter also alows variable motor speed & soft start function
requires dual voltage motor 400/230 3ph inverter 230v 3 phase out variable frequency
unfortunately the terminal box on my motor is located under the chuck head
so I cant access the terminals to swap the links to star ( 230v ) 3ph
so need to un bolt the motor but don.t see how to get at the mounting bolts
obviously there has to be a way on doing this

My lathe a T300 , the motor is bolted to a plate which in turn is bolted to the lathe by 3 17mm bolts , its tight on the back one but thats the best option .

Chris

 

[Burdekin]

Found this on another forum:


Originally Posted by CalG
To your post, I believe it is a member in the UK who stated that he uses his VFD as a "Wall Wart converter" Always set to 60/50 hz. Not taking advantage of the variable frequency function at all.


Probably me! I have a Teco 10 Hp rated digital box with inline choke / reactor units supplied as an effective replacement for a proper 440 V three phase supply as in being able to run a workshop ring main for machines using their original contactor controls. (In the UK electromagnetic NVR and overload protected switch-gear are standard on three phase machines. Direct manual switching being pretty much unheard of outside the realms of extreme bodgery and antiques.)

However there are significant limitations. Firstly the VFR box has to have considerable short term overload capacity to handle the starting surges. Without looking at the book I think mine is rated around 200 to 300% overload for 30 seconds. Secondly its not advised to use motors larger than around half the VFD rated output power although this is something of a moveable feast depending on whether the motor starts free running or under load. Running 10 HP worth of motors is no problem, its just the start surge. Given the reactive nature of the in line chokes I treat this as a fixed frequency set-up but I suspect that some exploitation of the VFD capability would be allowable on a single motor.

I wouldn't care to be more ambitious than simple motor start stop applications.

Clive

 

[Burdekin]

For info, reply from Dave at Direct Drives. It's not a cheap option but if you don't have 3ph and have multiple machines in your workshop then looks like a doable option.

HI,

well when using an inverter in plug and play mode you need to allow for starting surge,

Our model MA10SYS is designed for this application and costs £1500+VAT, this has input RFI, and SINE filters and BOOST packs and run a machine up to 2.2KW single motor start and total load up to 10HP, it gives out 3 phase and earth so if your machine only needs 3 phase plus earth then it will run it even if there is a DRO fitted BUT if the machine needs a neutral supply its best to run the DRO off a 240V supply as that saves money on having a neutral generator at £195,

The output of this you can take around the workshop and run all items up to 3HP in Plug and play but you can direct run up to a 7.5HP machine like a Colchester 2000 for example if you order the SS option at £50, with this you can switch between one BIG machine in direct connection with soft start or rest of the workshop in Plug and Play mode,

 

[armalites]

Thanks, that's useful info that I wasn't aware of.

The things that you can do with them is amazing once you get deep into the manual.

I have one running a 4-post ramp and I did have it on a tyre changer for a while and changing the ramp up and down settings made quite a difference to the way things worked.

I have looked at changing the motor on my old Myford for 3ph with inverter so I can control speed etc.

The one I have is an IMO and has been very reliable given that it is in an open barn although covered(with an old feed bag )

 

[Burdekin]

Yep, good to have a few options. I need to discuss this with my electrician as it's getting expensive. Some specs and more info that they just sent me:

Specifications
Input Voltage :- 240 Volts AC Single Phase @ 50Hz
Input Current :- 50 Amps at full output load
Input MCB specification :- 50 Amps type ‘C’ MCB
Output Voltage :- 415 Volts 3 phase @ 50Hz & earth
Output Loading :- 16 Amps per phase @ 415 Volts across phases
Output Capacity :- 12 KVA
Output NEUTRAL Loading :- option of 5 amps @ 230 Volts any phase to neutral
Protection :- IP 20 - Fixed Application
EMC :- EN 61800-3
Operation Temperature :- -10 to 50 DegC


The MA-10 SYS phase converter system is designed to convert a 240 Volts SINGLE PHASE supply into a 415 Volts 3 Phase supply to power industrial equipment, It is designed for a fixed application where the phase converter is an integral part of the customers power system,
The INPUT supply is connected to the unit via an umbilical cord conduit that contains 2 black 16mm cables for the 240 Volts supply and a GREEN/YELLOW EARTH wire, the black cables are marked to identify the LINE and NEUTRAL and if the unit is running at FULL LOAD 50 Amps would be drawn from the 240 Volts input,
This circuit requires over current protection via a 50 Amp type ‘C’ MCB,
The system is normally set to AUTO START after power is applied,

 

[hareng]

Burdeken that wont be man enough, been there done it wasted £650, blew up in less than 1 1/2hrs. Still waiting for dosh off your intended supplier almost two years on no wonder they both drive two massive 4x4's of quality.

You would need the 7.5KW 10HP Plug and play to start that M300 at 400V £1100. Exactly what i use and can power anything 3ph 440v up, just plug it in as if in a factory.
My mate runs a newer Student and a Bridgy off one, direct as intended.
Need a decent 240V feed.
When power inverter on no need for soft start else the relays sound like chattering in control panel, you would still have the hard start.

Same applies to other machines in workshop, no need to rewire just plug machine in and run it as intended.

If only one machine its probably worthwhile going the VFD route, wish i had done it but incorrectly advised by your intended supplier. I would need a new dual voltage motor to do so as well still far cheaper than a 400V output plug and play that blew! If not electrically minded it could cost a bit for a sparky to wire up and figure the functions with trails of cables to inverter.
You would need an inverter for each machine and rework the switches etc and still have probs with coolant pumps.

 

[Burdekin]

Burdeken that wont be man enough, been there done it wasted £650, blew up in less than 1 1/2hrs. Still waiting for dosh off your intended supplier almost two years on no wonder they both drive two massive 4x4's of quality.

You would need the 7.5KW 10HP Plug and play to start that M300 at 400V £1100. Exactly what i use and can power anything 3ph 440v up, just plug it in as if in a factory.
My mate runs a newer Student and a Bridgy off one, direct as intended.
Need a decent 240V feed.
When power inverter on no need for soft start else the relays sound like chattering in control panel, you would still have the hard start.

Same applies to other machines in workshop, no need to rewire just plug machine in and run it as intended.

If only one machine its probably worthwhile going the VFD route, wish i had done it but incorrectly advised by your intended supplier. I would need a new dual voltage motor to do so as well still far cheaper than a 400V output plug and play that blew! If not electrically minded it could cost a bit for a sparky to wire up and figure the functions with trails of cables to inverter.
You would need an inverter for each machine and rework the switches etc and still have probs with coolant pumps.

Thanks.

Just going to go for the single 3hp VFD conversion and when I get a milling machine I will just do the same for it. I suppose for the coolant pump it's probably best just to put in a single phase motor. I'll start having a play tomorrow night when I'm home.

 

[hareng]

These are supposed to give superb customer service, wish i found these a few years ago.
http://www.newton-tesla.co.uk/
Mitsubishi far better http://www.ebay.co.uk/itm/3-0HP-2-2...ial_Automation_Control_ET&hash=item4d08ba5007

 

[Burdekin]

Thanks for the info and links.