I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
fan motor in it is single phase. (110V). I verified that the welder
powers up on 3 phase 240V. (after I rewired it).

My question is, is it safe to run it on single phase 240V (provided
that I select the right wires to power signal transformer and fan). If
so, what would be a safe reduced output amperage for welding. For 3
phase, it is rated 200 A continuous, I believe.

It would be great if that was possible, at least for small projects.
I could use some 8/3 cable that I have, not worry about the phase
converter etc.

i

Forgot to say, its transformer diagram seems to be triangular,
IIRC. It is a "three transformers and a rectifier" kind of welder. I
will double check this, I have all schematics.

i

On Thu, 22 Sep 2005 16:57:48 GMT, Ignoramus26924 wrote:
I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
fan motor in it is single phase. (110V). I verified that the welder
powers up on 3 phase 240V. (after I rewired it).

My question is, is it safe to run it on single phase 240V (provided
that I select the right wires to power signal transformer and fan). If
so, what would be a safe reduced output amperage for welding. For 3
phase, it is rated 200 A continuous, I believe.

It would be great if that was possible, at least for small projects.
I could use some 8/3 cable that I have, not worry about the phase
converter etc.

i



--

get a surplus 3 phase motor. You can
run these off single phase AC, and get 3 phase
off the other terminals. You can find these
motors for cheap or free

"Ignoramus26924" wrote in message
...
| I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
| fan motor in it is single phase. (110V). I verified that the welder
| powers up on 3 phase 240V. (after I rewired it).
|
| My question is, is it safe to run it on single phase 240V (provided
| that I select the right wires to power signal transformer and fan). If
| so, what would be a safe reduced output amperage for welding. For 3
| phase, it is rated 200 A continuous, I believe.

Since you have the schematics, does it explain how to hook it up to 240
two phase? I think that if you don't hit the full current capacity of the
welder, you ought to be okay. Make sure you have the wall current required
to drive it on two phase, though. The manual ought to discuss the derating.
If it doesn't show that its possible (I think unlikely) then your RPC
ought to drive it with the derating considered.

carl mciver wrote:
Since you have the schematics, does it explain how to hook it up to 240
two phase?

I think that is covered in the on/off section.

On Thu, 22 Sep 2005 19:19:32 GMT, Ignoramus26924
wrote:

On Thu, 22 Sep 2005 19:10:06 GMT, carl mciver wrote:
"Ignoramus26924" wrote in message
...
| I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
| fan motor in it is single phase. (110V). I verified that the welder
| powers up on 3 phase 240V. (after I rewired it).
|
| My question is, is it safe to run it on single phase 240V (provided
| that I select the right wires to power signal transformer and fan). If
| so, what would be a safe reduced output amperage for welding. For 3
| phase, it is rated 200 A continuous, I believe.

Since you have the schematics, does it explain how to hook it up to 240
two phase?

You mean single phase, right?

I will check if it says anything to that effect.

I do recall the delta shaped schematic of the transformer/rectifier
setup. A delta shaped triangular transformer and rectifiers.

That's the schematic. You need to look closer inside. I'm betting
that delta schematic is all in one transformer. If you go to hooking
all of them up to the same single phase I'm afraid they might fight
each other in the transformer.

I am kind of hoping that I could, possibly, rewire just the power
terminal board in such a way that all three sides of that triangle
rectify the same single phase.

I have my doubts. If it could be done we'd of heard about it by now.
There's been more than one electrical brain work with these machines.

That way, I would end up having a single phase welder. The only
downside that I could see is that the shape of the resulting waveform
could, possibly, be less flat due to lack of smoothing from rectifying
3 phase AC.

That and burning out the transformer.


I think that if you don't hit the full current capacity of the
welder, you ought to be okay. Make sure you have the wall current required
to drive it on two phase, though. The manual ought to discuss the derating.

I will check the manual. In fact, I want to read most of it.

Unless the input tag on the back of the machine lists single phase
as a possible input then it won't be in the manual.

If it doesn't show that its possible (I think unlikely) then your RPC
ought to drive it with the derating considered.

My RPC does drive it, at least to the point of simply powering it up
with no load. I am not sure why the welder would need derating,
provided that the RPC is up to needed capacity.

Correct. This is a smaller welder so you should have no problems
with the two phase converters you've got running it.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

On Thu, 22 Sep 2005 17:04:48 GMT, Ignoramus26924
wrote:

Forgot to say, its transformer diagram seems to be triangular,
IIRC. It is a "three transformers and a rectifier" kind of welder. I
will double check this, I have all schematics.


Actually there's more to it than that. I bet if you open it you'll
find that the three transformers are all in one core. Then there's the
reactor which is used to control current. The reactor itself is
controlled with SCR's. After all of that then there's the diodes.

Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

Carl,

Where have you been all the years and through all the posts on RCM
disclaiming 240V 2-PHASE current? There is no such thing available in the
ordinary US residence. 240v SINGLE PHASE current is what just about all
residences have in the US. It comes in on 3 wires, one of them being the
center tap of the transformer. It is center tapped to provide 240 volts
across the entire winding and 2 sides of 120V each.

Try not to confuse Iggy by giving him erronious information - he has enough
trouble with the real facts.

Bob Swinney


"carl mciver" wrote in message
ink.net...
"Ignoramus26924" wrote in message
...
| I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
| fan motor in it is single phase. (110V). I verified that the welder
| powers up on 3 phase 240V. (after I rewired it).
|
| My question is, is it safe to run it on single phase 240V (provided
| that I select the right wires to power signal transformer and fan). If
| so, what would be a safe reduced output amperage for welding. For 3
| phase, it is rated 200 A continuous, I believe.

Since you have the schematics, does it explain how to hook it up to 240
two phase? I think that if you don't hit the full current capacity of the
welder, you ought to be okay. Make sure you have the wall current
required
to drive it on two phase, though. The manual ought to discuss the
derating.
If it doesn't show that its possible (I think unlikely) then your RPC
ought to drive it with the derating considered.

Sounds like it might be wired in a Delta.
Likely - as a missing phase won't knock you out - you have a 2/3 power ability.

Now - think of your 3 phase gen - you put in 220 - a phase at zero (0) another phase at 180 .
You generate the missing phase at 90. So 0,90,180 are the 'zero' marks for the positive alternations.

If you put all three phases to the transformer - 3 phase. If you knock out the wild one - 90 -
the ends are there - if you really have a delta wired transformer(s) then an Open V , inverted D
(several tag names ) condition occurs. 2/3 power is the max.

Security places from Police to ... all of them use Delta x Delta transformers. If an input line/winding
is 'lost' then the system survives. What they do is beef up the VA rating so
in this lost mode they run 100% other modes they have more than planned for.

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Ignoramus26924 wrote:
Forgot to say, its transformer diagram seems to be triangular,
IIRC. It is a "three transformers and a rectifier" kind of welder. I
will double check this, I have all schematics.

i

On Thu, 22 Sep 2005 16:57:48 GMT, Ignoramus26924 wrote:

I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
fan motor in it is single phase. (110V). I verified that the welder
powers up on 3 phase 240V. (after I rewired it).

My question is, is it safe to run it on single phase 240V (provided
that I select the right wires to power signal transformer and fan). If
so, what would be a safe reduced output amperage for welding. For 3
phase, it is rated 200 A continuous, I believe.

It would be great if that was possible, at least for small projects.
I could use some 8/3 cable that I have, not worry about the phase
converter etc.

i





----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

According to Ignoramus26924 :
On Thu, 22 Sep 2005 20:04:47 -0500, Wayne Cook wrote:
On Thu, 22 Sep 2005 17:04:48 GMT, Ignoramus26924
wrote:

Forgot to say, its transformer diagram seems to be triangular,
IIRC. It is a "three transformers and a rectifier" kind of welder. I
will double check this, I have all schematics.


Actually there's more to it than that. I bet if you open it you'll
find that the three transformers are all in one core. Then there's the
reactor which is used to control current. The reactor itself is
controlled with SCR's. After all of that then there's the diodes.

I doubt that they have the same core, otherwise they would be
basically all on one phase, transforming one another.

You haven't seen many three-phase transformers, then. Picture
the usual 'E' laminations, except a bit more widely spaced. One winding
goes around the normal center pole, and the other two go around the top
and bottom bars of the 'E'. The phasing is such that the fields merge
cleanly.

Take a look at what is physically inside your machine, and then
come back and say that it can't be done. :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Yeah, yeah, I know. My bad. I boo-booed. Will you whip me, spank me,
and make me write bad checks? Threaten me with a good time? Pretty please?

I still have this thing in my head after all these years of seeing the
two legs 180 out of phase, with the neutral in the middle, so it still comes
out as two phases in my head, even though I know better.

Better to call me on it than for me to confuse anyone even more,
although I give Iggy credit, he asks a lot of questions before he blows
something up, rather than afterwards. He's obviously well spoken and
intelligent; obviously not a product of American public schools, and for
that I enjoy his posts. He rarely asks a question or gives a response that
he hasn't given some thought to, unlike me!

"Robert Swinney" wrote in message
...
| Carl,
|
| Where have you been all the years and through all the posts on RCM
| disclaiming 240V 2-PHASE current? There is no such thing available in the
| ordinary US residence. 240v SINGLE PHASE current is what just about all
| residences have in the US. It comes in on 3 wires, one of them being the
| center tap of the transformer. It is center tapped to provide 240 volts
| across the entire winding and 2 sides of 120V each.
|
| Try not to confuse Iggy by giving him erronious information - he has
enough
| trouble with the real facts.
|
| Bob Swinney

On Thu, 22 Sep 2005 17:16:41 GMT, Ignoramus26924
wrote:

On 22 Sep 2005 10:15:13 -0700, wrote:
get a surplus 3 phase motor. You can
run these off single phase AC, and get 3 phase
off the other terminals. You can find these
motors for cheap or free

Thanks. I already have a phase converter with a surplus motor, it runs
fine etc. Still, it would be nice to run the cybertig without a phase
converter.

i

No can do with this welder, Ive been told by a welding machine repair
tech.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

On Fri, 23 Sep 2005 10:16:50 GMT, Ignoramus19652
wrote:

On Fri, 23 Sep 2005 07:54:45 GMT, Gunner wrote:
On Thu, 22 Sep 2005 17:16:41 GMT, Ignoramus26924
wrote:

On 22 Sep 2005 10:15:13 -0700, wrote:
get a surplus 3 phase motor. You can
run these off single phase AC, and get 3 phase
off the other terminals. You can find these
motors for cheap or free

Thanks. I already have a phase converter with a surplus motor, it runs
fine etc. Still, it would be nice to run the cybertig without a phase
converter.

i

No can do with this welder, Ive been told by a welding machine repair
tech.

Thanks Gunner...

i

http://www.arcowelder.com/

Give Dennis a call. He is one of the sharpest welding machine guys Ive
ever met, and has docs for just about anything you will ever stumble
across.

Be sure to tell him Gunner refered you. That way he will know how much
to jack up the price G

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Ignoramus26924 wrote:
On Thu, 22 Sep 2005 21:10:13 -0500, Martin H. Eastburn wrote:

Sounds like it might be wired in a Delta.
Likely - as a missing phase won't knock you out - you have a 2/3 power ability.


That's where you confuse me. Is it 2/3 ability or 1/3 ability? If only
one side of the three sided "delta" is in operation, that should
logically put out only 1/3 of power.

Read again. You have a 2/3's power ability when one is not functional.


Now - think of your 3 phase gen - you put in 220 - a phase at zero
(0) another phase at 180 . You generate the missing phase at 90.
So 0,90,180 are the 'zero' marks for the positive alternations.


The angles are actually 0, 120, and 240. (or, for all zero crossings,
0 60 120 180 240 300 360=0)

I'm going to have to look at my books now - not my mind - If those are
the angles - looks like 30 HZ to me.
How do you shift one phase in by 60 or out by a bunch and then generate a third ?
Only the wild is generated the other two generate fields and run.

I looked it up and it is 120 degrees between phases. Nice power supply concepts
in section 12-3 - see version below on zig-zag.


If you put all three phases to the transformer - 3 phase. If you
knock out the wild one - 90 - the ends are there - if you really
have a delta wired transformer(s) then an Open V , inverted D
(several tag names ) condition occurs. 2/3 power is the max.


Maybe... What I am thinking about is this. This is a delta wound
transformer. Think about a triangle with points A, B, C.


C
/ \
A---B

Let's say that A and B represent utility power legs, and C is the wild
leg. There is nominal 240V between A-B, A-C, and B-C. Each line in
this diagram represents one transformer core, one 240V primary and one
low voltage secondary. Volts from secondaries are rectified and
"united" together, care being taken with diodes to avoid shorts.
This might only work in a single core since the two generate the third.


What I would like, if possible, is to change this to:


B B
/ \
A A

A------B

that is, there will not be any longer contact between sides of cores,
instead each core/transformer would step down the same phase. Then,
the same rectifiers will convert it to DC.
If there was 3 phase already (like the power company) then stepping down
a voltage and keeping the same phase is ok.
But this (the ABC windings) have to be in one core and connected. You have them
that way but the connection is in the panel or somewhere else. B = B somewhere.

The power that is output by this setup should logically be not too far
from the power from 3 phase .
Like I have said before - if you already have 3 phase it is a step down/step up.
Power company does it all of the time.
It is far easier to mount three transformers on a pole than one Honker up there.
Many sites - Dr. Offices as an example - don't have a pad to mount a transformer
the size of a desk.

It is better to do WYE for rectifiers for AC anyway.

An example Zig-zag from another discussion is in paragraph 82 section 13-83
Standard handbook for Electrical Engineers - Tenth Edition.


What may suffer is the quality of the DC waveform. Instead of being
like this:

_______~~~~~~~___________

(underscores represent the zero level)

You should use 6 phase if you want smooth ripple.


it will be more like this:

_____/\/\/\/\________

In both cases the graph of voltage is all above zero, but the top one
is more stable.

This waveworm issue may possibly interfere with arc stability.

Also, the control system may expect certain phase differences between
legs to run properly.

That's my ignorant take on this issue.


Security places from Police to ... all of them use Delta x Delta
transformers. If an input line/winding is 'lost' then the system
survives. What they do is beef up the VA rating so in this lost
mode they run 100% other modes they have more than planned for.


That's very interesting to know. Thank you for your comment Martin.

i


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Bob -
there is 180 degrees phase between the two lines.
It isn't DC And the phase can be -90 and +90. Depends on the reference .


Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Robert Swinney wrote:
Carl,

Where have you been all the years and through all the posts on RCM
disclaiming 240V 2-PHASE current? There is no such thing available in the
ordinary US residence. 240v SINGLE PHASE current is what just about all
residences have in the US. It comes in on 3 wires, one of them being the
center tap of the transformer. It is center tapped to provide 240 volts
across the entire winding and 2 sides of 120V each.

Try not to confuse Iggy by giving him erronious information - he has enough
trouble with the real facts.

Bob Swinney


"carl mciver" wrote in message
ink.net...

"Ignoramus26924" wrote in message
. ..
| I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
| fan motor in it is single phase. (110V). I verified that the welder
| powers up on 3 phase 240V. (after I rewired it).
|
| My question is, is it safe to run it on single phase 240V (provided
| that I select the right wires to power signal transformer and fan). If
| so, what would be a safe reduced output amperage for welding. For 3
| phase, it is rated 200 A continuous, I believe.

Since you have the schematics, does it explain how to hook it up to 240
two phase? I think that if you don't hit the full current capacity of the
welder, you ought to be okay. Make sure you have the wall current
required
to drive it on two phase, though. The manual ought to discuss the
derating.
If it doesn't show that its possible (I think unlikely) then your RPC
ought to drive it with the derating considered.





----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Don't start with me .....

Bob Swinney
"Martin H. Eastburn" wrote in message
...
Bob -
there is 180 degrees phase between the two lines.
It isn't DC And the phase can be -90 and +90. Depends on the reference .


Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Robert Swinney wrote:
Carl,

Where have you been all the years and through all the posts on RCM
disclaiming 240V 2-PHASE current? There is no such thing available in
the ordinary US residence. 240v SINGLE PHASE current is what just about
all residences have in the US. It comes in on 3 wires, one of them being
the center tap of the transformer. It is center tapped to provide 240
volts across the entire winding and 2 sides of 120V each.

Try not to confuse Iggy by giving him erronious information - he has
enough trouble with the real facts.

Bob Swinney


"carl mciver" wrote in message
ink.net...

"Ignoramus26924" wrote in message
...
| I have a Hobart CyberTig 200 DC-S welder. It is 3 phase, however, the
| fan motor in it is single phase. (110V). I verified that the welder
| powers up on 3 phase 240V. (after I rewired it).
|
| My question is, is it safe to run it on single phase 240V (provided
| that I select the right wires to power signal transformer and fan). If
| so, what would be a safe reduced output amperage for welding. For 3
| phase, it is rated 200 A continuous, I believe.

Since you have the schematics, does it explain how to hook it up to
240
two phase? I think that if you don't hit the full current capacity of
the
welder, you ought to be okay. Make sure you have the wall current
required
to drive it on two phase, though. The manual ought to discuss the
derating.
If it doesn't show that its possible (I think unlikely) then your RPC
ought to drive it with the derating considered.





----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----