Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

cheers,
cd.

"Cursitor Doom" wrote in message
...
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

cheers,
cd.

Google:- "three phase motor reversing switch."

On Mon, 28 Apr 2014 19:55:36 +0100, "harryagain"
wrote:


"Cursitor Doom" wrote in message
.. .
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

cheers,
cd.

Google:- "three phase motor reversing switch."

Thanks. I was just hoping there might be something off-the-shelf I
could get from my local electricians' supply company. Would a more
conventional switch not work??

On 28/04/2014 22:01, Cursitor Doom wrote:
On Mon, 28 Apr 2014 19:55:36 +0100, "harryagain"
wrote:


"Cursitor Doom" wrote in message
...
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

cheers,
cd.

Google:- "three phase motor reversing switch."

Thanks. I was just hoping there might be something off-the-shelf I
could get from my local electricians' supply company.

I would be surprised if they couldn't supply one, either off the shelf
or next day.

Would a more
conventional switch not work??

You need a three-pole 2-way centre off switch, with two of the poles'
outputs cross-wired.

Colin Bignell

On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1 (i.e.
reversed) and connect the common to the load.

--
Cheers,

John.

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

In article ,
John Rumm writes:
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

Or even an intermediate light switch (not at 30A though).

feed L1 and L2 into one side, connect the other side to L2 and L1 (i.e.
reversed) and connect the common to the load.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Monday, April 28, 2014 7:41:01 PM UTC+1, Cursitor Doom wrote:

Hi, leccies,
I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?
cheers,
cd.

2 pole 2 way, aka DPDT, or a crossover switch would also do it


NT

In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1 (i.e.
reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

My ancient Boxford had a simple rotary switch before I converted it to
single phase. I sometimes wondered about the likelihood of unthreading
the chuck:-)


--
Tim Lamb

On 29/04/2014 09:18, Tim Lamb wrote:
In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1
(i.e. reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

Possibly not, if you are using a DPDT switch only as a reverser as 'off'
would still leave one phase connected. IMO the right way to do it is a
three pole two way centre off switch.

My ancient Boxford had a simple rotary switch before I converted it to
single phase. I sometimes wondered about the likelihood of unthreading
the chuck:-)

IME, something that is not that easy to do even hitting the chuck key
with a large hammer.

Colin Bignell

On Tue, 29 Apr 2014 10:04:47 +0100, Nightjar
wrote:

On 29/04/2014 09:18, Tim Lamb wrote:
In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1
(i.e. reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

Possibly not, if you are using a DPDT switch only as a reverser as 'off'
would still leave one phase connected. IMO the right way to do it is a
three pole two way centre off switch.

My ancient Boxford had a simple rotary switch before I converted it to
single phase. I sometimes wondered about the likelihood of unthreading
the chuck:-)

IME, something that is not that easy to do even hitting the chuck key
with a large hammer.

Got a camlock system on mine so it's not a problem. :-
Cheers for the advice, gentlemen. Nice to know I'm not going to end up
installing something that would be dangerous or in violation of the
Regs.

On 29/04/2014 09:18, Tim Lamb wrote:
In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1
(i.e. reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

It kind of goes without saying, that flipping the switch with it running
would not be a "good thing" (tm)

Perhaps a better solution would be to use a DPDT contactor to do the
actual switching, and wire that such that its locked out when the lathe
is running.

My ancient Boxford had a simple rotary switch before I converted it to
single phase. I sometimes wondered about the likelihood of unthreading
the chuck:-)

Lots of lathes seem to use quite aggressive breaking on the chuck these
days - so its probably not that easy to do by accident.


--
Cheers,

John.

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

On Tuesday, April 29, 2014 12:43:52 PM UTC+1, John Rumm wrote:
On 29/04/2014 09:18, Tim Lamb wrote:
In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:

Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1
(i.e. reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

It kind of goes without saying, that flipping the switch with it running
would not be a "good thing" (tm)

Indeed. The motor would survive it though. To discourage it you could always size the fuse to pop if someone does that.

A 3 position switch isnt going to solve deliberate abuse. If you only switch 2 wires you should definitely not use a 3 position switch, it may result in a burnt out motor.


NT

On 29/04/2014 12:43, John Rumm wrote:
On 29/04/2014 09:18, Tim Lamb wrote:
In message , John
Rumm writes
On 28/04/2014 19:41, Cursitor Doom wrote:
Hi, leccies,


I've got this single to three phase converter running a lathe motor;
230v in, 230v out. I'd like the ability to swap phases over so I can
reverse the motor to run the lathe in the opposite direction should
the situation call for it. The motor's max current draw is just under
30A. What's the technical name for the kind of switchbox which could
be wired up in series with the converter's output to swap a couple of
phases over? Or better yet, a link to a suitable product on the web?

Any Double pole Double throw switch can be wired to do that...

feed L1 and L2 into one side, connect the other side to L2 and L1
(i.e. reversed) and connect the common to the load.

Umm.. might be nice to have *centre off* at least or some link to break
the converter output where the lathe is running at speed.

It kind of goes without saying, that flipping the switch with it running
would not be a "good thing" (tm)

Perhaps a better solution would be to use a DPDT contactor to do the
actual switching, and wire that such that its locked out when the lathe
is running.

That is starting to get more complex (and probably more expensive) than
simply using a three-phase reversing switch.

My ancient Boxford had a simple rotary switch before I converted it to
single phase. I sometimes wondered about the likelihood of unthreading
the chuck:-)

Lots of lathes seem to use quite aggressive breaking on the chuck these
days - so its probably not that easy to do by accident.

IME often quite difficult to do on purpose.

Colin Bignell

On Tue, 29 Apr 2014 14:53:24 +0100, Nightjar
wrote:

That is starting to get more complex (and probably more expensive) than
simply using a three-phase reversing switch.

Yes, and a pity on one seems to make such a beast. You'd have thought
it a common enough requirement, wouldn't you? I mean, a switch which
just swaps two wires over, but apparantly they don't exist! That's
what the two biggest electrical factors where I live have just told
me, anyway. I've never seen service counter staff look so completely
baffled. :-(

On 29/04/2014 15:21, Cursitor Doom wrote:
On Tue, 29 Apr 2014 14:53:24 +0100, Nightjar
wrote:

That is starting to get more complex (and probably more expensive) than
simply using a three-phase reversing switch.

Yes, and a pity on one seems to make such a beast. You'd have thought
it a common enough requirement, wouldn't you? I mean, a switch which
just swaps two wires over, but apparantly they don't exist! That's
what the two biggest electrical factors where I live have just told
me, anyway. I've never seen service counter staff look so completely
baffled. :-(

You probably need a machine tool or control gear supplier, although you
can always assemble your own:

http://uk.rs-online.com/web/p/rotary-switches/2225936/
http://uk.rs-online.com/web/p/rotary...sories/3500840

Colin Bignell

In article ,
Cursitor Doom wrote:
On Tue, 29 Apr 2014 14:53:24 +0100, Nightjar
wrote:

That is starting to get more complex (and probably more expensive) than
simply using a three-phase reversing switch.

Yes, and a pity on one seems to make such a beast. You'd have thought
it a common enough requirement, wouldn't you? I mean, a switch which
just swaps two wires over, but apparantly they don't exist! That's
what the two biggest electrical factors where I live have just told
me, anyway. I've never seen service counter staff look so completely
baffled. :-(

We had a lathe at school - many years ago - that had a rotary switch to
reverse it. Three position - centre off. It was such a chunky device
likely no contactors involved. But H&S would have a fit today.

I'd say you'd have more chance looking for something like that at a
machine tool place - rather than a general electrical wholesaler.

RS components do a number of rotary switches designed for the job. One
such is the 20 amp 350-5615 which is about 15 quid bare - but you'll need
a handle and enclosure.

--
*Support bacteria - they're the only culture some people have *

Dave Plowman London SW
To e-mail, change noise into sound.

On 29/04/2014 16:31, Dave Plowman (News) wrote:
....
We had a lathe at school - many years ago - that had a rotary switch to
reverse it. Three position - centre off. It was such a chunky device
likely no contactors involved. But H&S would have a fit today...

The Dewhurst drum switch? The only thing between you and 415v being a
bent piece metal held on with a single screw and two metal lugs. The
cover is back to front on the top image he

http://www.instructables.com/id/Wiri...t-drum-switch/

Colin Bignell

On Tue, 29 Apr 2014 17:23:41 +0100, Nightjar
wrote:

On 29/04/2014 16:31, Dave Plowman (News) wrote:
...
We had a lathe at school - many years ago - that had a rotary switch to
reverse it. Three position - centre off. It was such a chunky device
likely no contactors involved. But H&S would have a fit today...

The Dewhurst drum switch? The only thing between you and 415v being a
bent piece metal held on with a single screw and two metal lugs. The
cover is back to front on the top image he

http://www.instructables.com/id/Wiri...t-drum-switch/

Colin Bignell

Yeah, but times move on. Remember the early electric kettles with the
two bare terminals at the back? The thing was in those days, electrics
were so dangerous that you didn't misuse them - or you died. It
sharpens the mind wonderfully, don't you think? That's the problem
with all this health n safety these days; it's making people very
careless.

Anyway, panic over. I have discovered that buried within the menu
system of the phase converter that drives this motor is an option to
reverse the drive. I thought there HAD to be one in there somewhere,
given the astonishing number of other less vital options the damn
thing boasts. Other models have the switch prominently on the front
panel, but not this one for some strange reason. :-/

In article , Cursitor Doom
scribeth thus
On Tue, 29 Apr 2014 14:53:24 +0100, Nightjar
wrote:

That is starting to get more complex (and probably more expensive) than
simply using a three-phase reversing switch.

Yes, and a pity on one seems to make such a beast. You'd have thought
it a common enough requirement, wouldn't you? I mean, a switch which
just swaps two wires over, but apparantly they don't exist! That's
what the two biggest electrical factors where I live have just told
me, anyway. I've never seen service counter staff look so completely
baffled. :-(

A mains/generator changeover switch would be the thing for this, it's a
double pole changeover switch with Break before Make being the important
part!...


You surely don't expect the man behind the counter in an electrical
wholesalers to know that much about actual circuitry do you;?..
--
Tony Sayer