The 3 phase cable I have that's still connected up to this rather large lathe I bought has some unfamiliar colours making it up. There's a braided shield round the outside which I assume is for grounding purposes. Then four equal thickness conductors inside: brown, grey, black and blue. I have to somehow marry these up to the inverter box where the appropriate terminals are marked 'U','V' & 'W' which is neither helpful nor meaningful to me. Can anyone clue me up here? I'm starting to develop a complex over all the flashes and bangs I've experienced recently. Don't want to end up a nervous wreck. Thanks.

wrote:
The 3 phase cable I have that's still connected up to this rather
large lathe I bought has some unfamiliar colours making it up.
There's a braided shield round the outside which I assume is for
grounding purposes. Then four equal thickness conductors inside:
brown, grey, black and blue. I have to somehow marry these up to the
inverter box where the appropriate terminals are marked 'U','V' & 'W'
which is neither helpful nor meaningful to me. Can anyone clue me up
here? I'm starting to develop a complex over all the flashes and
bangs I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black and grey are
the phase wires (U,V &W) the blue is probably used an earth.

You need to look inside the lathe to confirm this.

--
Adam

On 04/08/2013 15:20, wrote:

The 3 phase cable I have that's still connected up to this rather
large lathe I bought has some unfamiliar colours making it up.
There's a braided shield round the outside which I assume is for
grounding purposes. Then four equal thickness conductors inside:
brown, grey, black and blue. I have to somehow marry these up to the

Those are the "normal" 3ph colours now:

http://wiki.diyfaq.org.uk/index.php?...armo nisation

would have been red/blue/yellow and black in the past.

inverter box where the appropriate terminals are marked 'U','V' & 'W'
which is neither helpful nor meaningful to me. Can anyone clue me up
here? I'm starting to develop a complex over all the flashes and
bangs I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

Sounds like the lathe has connection for the three phases, but no neutral.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sunday, 4 August 2013 16:41:28 UTC+2, John Rumm wrote:
On 04/08/2013 15:20, wrote:



The 3 phase cable I have that's still connected up to this rather

large lathe I bought has some unfamiliar colours making it up.

There's a braided shield round the outside which I assume is for

grounding purposes. Then four equal thickness conductors inside:

brown, grey, black and blue. I have to somehow marry these up to the



Those are the "normal" 3ph colours now:



http://wiki.diyfaq.org.uk/index.php?...armo nisation



would have been red/blue/yellow and black in the past.



inverter box where the appropriate terminals are marked 'U','V' & 'W'

which is neither helpful nor meaningful to me. Can anyone clue me up

here? I'm starting to develop a complex over all the flashes and

bangs I've experienced recently. Don't want to end up a nervous

wreck. Thanks.



Sounds like the lathe has connection for the three phases, but no neutral.



--

Cheers,



John.



/================================================== ===============\

| Internode Ltd - http://www.internode.co.uk |

|-----------------------------------------------------------------|

| John Rumm - john(at)internode(dot)co(dot)uk |

\================================================= ================/

Yeah, I need to change the lathe motor box from star to delta and IIRC, delta doesn't use the neutral.

"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this rather
large lathe I bought has some unfamiliar colours making it up.
There's a braided shield round the outside which I assume is for
grounding purposes. Then four equal thickness conductors inside:
brown, grey, black and blue. I have to somehow marry these up to the
inverter box where the appropriate terminals are marked 'U','V' & 'W'
which is neither helpful nor meaningful to me. Can anyone clue me up
here? I'm starting to develop a complex over all the flashes and
bangs I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black and grey
are the phase wires (U,V &W) the blue is probably used an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the CPC/Earth
conductor being the braid that he refers to ? Many machine tools bring in a
neutral to allow 240v contactors, lights and the like.

AWEM

Andrew Mawson wrote:
"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this rather
large lathe I bought has some unfamiliar colours making it up.
There's a braided shield round the outside which I assume is for
grounding purposes. Then four equal thickness conductors inside:
brown, grey, black and blue. I have to somehow marry these up to the
inverter box where the appropriate terminals are marked 'U','V' &
'W' which is neither helpful nor meaningful to me. Can anyone clue
me up here? I'm starting to develop a complex over all the flashes
and bangs I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black and
grey are the phase wires (U,V &W) the blue is probably used an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the CPC/Earth
conductor being the braid that he refers to ? Many machine tools
bring in a neutral to allow 240v contactors, lights and the like.

I did ask the OP to confirm this.

I have seen many more 3 phase only machines than 3 phase and neutral
machines.

--
Adam

ARW wrote:
Andrew Mawson wrote:
"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this rather
large lathe I bought has some unfamiliar colours making it up.
There's a braided shield round the outside which I assume is for
grounding purposes. Then four equal thickness conductors inside:
brown, grey, black and blue. I have to somehow marry these up to the
inverter box where the appropriate terminals are marked 'U','V' &
'W' which is neither helpful nor meaningful to me. Can anyone clue
me up here? I'm starting to develop a complex over all the flashes
and bangs I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black and
grey are the phase wires (U,V &W) the blue is probably used an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the CPC/Earth
conductor being the braid that he refers to ? Many machine tools
bring in a neutral to allow 240v contactors, lights and the like.

I did ask the OP to confirm this.

I have seen many more 3 phase only machines than 3 phase and neutral
machines.

CY cable that I've used is either 4 core - 3 phases + earth + braid or 5
core 3 phases, neutral earth plus braid.

The theory is the the earth must be used for earth continuity to the
motor but the braid should only be connected at the inverter end so it
can act as a true RF shield to minimise the crap from the inverter
interfering with other equipment. If any current passes down the braid
(however small) the braid itself turns into an antenna and radiates the
RF energy.

Bob

On 04/08/2013 16:44, ARW wrote:
Andrew Mawson wrote:
"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this
rather large lathe I bought has some unfamiliar colours making
it up. There's a braided shield round the outside which I
assume is for grounding purposes. Then four equal thickness
conductors inside: brown, grey, black and blue. I have to
somehow marry these up to the inverter box where the
appropriate terminals are marked 'U','V' & 'W' which is neither
helpful nor meaningful to me. Can anyone clue me up here? I'm
starting to develop a complex over all the flashes and bangs
I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black
and grey are the phase wires (U,V &W) the blue is probably used
an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the
CPC/Earth conductor being the braid that he refers to ? Many
machine tools bring in a neutral to allow 240v contactors, lights
and the like.

I did ask the OP to confirm this.

I have seen many more 3 phase only machines than 3 phase and neutral
machines.


I agree it's best for the OP to confirm, but aren't the harmonised
colours for the phases: Brown, Black and Grey, with Blue for Neutral?

The Armour/braid being the CPC?

Fredxx wrote:
On 04/08/2013 16:44, ARW wrote:
Andrew Mawson wrote:
"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this
rather large lathe I bought has some unfamiliar colours making
it up. There's a braided shield round the outside which I
assume is for grounding purposes. Then four equal thickness
conductors inside: brown, grey, black and blue. I have to
somehow marry these up to the inverter box where the
appropriate terminals are marked 'U','V' & 'W' which is neither
helpful nor meaningful to me. Can anyone clue me up here? I'm
starting to develop a complex over all the flashes and bangs
I've experienced recently. Don't want to end up a nervous
wreck. Thanks.

I do not think there is as lot to worry about. The brown, black
and grey are the phase wires (U,V &W) the blue is probably used
an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the
CPC/Earth conductor being the braid that he refers to ? Many
machine tools bring in a neutral to allow 240v contactors, lights
and the like.

I did ask the OP to confirm this.

I have seen many more 3 phase only machines than 3 phase and neutral
machines.


I agree it's best for the OP to confirm, but aren't the harmonised
colours for the phases: Brown, Black and Grey, with Blue for Neutral?

The Armour/braid being the CPC?

Yes, that is correct.

However what I am saying is that the number of times I have seen 4 core SWA
used on a 3 phase supply with the 4th core used as a cpc and not as a
neutral far outweighs the number of times I have seen the 4th core used as a
neutral.

--
Adam

On 04/08/2013 15:44, wrote:
On Sunday, 4 August 2013 16:41:28 UTC+2, John Rumm wrote:
On 04/08/2013 15:20, wrote:

Sounds like the lathe has connection for the three phases, but no
neutral.

Yeah, I need to change the lathe motor box from star to delta and
IIRC, delta doesn't use the neutral.

Don't think you *have* to use it in star config either.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 04/08/2013 15:44, wrote:
On Sunday, 4 August 2013 16:41:28 UTC+2, John Rumm wrote:
On 04/08/2013 15:20, wrote:

Sounds like the lathe has connection for the three phases, but no
neutral.

Yeah, I need to change the lathe motor box from star to delta and
IIRC, delta doesn't use the neutral.

Don't think you *have* to use it in star config either.

Most Star -Delta starters have no Magnolia/Swizterland.

--
Adam

On 04/08/2013 18:02, ARW wrote:
Fredxx wrote:
On 04/08/2013 16:44, ARW wrote:
Andrew Mawson wrote:
"ARW" wrote in message ...

wrote:
The 3 phase cable I have that's still connected up to this
rather large lathe I bought has some unfamiliar colours
making it up. There's a braided shield round the outside
which I assume is for grounding purposes. Then four equal
thickness conductors inside: brown, grey, black and blue. I
have to somehow marry these up to the inverter box where
the appropriate terminals are marked 'U','V' & 'W' which is
neither helpful nor meaningful to me. Can anyone clue me up
here? I'm starting to develop a complex over all the
flashes and bangs I've experienced recently. Don't want to
end up a nervous wreck. Thanks.

I do not think there is as lot to worry about. The brown,
black and grey are the phase wires (U,V &W) the blue is
probably used an earth.

You need to look inside the lathe to confirm this.



Surely Adam the Blue is more likely to be Neutral, with the
CPC/Earth conductor being the braid that he refers to ? Many
machine tools bring in a neutral to allow 240v contactors,
lights and the like.

I did ask the OP to confirm this.

I have seen many more 3 phase only machines than 3 phase and
neutral machines.


I agree it's best for the OP to confirm, but aren't the harmonised
colours for the phases: Brown, Black and Grey, with Blue for
Neutral?

The Armour/braid being the CPC?

Yes, that is correct.

However what I am saying is that the number of times I have seen 4
core SWA used on a 3 phase supply with the 4th core used as a cpc and
not as a neutral far outweighs the number of times I have seen the
4th core used as a neutral.

I bow to your knowledge. However the core, if non green/yellow, should
have a sleeve indicating CPC.

Of course should easy to check on the machine.

So basically you're saying I can just connect *any* phase wire up to the u, v or w and the order doesn't matter? I mean I don't need to specifically connect a certain colour to a certain lettered connector?

wrote:

So basically you're saying I can just connect *any* phase wire up to
the u, v or w and the order doesn't matter?

Depends if direction matters, if it spins the wrong way swap any two
wires, if your 3ph converter can reverse direction, even easier.

wrote in message
...

So basically you're saying I can just connect *any* phase wire up to the u,
v or w and the order doesn't matter? I mean I don't need to specifically
connect a certain colour to a certain lettered connector?

So long as you don't mind which way the motors revolve then yes. However if
you are running off a static phase converter you need to ensure that your
contactor coils are driven by a phase other than the generated phase.

AWEM

Reference the Star-delta question, are you sure that the motor is modern enough to have all the coil ends brought out so that you can change configuration. Most electronic inverters - at least the less expensive ones - are 240vac 3ph output rather than the 410vac required for star.

Older motors are hard wired for star as I discovered on a friend's Graduate lathe for which I recommended an inverter, and then had to dismantle the motor to reconnect the coils.

Rob

On Sun, 04 Aug 2013 11:30:23 -0700, orion.osiris wrote:

So basically you're saying I can just connect *any* phase wire up to the
u, v or w and the order doesn't matter? I mean I don't need to
specifically connect a certain colour to a certain lettered connector?


First. Look in the terminal box at the lathe end of the cable. What are
the terminal markings in there, and which cable colours are connected to
them?

Usually:
Phase 1 is L1 / Red / U / R / Brown
Phase 2 is L2 / Yellow or white / V / S / Black
Phase 3 is L3 / Blue / W / T / Grey
Neutral is N / Black / N / N / Blue

Although variations exist.

If a neutral connection is used for the lathe then you will need to
source it from the inverter somehow (or make some other arrangement) as
it will be used for the control circuit. You can't omit it. Even if the
motor is star connected the neutral may not be connected to the star
point of the winding (that is very unusual).

As others have said, if you reverse any 2 phases of a 3-phase motor it
will run in reverse. So no, you don't have to be specific in colours &
markings. If the lathe was properly installed then it will probably have
been connected as one of the above sequences.

Unless the lathe was originally fed from an inverter or speed controller
it will almost certainly be using the braid as protective earth. The blue
(usually neutral for brown/black/grey/blue cable) wire may or may not be
connected. You MUST check. You also MUST check whether the braid is used
as protective earth and make sure that it is terminated correctly at both
ends if it is.

wrote in message
...
On Sunday, 4 August 2013 16:41:28 UTC+2, John Rumm wrote:
On 04/08/2013 15:20, wrote:



The 3 phase cable I have that's still connected up to this rather

large lathe I bought has some unfamiliar colours making it up.

There's a braided shield round the outside which I assume is for

grounding purposes. Then four equal thickness conductors inside:

brown, grey, black and blue. I have to somehow marry these up to the



Those are the "normal" 3ph colours now:



http://wiki.diyfaq.org.uk/index.php?...armo nisation



would have been red/blue/yellow and black in the past.



inverter box where the appropriate terminals are marked 'U','V' & 'W'

which is neither helpful nor meaningful to me. Can anyone clue me up

here? I'm starting to develop a complex over all the flashes and

bangs I've experienced recently. Don't want to end up a nervous

wreck. Thanks.



Sounds like the lathe has connection for the three phases, but no
neutral.



--

Cheers,



John.



/================================================== ===============\

| Internode Ltd - http://www.internode.co.uk |

|-----------------------------------------------------------------|

| John Rumm - john(at)internode(dot)co(dot)uk |

\================================================= ================/

Yeah, I need to change the lathe motor box from star to delta and IIRC,
delta doesn't use the neutral.
It depends if it is a dual voltage motor.

If it is dual voltage it will be delta for 220 volt (Phase/phase) and star
for 400 volts (phase /phase).
There is not much requirement for this sort of thing now, as we and the EU
are similar voltages.

The neutrel is not needed for the motor iself but may be needed for
ancilliaries.
If it is a dual voltage motor & starter, the starter coil will be the low
voltage so you would need a neutral if is were run in high voltage
configuration.

On Sunday, 4 August 2013 21:04:09 UTC+2, robgraham wrote:
Reference the Star-delta question, are you sure that the motor is modern enough to have all the coil ends brought out so that you can change configuration. Most electronic inverters - at least the less expensive ones - are 240vac 3ph output rather than the 410vac required for star.

Older motors are hard wired for star as I discovered on a friend's Graduate lathe for which I recommended an inverter, and then had to dismantle the motor to reconnect the coils.

The motor is 1998 manufactured and dual voltage 230/415 3 phase 3hp/2.2kw according to the plate on it. My converter puts out 230V 3 phase from a 230V single phase input supply.
There appears to be a box mounted atop the motor where the delta/star connections can be changed. I say "appears" because it looks like it's going to be a devil of a job to get the lid off and I can't say for sure until I do, but we'll find out eventually by which time I'll no doubt have shed yet more grey hairs.

On Sunday, 4 August 2013 21:40:56 UTC+2, mick wrote:
On Sun, 04 Aug 2013 11:30:23 -0700, orion.osiris wrote:



So basically you're saying I can just connect *any* phase wire up to the

u, v or w and the order doesn't matter? I mean I don't need to

specifically connect a certain colour to a certain lettered connector?





First. Look in the terminal box at the lathe end of the cable. What are

the terminal markings in there, and which cable colours are connected to

them?



Usually:

Phase 1 is L1 / Red / U / R / Brown

Phase 2 is L2 / Yellow or white / V / S / Black

Phase 3 is L3 / Blue / W / T / Grey

Neutral is N / Black / N / N / Blue



Although variations exist.



If a neutral connection is used for the lathe then you will need to

source it from the inverter somehow (or make some other arrangement) as

it will be used for the control circuit. You can't omit it. Even if the

motor is star connected the neutral may not be connected to the star

point of the winding (that is very unusual).



As others have said, if you reverse any 2 phases of a 3-phase motor it

will run in reverse. So no, you don't have to be specific in colours &

markings. If the lathe was properly installed then it will probably have

been connected as one of the above sequences.



Unless the lathe was originally fed from an inverter or speed controller

it will almost certainly be using the braid as protective earth. The blue

(usually neutral for brown/black/grey/blue cable) wire may or may not be

connected. You MUST check. You also MUST check whether the braid is used

as protective earth and make sure that it is terminated correctly at both

ends if it is.

THanks, Mick. I was wondering if I should make the addition of an earth spike within the workshop itself to be on the safe side, since there is a run of about 10 meters from the lathe back to the existing earth in the house's distribution board. Any thoughts on the advisability of that and if so, are those cheaper, copper plated spikes good enuff for the job?
Come to think of it, I've got some 15mm copper pipe laying around that would probably do just as well as a spike...

On 04/08/2013 20:40, mick wrote:
....
First. Look in the terminal box at the lathe end of the cable. What are
the terminal markings in there, and which cable colours are connected to
them?

Usually:
Phase 1 is L1 / Red / U / R / Brown
Phase 2 is L2 / Yellow or white / V / S / Black
Phase 3 is L3 / Blue / W / T / Grey
Neutral is N / Black / N / N / Blue

Although variations exist.

Most three phase machines I worked with came with three red wires and,
sometimes, one black.

....
As others have said, if you reverse any 2 phases of a 3-phase motor it
will run in reverse....

I think there is some natural law that they will always run the wrong
way when you first connect them, ;-)

Colin Bignell

On Mon, 05 Aug 2013 09:09:11 +0100
Nightjar wrote:

On 04/08/2013 20:40, mick wrote:
...
First. Look in the terminal box at the lathe end of the cable. What
are the terminal markings in there, and which cable colours are
connected to them?

Usually:
Phase 1 is L1 / Red / U / R / Brown
Phase 2 is L2 / Yellow or white / V / S / Black
Phase 3 is L3 / Blue / W / T / Grey
Neutral is N / Black / N / N / Blue

Although variations exist.

Most three phase machines I worked with came with three red wires
and, sometimes, one black.

...
As others have said, if you reverse any 2 phases of a 3-phase motor
it will run in reverse....

I think there is some natural law that they will always run the wrong
way when you first connect them, ;-)

Colin Bignell


I know there is some natural law that they will always run the wrong
way when you first connect them. Especially if it matters.
--
Davey.

On Tuesday, 6 August 2013 01:58:05 UTC+2, Davey wrote:
On Mon, 05 Aug 2013 09:09:11 +0100

Nightjar wrote:



On 04/08/2013 20:40, mick wrote:

...

First. Look in the terminal box at the lathe end of the cable. What

are the terminal markings in there, and which cable colours are

connected to them?



Usually:

Phase 1 is L1 / Red / U / R / Brown

Phase 2 is L2 / Yellow or white / V / S / Black

Phase 3 is L3 / Blue / W / T / Grey

Neutral is N / Black / N / N / Blue



Although variations exist.



Most three phase machines I worked with came with three red wires

and, sometimes, one black.



...

As others have said, if you reverse any 2 phases of a 3-phase motor

it will run in reverse....



I think there is some natural law that they will always run the wrong

way when you first connect them, ;-)



Colin Bignell





I know there is some natural law that they will always run the wrong

way when you first connect them. Especially if it matters.

--

Davey.

After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.

On 06/08/2013 13:56, wrote:
....
After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.


The lack of follow-up postings to tell us all went well is slightly
worrying.

Colin Bignell

On Thu, 08 Aug 2013 09:56:43 +0100
Nightjar wrote:

On 06/08/2013 13:56, wrote:
...
After about 2 hours struggling, I finally managed to get enough
clearance under the motor box lid to swap the config over from star
to delta. So am now looking at the Big Switch On sometime this
afternoon and hoping for zero explosions or flashes/bangs as I
don't think my nerves can stand it.


The lack of follow-up postings to tell us all went well is slightly
worrying.

Colin Bignell

Any big flashes seen recently, other than lightning?
--
Davey.

On Thursday, August 8, 2013 10:56:43 AM UTC+2, Nightjar wrote:
On 06/08/2013 13:56, wrote:

...

After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.





The lack of follow-up postings to tell us all went well is slightly

worrying.

Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothing happened. Nothing at all. Completely dead.
Having done a bit of research on the net, it seems one has to connect the output of the converter direct to the motor. I'd actually connected it to the lathe's existing 3 phase cable which goes off into a complex switchbox expecting 415 Volts. The converter's output is 3 phase alright, but at only 230V. Obvious in retrospect, but an easy error to make at the time.
Unfortunately there's a so-called 'suds' motor which powers the coolant pump and it requires 400V. If that turns out to be dual voltage too, then I could connect it up delta and power it from the converter, but then the coolant rate will vary in tune with the main motor speed control provided by the converter!
It might be simpler to swap the suds motor for a 230v one.

On Thursday, August 8, 2013 10:56:43 AM UTC+2, Nightjar wrote:
On 06/08/2013 13:56, wrote:

...

After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.





The lack of follow-up postings to tell us all went well is slightly

worrying.

Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothing happened. Nothing at all. Completely dead.
Having done a bit of research on the net, it seems one has to connect the output of the converter direct to the motor. I'd actually connected it to the lathe's existing 3 phase cable which goes off into a complex switchbox expecting 415 Volts. The converter's output is 3 phase alright, but at only 230V. Obvious in retrospect, but an easy error to make at the time.
Unfortunately there's a so-called 'suds' motor which powers the coolant pump and it requires 400V. If that turns out to be dual voltage too, then I could connect it up delta and power it from the converter, but then the coolant rate will vary in tune with the main motor speed control provided by the converter!
It might be simpler to swap the suds motor for a 230v one and just run it off a 13A socket.

On 08/08/2013 13:50, wrote:
On Thursday, August 8, 2013 10:56:43 AM UTC+2, Nightjar wrote:
On 06/08/2013 13:56, wrote:

...

After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.





The lack of follow-up postings to tell us all went well is slightly

worrying.

Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothing happened. Nothing at all. Completely dead.

At least you are still with us :-)

Having done a bit of research on the net, it seems one has to connect the output of the converter direct to the motor. I'd actually connected it to the lathe's existing 3 phase cable which goes off into a complex switchbox expecting 415 Volts. The converter's output is 3 phase alright, but at only 230V. Obvious in retrospect, but an easy error to make at the time.
Unfortunately there's a so-called 'suds' motor which powers the coolant pump and it requires 400V. If that turns out to be dual voltage too, then I could connect it up delta and power it from the converter, but then the coolant rate will vary in tune with the main motor speed control provided by the converter!
It might be simpler to swap the suds motor for a 230v one.

They are cheap enough, assuming you don't have one like I had in a tool
and cutter grinding machine. The motor casing was part of the machine
casting and, when the motor failed, the only option (the manufacturer
being long gone) was to send the entire machine away to have the motor
re-wound.

Colin Bignell

On Thursday, August 8, 2013 9:07:59 PM UTC+2, Nightjar wrote:
On 08/08/2013 13:50, wrote:

On Thursday, August 8, 2013 10:56:43 AM UTC+2, Nightjar wrote:

On 06/08/2013 13:56, wrote:



...



After about 2 hours struggling, I finally managed to get enough clearance under the motor box lid to swap the config over from star to delta. So am now looking at the Big Switch On sometime this afternoon and hoping for zero explosions or flashes/bangs as I don't think my nerves can stand it.











The lack of follow-up postings to tell us all went well is slightly



worrying.



Oh, sorry. Well, I did perform the big SWITCH-ON and took cover, but nothing happened. Nothing at all. Completely dead.



At least you are still with us :-)



Having done a bit of research on the net, it seems one has to connect the output of the converter direct to the motor. I'd actually connected it to the lathe's existing 3 phase cable which goes off into a complex switchbox expecting 415 Volts. The converter's output is 3 phase alright, but at only 230V. Obvious in retrospect, but an easy error to make at the time.

Unfortunately there's a so-called 'suds' motor which powers the coolant pump and it requires 400V. If that turns out to be dual voltage too, then I could connect it up delta and power it from the converter, but then the coolant rate will vary in tune with the main motor speed control provided by the converter!

It might be simpler to swap the suds motor for a 230v one.



They are cheap enough, assuming you don't have one like I had in a tool

and cutter grinding machine. The motor casing was part of the machine

casting and, when the motor failed, the only option (the manufacturer

being long gone) was to send the entire machine away to have the motor

re-wound.


I have a bit of luck in this regard. I removed an old jacussi bath a few months ago (don't think it had ever been used) which came with a 230v motor and a pump, which for some reason I thankfully held on to. They're in a single unit and should be ideal for use squirting coolant at hot spinning metal..