Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).
I had planned to use manual switchgear or perhaps relays, but it seems
nowadays these things called 'contactors' are all the rage. Being a
bit er, "mature" in years I'm completely unfamiliar with these
new-fangled devices.
I will need to switch the current from the converter between the two
different motors depending on whether I'm using the lathe or the mill.
Let's say the peak current for both will not exceed 25A and as I've
already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

cheers,

cd.

On 12/07/2014 18:37, Cursitor Doom wrote:
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).
I had planned to use manual switchgear or perhaps relays, but it seems
nowadays these things called 'contactors' are all the rage. Being a
bit er, "mature" in years I'm completely unfamiliar with these
new-fangled devices.
I will need to switch the current from the converter between the two
different motors depending on whether I'm using the lathe or the mill.
Let's say the peak current for both will not exceed 25A and as I've
already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

cheers,

cd.

"Contactor" is the currently fashionable name for a heavy current relay
or switch.

The cheap and easy way to do it is to use a three pole, two way, centre
off unit like the one I use to switch between shore supply and inverter
supply on the boat. I paid just under £40 plus the cost of the box.

--
Tciao for Now!

John.

On Sat, 12 Jul 2014 19:37:20 +0200, Cursitor Doom wrote:

Now, precisely what type of 'contactor' will I need to switch between
the two machines?

AIUI a "contactor" is just a fancy word for BFO mains relay.

Why not KISS and fit a 3ph Ceeform socket to the output of the
convertor and matching plugs on the input cables to the lathe and
mill.

--
Cheers
Dave.

On 12/07/14 19:22, John Williamson wrote:

"Contactor" is the currently fashionable name for a heavy current relay
or switch.

I think it's been fashionable since 1950

On Saturday, July 12, 2014 10:09:05 PM UTC+1, Tim Watts wrote:
On 12/07/14 19:22, John Williamson wrote:



"Contactor" is the currently fashionable name for a heavy current relay

or switch.



I think it's been fashionable since 1950

I think it has always been 'contactor' for ac drive and 'relay' for dc drive.

I will take the line oft repeated here that if the OP's electrical power knowledge is that lacking, should he actually be tackling such a task ?

One thought that does come to mind is that an inverter should be fed from a 'No Volts' contactor which is linked into the emergency off circuits; this is so that the inverter is isolated from the mains if there is a trip, and doesn't restart if the trip only is reset - I've been there and nearly suffered when working on someone else's machinery.

If the OP is not aware of what a 'contactor' is, it makes me worry that his whole system is not covered by emergency trips and, having initially thought the 3ph socket solution was favourable, I now realise that it is in fact extremely hazardous unless suitable wiring from the emergency buttons is incorporated.

On Saturday, July 12, 2014 6:37:20 PM UTC+1, Cursitor Doom wrote:
Hi there, sparkses,

already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

3 pole 2 way


NT

On Sat, 12 Jul 2014 15:07:02 -0700 (PDT), robgraham
wrote:

I now realise that it is in fact extremely hazardous unless suitable wiring from the emergency buttons is incorporated.

Too much aggro. I like simple safety precautions, like a thick rubber
mat under the working area immediately in front of the machine.
In an ideal world it would be nice to have safety this and safety
that, but at the end of the day, you'd get no work done, so what can
you do?

On 12/07/2014 23:07, robgraham wrote:
On Saturday, July 12, 2014 10:09:05 PM UTC+1, Tim Watts wrote:
On 12/07/14 19:22, John Williamson wrote:



"Contactor" is the currently fashionable name for a heavy current
relay

or switch.



I think it's been fashionable since 1950

I think it has always been 'contactor' for ac drive and 'relay' for
dc drive.

I will take the line oft repeated here that if the OP's electrical
power knowledge is that lacking, should he actually be tackling such
a task ?

One thought that does come to mind is that an inverter should be fed
from a 'No Volts' contactor which is linked into the emergency off
circuits; this is so that the inverter is isolated from the mains if
there is a trip, and doesn't restart if the trip only is reset - I've
been there and nearly suffered when working on someone else's
machinery.

Many machines have their own built in No Volts contactor.

If the OP is not aware of what a 'contactor' is, it makes me worry
that his whole system is not covered by emergency trips and, having
initially thought the 3ph socket solution was favourable, I now
realise that it is in fact extremely hazardous unless suitable wiring
from the emergency buttons is incorporated.

This is something I need to look into myself. What are the requirement
for emergency stop switches?

"Cursitor Doom" wrote in message
...
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).
I had planned to use manual switchgear or perhaps relays, but it seems
nowadays these things called 'contactors' are all the rage. Being a
bit er, "mature" in years I'm completely unfamiliar with these
new-fangled devices.
I will need to switch the current from the converter between the two
different motors depending on whether I'm using the lathe or the mill.
Let's say the peak current for both will not exceed 25A and as I've
already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

cheers,

cd.

As someone has said, the easy way is to put a socket on the output from your
inverter and have plugs on your machines.
You could use two contactors and a two way light switch to control the coils
on them.
However there are quite a few possible pitfalls. If you have to ask these
questions, maybe you should GSI (Get Someone In)

"Cursitor Doom" wrote in message
...
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).

I had planned to use manual switchgear

There is your answer. It's the stop start switch on the machine or am I
missing something - such as you have to program the invertor diferrently for
each machine and want it to automatically power the correct machine
depending on which program you have chosen?

--
Adam

"robgraham" wrote in message
...
On Saturday, July 12, 2014 10:09:05 PM UTC+1, Tim Watts wrote:
On 12/07/14 19:22, John Williamson wrote:



"Contactor" is the currently fashionable name for a heavy current relay

or switch.



I think it's been fashionable since 1950

I think it has always been 'contactor' for ac drive and 'relay' for dc
drive.


No - it's a power thing.

--
Adam

Yes, contactor is just a generic name. It could be anything inside, but as
long as the outcome is a switch over where both cannot be connected at the
same time, you are fine. The things that get me befuzzled are starters,
which seem to be able to keep from running big motors flat out at the
start, gradually spinning them up, this is very handy if there is a big mass
on the motor and you do not want to strip gears or burn it out!
Brian

--
From the Sofa of Brian Gaff Reply address is active
"John Williamson" wrote in message
...
On 12/07/2014 18:37, Cursitor Doom wrote:
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).
I had planned to use manual switchgear or perhaps relays, but it seems
nowadays these things called 'contactors' are all the rage. Being a
bit er, "mature" in years I'm completely unfamiliar with these
new-fangled devices.
I will need to switch the current from the converter between the two
different motors depending on whether I'm using the lathe or the mill.
Let's say the peak current for both will not exceed 25A and as I've
already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

cheers,

cd.

"Contactor" is the currently fashionable name for a heavy current relay or
switch.

The cheap and easy way to do it is to use a three pole, two way, centre
off unit like the one I use to switch between shore supply and inverter
supply on the boat. I paid just under £40 plus the cost of the box.

--
Tciao for Now!

John.

In article ,
John Williamson writes:
On 12/07/2014 18:37, Cursitor Doom wrote:
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).
I had planned to use manual switchgear or perhaps relays, but it seems
nowadays these things called 'contactors' are all the rage. Being a
bit er, "mature" in years I'm completely unfamiliar with these
new-fangled devices.
I will need to switch the current from the converter between the two
different motors depending on whether I'm using the lathe or the mill.
Let's say the peak current for both will not exceed 25A and as I've
already stated, this will be 230VAC 3 phase.
Now, precisely what type of 'contactor' will I need to switch between
the two machines?

cheers,

cd.

"Contactor" is the currently fashionable name for a heavy current relay
or switch.

A contactor is not symetric. The construction gives very high contact
pressure on the N/O contacts, but not on the N/C contacts (indeed
most contactors don't even have N/C contacts). This means the high
current rating applies only to N/O contacts.

Therefore, to build changeover functionality with contactors will
normally require two of them. There's usually some extra circuitry
to ensure both can't be energised at the same time, such as auxilliary
contacts locking the other one out.

2.2kW @ 3P 400V is not a high current, particularly given this case
is likely to be all off-load switching. A good relay will handle it
for a reasonable time, providing its contacts are rated for 400VAC.
Using a socketed relay would enable easy changing if it does wear
out.

Depending on the start circuits of the two appliances, you might
even manage without any switchover, but simply have each one when
operating disable the other one's start circuit or supply completely.
This would mean modifying the two appliances, but would make for
easier use.

The cheap and easy way to do it is to use a three pole, two way, centre
off unit like the one I use to switch between shore supply and inverter
supply on the boat. I paid just under £40 plus the cost of the box.

That's usually called a transfer switch, although in this case being
used in reverse.

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

On 13/07/2014 08:19, ARW wrote:
"robgraham" wrote in message
...
On Saturday, July 12, 2014 10:09:05 PM UTC+1, Tim Watts wrote:
On 12/07/14 19:22, John Williamson wrote:



"Contactor" is the currently fashionable name for a heavy current relay

or switch.



I think it's been fashionable since 1950

I think it has always been 'contactor' for ac drive and 'relay' for dc
drive.


No - it's a power thing.

I associate contactors with 3-phase.

On Sun, 13 Jul 2014 08:15:03 +0100, "ARW"
wrote:

"Cursitor Doom" wrote in message
.. .
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).

I had planned to use manual switchgear

There is your answer. It's the stop start switch on the machine or am I
missing something - such as you have to program the invertor diferrently for
each machine and want it to automatically power the correct machine
depending on which program you have chosen?

If you want to run 3 phase machinery but you don't have a 3 phase
supply, then one of your very few options is to use a phase converter
and change the motor box's delta/star configuration over. So far so
good.
However, the problem with phase converters is that you can't just
connect them up to the machine's 'distribution board' in the same way
you would with a standard 3 phase installation and enjoy full use of
everything. They have to be wired direct to the motor(s) concerned,
and this bypasses a lot of the safety features built in to the
machine. For example, by using a converter, you lose the functionality
of the 'big red stop button' plus any guards around rotating parts
won't cut the machine out when raised, and the foot-bar emergency stop
no longer works. This is not an exhaustive list!

"Cursitor Doom" wrote in message
...
On Sun, 13 Jul 2014 08:15:03 +0100, "ARW"
wrote:

"Cursitor Doom" wrote in message
. ..
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).

I had planned to use manual switchgear

There is your answer. It's the stop start switch on the machine or am I
missing something - such as you have to program the invertor diferrently
for
each machine and want it to automatically power the correct machine
depending on which program you have chosen?

If you want to run 3 phase machinery but you don't have a 3 phase
supply, then one of your very few options is to use a phase converter
and change the motor box's delta/star configuration over. So far so
good.

Yes you change from star to delta.

However, the problem with phase converters is that you can't just
connect them up to the machine's 'distribution board' in the same way
you would with a standard 3 phase installation and enjoy full use of
everything. They have to be wired direct to the motor(s) concerned,
and this bypasses a lot of the safety features built in to the
machine. For example, by using a converter, you lose the functionality
of the 'big red stop button' plus any guards around rotating parts
won't cut the machine out when raised, and the foot-bar emergency stop
no longer works. This is not an exhaustive list!

So you are bypassing the machines built in contactor.

--
Adam

On Sun, 13 Jul 2014 16:09:08 +0100, "ARW"
wrote:

So you are bypassing the machines built in contactor.

Neither of them have one so far as I know; unless they're called
something else in my universe.

"Cursitor Doom" wrote in message
news
On Sun, 13 Jul 2014 16:09:08 +0100, "ARW"
wrote:

So you are bypassing the machines built in contactor.

Neither of them have one so far as I know; unless they're called
something else in my universe.



Give a make and model number of your machines and I can probably help you
more with the wiring

--
Adam

On Sun, 13 Jul 2014 17:14:44 +0100, "ARW"
wrote:

"Cursitor Doom" wrote in message
news
On Sun, 13 Jul 2014 16:09:08 +0100, "ARW"
wrote:

So you are bypassing the machines built in contactor.

Neither of them have one so far as I know; unless they're called
something else in my universe.



Give a make and model number of your machines and I can probably help you
more with the wiring

Thanks but nothinssthaksbit ****ed

On Sun, 13 Jul 2014 12:15:48 +0200, Cursitor Doom wrote:

On Sun, 13 Jul 2014 08:15:03 +0100, "ARW"
wrote:

"Cursitor Doom" wrote in message
. ..
Hi there, sparkses,

I have a 2.2kw phase converter which outputs 230v AC 3 phase from a
standard single phase mains supply. This converter is currently
powering my 3HP lathe. But I've just bought a milling machine which
requires slightly less current so I wish to power them both from the
same converter (not at the same time, though, obviously!).

I had planned to use manual switchgear

There is your answer. It's the stop start switch on the machine or am I
missing something - such as you have to program the invertor diferrently for
each machine and want it to automatically power the correct machine
depending on which program you have chosen?

If you want to run 3 phase machinery but you don't have a 3 phase
supply, then one of your very few options is to use a phase converter
and change the motor box's delta/star configuration over. So far so
good.
However, the problem with phase converters is that you can't just
connect them up to the machine's 'distribution board' in the same way
you would with a standard 3 phase installation and enjoy full use of
everything. They have to be wired direct to the motor(s) concerned,
and this bypasses a lot of the safety features built in to the
machine. For example, by using a converter, you lose the functionality
of the 'big red stop button' plus any guards around rotating parts
won't cut the machine out when raised, and the foot-bar emergency stop
no longer works. This is not an exhaustive list!

Yes, but with an inverter there is nothing to stop you wiring it up so that all
the interlocks and stop buttons function as well as or maybe even better than
the factory original - It's relatively easy to use dc injection braking for the
motor for instance which has the potential to stop a motor very quickly.

There are also a few occasions when you might even want to bypass safety
features. An interlock switch on a chuck guard on a lathe can be a real pain in
the arse. Common sense informs you when you need to use it - almost but not
quite 100% of the time. Multiple emergency stop switches just below the drip
tray and within easy reach are IMHO better than any foot bar.

--

On Mon, 14 Jul 2014 17:35:29 +0100, The Other Mike
wrote:

Yes, but with an inverter there is nothing to stop you wiring it up so that all
the interlocks and stop buttons function as well as or maybe even better than
the factory original - It's relatively easy to use dc injection braking for the
motor for instance which has the potential to stop a motor very quickly.

DC injection braking? Can't say I've heard of that. Remember this is a
phase converter not an inverter. It takes 230VAC single phase and
outputs 230VAC 3 phase.

On Tuesday, July 15, 2014 8:58:19 PM UTC+1, Cursitor Doom wrote:
On Mon, 14 Jul 2014 17:35:29 +0100, The Other Mike

wrote:



Yes, but with an inverter there is nothing to stop you wiring it up so that all

the interlocks and stop buttons function as well as or maybe even better than

the factory original - It's relatively easy to use dc injection braking for the

motor for instance which has the potential to stop a motor very quickly.



DC injection braking? Can't say I've heard of that. Remember this is a

phase converter not an inverter. It takes 230VAC single phase and

outputs 230VAC 3 phase.

"a phase converter not an inverter" ??? would you like to clarify with respect to this :-
http://en.wikipedia.org/wiki/Phase_converter

as much of the discussion is, I suspect, considering exactly the input/output you have called up.

Strictly there is a difference between and 'inverter' and a 'converter', but that difference has become very much blurred as the Wikipedia article indicates.

Fredxxx wrote:
On 13/07/2014 08:19, ARW wrote:
"robgraham" wrote in message
...
On Saturday, July 12, 2014 10:09:05 PM UTC+1, Tim Watts wrote:
On 12/07/14 19:22, John Williamson wrote:



"Contactor" is the currently fashionable name for a heavy current
relay

or switch.



I think it's been fashionable since 1950

I think it has always been 'contactor' for ac drive and 'relay' for dc
drive.


No - it's a power thing.

I associate contactors with 3-phase.
I associate contactors with heavier switching devices with coils doing
the work

"robgraham" wrote in message
...
On Tuesday, July 15, 2014 8:58:19 PM UTC+1, Cursitor Doom wrote:
On Mon, 14 Jul 2014 17:35:29 +0100, The Other Mike

wrote:



Yes, but with an inverter there is nothing to stop you wiring it up so
that all

the interlocks and stop buttons function as well as or maybe even better
than

the factory original - It's relatively easy to use dc injection braking
for the

motor for instance which has the potential to stop a motor very quickly.



DC injection braking? Can't say I've heard of that. Remember this is a

phase converter not an inverter. It takes 230VAC single phase and

outputs 230VAC 3 phase.

"a phase converter not an inverter" ??? would you like to clarify with
respect to this :-
http://en.wikipedia.org/wiki/Phase_converter

as much of the discussion is, I suspect, considering exactly the
input/output you have called up.

Strictly there is a difference between and 'inverter' and a 'converter',
but that difference has become very much blurred as the Wikipedia article
indicates.


You can make your own convertors:-).

Probably one one best videos I have seen for a while as it is made by a mad
man

https://www.youtube.com/watch?v=6UcDM3hm0XM


--
Adam