Startrite 18-s-5. 3 phase dilemma

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2121marty

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So I’m at it again, sneaky afternoon dash over the border into Wales to pick up a Startrite 18-s-5 bandsaw. Right sort of money taking into account it’s a little unloved a not a 240v version.
It is a 3 phase machine, but I don’t have 3 phase so I was after a little advice on the best route to go down. This forum was so helpful sorting out my t/a saw so I thought this would be the best place to ask. I have a new 20amp feed into the workshop.
The guy I purchased it from made his own converter, he has a background in that sort of thing apparently but I was a little less than convinced by his set up not to mention confused. He has added to the original wiring in the side hatch and mentioned something about removing a contactor.
So my understanding is I can either…

run it off a trans wave converter? (Reinstating correct original wiring)
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VFD whatever the hell they are?

Or convert to 240v?

any help and advice appreciated.
 

Ttrees

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If you can't or don't want to get a single phase motor,
it might be worth looking under the terminal cover/lid of the motor to see if the
motor is dual voltage or fixed star wound, as the latter would be more involved or more expensive should you go the VFD/inverter route
(less than a hundred "all in" should it actually be a dual voltage motor, and you can find/lash up a suitable metal box for the unit)
There might be schematics on the lid for star/delta voltage configuration.

There is also digital phase converters, member Deema has wrote some posts about this,
should you wish to amass a multitude of 3 phase machinery.
I believe these are more efficient than either static or rotary phase converters.
Myfordman/Bob ( 9fingers on "the other place" )
has the PDF about all this, and I've not seen anything near as good of a read.

I suggest you find this should you wish to know more about what you are looking for,
ie going single phase route, frame size, RPM, switches and all that, to find a suitable replacement,
or go the inverter route if easier, as you need to have knowledge of some basic principals like speed, as a VFD/inverter is basically the brain of a motor and needs programming to suit, since an induction motor is not a high speed spindle for CNC's.

ps had to correct myself once already, so worth noting that the PDF is worth reading!
and pp*, beware of some youtubes on the matter, not waiting for the unit to drain off the lethal charge before going near the main wires, Bob explains all this.

Good luck
Tom
 
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2121marty

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If you can't or don't want to get a single phase motor,
it might be worth looking under the terminal cover/lid of the motor to see if the
motor is dual voltage or fixed star wound, as the latter would be more involved or more expensive should you go the VFD/inverter route
(less than a hundred "all in" should it actually be a dual voltage motor, and you can find/lash up a suitable metal box for the unit)
There might be schematics on the lid for star/delta voltage configuration.

There is also digital phase converters, member Deema has wrote some posts about this,
should you wish to amass a multitude of 3 phase machinery.
I believe these are more efficient than either static or rotary phase converters.
Myfordman/Bob ( 9fingers on "the other place" )
has the PDF about all this, and I've not seen anything near as good of a read.

I suggest you find this should you wish to know more about what you are looking for,
ie going single phase route, frame size, RPM, switches and all that, to find a suitable replacement,
or go the inverter route if easier, as you need to have knowledge of some basic principals like speed, as a VFD/inverter is basically the brain of a motor and needs programming to suit, since an induction motor is not a high speed spindle for CNC's.

ps had to correct myself once already, so worth noting that the PDF is worth reading!
and pp*, beware of some youtubes on the matter, not waiting for the unit to drain off the lethal charge before going near the main wires, Bob explains all this.

Good luck
Tom
The seller mention something about dual voltage he said he changed wiring on the top of the motor and I would need to change it back?, he separated the 3 wires or put the 3 together I can’t quite remember I’ll have to check.
I have no understanding of electrics I’m afraid and there seems a rubbish load of wiring inside the panel for 1 input a motor and a switch…must be an easier way?
 

Gordon Tarling

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If you have no understanding of electrics, then best to get a professsional to look at it and do the work, for the sake of safety and peace of mind.

G.
 

deema

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Nice saw, good buy. I suspect that the motor is a dedicated 440V, which was typical for this vintage power rating in my experience of tinkering with machines. You can probably dig out the star point to make it delta, but you need to know what you are doing, and by asking the questions you are……don’t do it.
The motor is probably imperial, in other words has a shaft that is probably 5/8” diameter rather than a modern metric size. New motors can be bought that are imperial, but are extremely expensive. The pulley is cast and hasn’t enough meet in it usually to bore out to metric size and you’d need to add a key way. You can of course turn and mill the motor shaft down, but most woodworkers don’t have access to these machines.
The best solution is a digital phase converter, it’s also probably the cheapest solution. Unless your comfortable and trained in electrics get a professional industrial (not domestic) electrician to sort you out and install it.
 

Spectric

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Two options, change the motor to a single phase one which should not be difficult or buy a digital phase convertor which will provide a fixed frequency 400 volt three phase supply and means you don't need to change anything on the machine, plus you could have multiple machines connected provided the convertor has the power available.

Personally I would just change the motor, they are not expensive and you may have to change the starter (DOL) if the coil in it is 400 volt but it could be 230 volt even on three phase if the machine has a neutral.
 

guineafowl21

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The motor plate indicates that it’s a dual voltage type, and since it’s only 900W so your best bet is a 1.5 kW VFD.

The connections inside the motor will need to be changed from star back to delta, by the sounds of it. See Bob’s PDF.
 

deema

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@guineafowl21, my bad, I didn’t read it properly! Your right. I’m which case a VFD could be used, again industrial electrician to install.
Id fit either a 5.5 or a 7KW phase inverter, so I could run just about any 3 phase machine without any electrical changes to any future machines I bought. The price won’t be that much more than a VFD which would be dedicated to a single machine and need the machines electrics altering.
 

Myfordman

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No it is not dual voltage in the sense of star delta changeover. It is simply designed to use over the range 380 -440 volts.
The vendor may have opened up the star point in which case there will be 6 connections not 3
 

guineafowl21

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No it is not dual voltage in the sense of star delta changeover. It is simply designed to use over the range 380 -440 volts.
The vendor may have opened up the star point in which case there will be 6 connections not 3
Bob, with respect I think it is - below the 380/440 line there is another that states 220/250, and the corresponding amps.
 

deema

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Makes me feel better that I wasn’t the only one to miss the second part of the label.
 

2121marty

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@guineafowl21, my bad, I didn’t read it properly! Your right. I’m which case a VFD could be used, again industrial electrician to install.
Id fit either a 5.5 or a 7KW phase inverter, so I could run just about any 3 phase machine without any electrical changes to any future machines I bought. The price won’t be that much more than a VFD which would be dedicated to a single machine and need the machines electrics altering.
Inverter?, is that different to a phase converter and a VFD is different again so is that 3 different things?, sorry it’s a little over my head…😬
Rest assured I will find someone qualified to do the work only I’d like to have the correct/safest option purchased and waiting for installation rather than whatever was on the van🤣
I am still looking for a morticer and spindle moulder so I may end up with other 3 phase machines. Thanks
 

deema

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If you are going to have a spindle moulder, and suspect it will be 3ph, then get a digital phase converter (DPC). You can use it to power up any 3ph machine……with a few caveats. For large masses that are being turned and that may include the spindle DPC typically need to be larger than the load. So, a 4KW spindle may need a 7KW DPC. This is not a rotary phase converter or a static phase converter. Its a box that allows you to speed control anything that is connected to it as well as changing domestic single phase into 3ph. It can also like a VFD break the motor to make to PUWER compliant. They can run multiple machimes at the sametime as long as you don’t exceed their power rating. You can get 15KW units.
 

Myfordman

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Bob, with respect I think it is - below the 380/440 line there is another that states 220/250, and the corresponding amps.
Yes you are correct. I stand corrected
If the op ever want to cut metal then a combination of the 5 speed gearbox and an inverter would be ideal

Otherwise possibly a motor swap but it would have to be an imperial one for the pulley to fit. Easy for the mechanically adept to adapt a metric motor but maybe not so in this case.
Imperial motors new tend to be expensive but used one could be had much cheaper


Bob
 

Spectric

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Inverter?, is that different to a phase converter and a VFD is different again so is that 3 different things?,
There are two main options, An invertor is limited in the max load you can use, can only run one machine but can offer variable speed and is also known as a VFD. The digital phase convertor can supply larger loads, only restricted by your electrical supply and can run multiple machines but fixed frequency, hence fixed speed but you get 400 volts so no machine mods.

Invertor is Ac to Dc to Ac whereas the convertor replicates the missing phase digitally.
 

Ttrees

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Seems like from what the above highly knowledgeable lads are saying...
Is that it is possibly a dual voltage motor?
If so, and yer skint, then the VFD/inverter route could likely be the way to go, should there not be some other wizardry which is involved, which is waaay over my head.

Just sayin from a Joe Soap's perspective who hasn't done more than wire a plug,
hooking up a VFD (for a bandsaw or tablesaw) involves 7 wires at its most basic level, and provided you can program it,
That is enough to get it working, you can add an on/off switch afterwards, so fairly easy.
Depending on whether you can mount the drive inside the column of the bandsaw,
or make a box, five folds of sheet metal screw or rivet together a back and hinged lid,
partly recycle an old exit sign, washing machine or what have you.
You could do that while reading through Bob's induction motor PDF
(not allowed to give you a link here to "the other place")

This treatise is wrote for someone exactly in your shoes, who's faced with these options of going with single phase motor, getting a VFD or otherwise.
Best thing I've ever read on the matter!

All the best
Tom
 

2121marty

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Seems like from what the above highly knowledgeable lads are saying...
Is that it is possibly a dual voltage motor?
If so, and yer skint, then the VFD/inverter route could likely be the way to go, should there not be some other wizardry which is involved, which is waaay over my head.

Just sayin from a Joe Soap's perspective who hasn't done more than wire a plug,
hooking up a VFD (for a bandsaw or tablesaw) involves 7 wires at its most basic level, and provided you can program it,
That is enough to get it working, you can add an on/off switch afterwards, so fairly easy.
Depending on whether you can mount the drive inside the column of the bandsaw,
or make a box, five folds of sheet metal screw or rivet together a back and hinged lid,
partly recycle an old exit sign, washing machine or what have you.
You could do that while reading through Bob's induction motor PDF
(not allowed to give you a link here to "the other place")

This treatise is wrote for someone exactly in your shoes, who's faced with these options of going with single phase motor, getting a VFD or otherwise.
Best thing I've ever read on the matter!

All the best
Tom
Cheers Tom, I have only ever used this forum so I’ll have to do some google investigation as to what ‘the other place’ is…appreciate the help and direction.
 
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