Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > sci.electronics.design > #434222 > unrolled thread

Single or double pole mains switch in USA?

Started bySyd Rumpo <usenet@nononono.co.uk>
First post2016-11-08 09:41 +0000
Last post2016-11-12 07:05 +0000
Articles 20 on this page of 49 — 15 participants

Back to article view | Back to sci.electronics.design


Contents

  Single or double pole mains switch in USA? Syd Rumpo <usenet@nononono.co.uk> - 2016-11-08 09:41 +0000
    Re: Single or double pole mains switch in USA? jrwalliker@gmail.com - 2016-11-08 06:10 -0800
      Re: Single or double pole mains switch in USA? John Larkin <jjlarkin@highlandtechnology.com> - 2016-11-08 06:29 -0800
        Re: Single or double pole mains switch in USA? Martin Riddle <martin_ridd@verizon.net> - 2016-11-08 11:55 -0500
          Re: Single or double pole mains switch in USA? Martin Riddle <martin_ridd@verizon.net> - 2016-11-08 11:56 -0500
    Re: Single or double pole mains switch in USA? Martin Riddle <martin_ridd@verizon.net> - 2016-11-08 11:58 -0500
      Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-08 11:05 -0600
        Re: Single or double pole mains switch in USA? krw <krw@nowhere.com> - 2016-11-08 12:48 -0500
        Re: Single or double pole mains switch in USA? jurb6006@gmail.com - 2016-11-08 10:46 -0800
        Re: Single or double pole mains switch in USA? M Philbrook <jamie_ka1lpa@charter.net> - 2016-11-08 17:22 -0500
          Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-11 20:22 -0600
          Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-11 20:26 -0600
            Re: Single or double pole mains switch in USA? DJ Delorie <dj@delorie.com> - 2016-11-11 22:07 -0500
              Re: Single or double pole mains switch in USA? M Philbrook <jamie_ka1lpa@charter.net> - 2016-11-12 12:03 -0500
                Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-12 12:34 -0600
                  Re: Single or double pole mains switch in USA? M Philbrook <jamie_ka1lpa@charter.net> - 2016-11-12 16:20 -0500
                    Re: Single or double pole mains switch in USA? pedro <me@privacy.net> - 2016-11-13 09:32 +0800
                      Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-12 19:52 -0600
                        Re: Single or double pole mains switch in USA? Jasen Betts <jasen@xnet.co.nz> - 2016-11-13 05:11 +0000
                          Re: Single or double pole mains switch in USA? M Philbrook <jamie_ka1lpa@charter.net> - 2016-11-13 13:07 -0500
                            Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-13 16:44 -0600
                        Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-13 18:13 -0500
                    Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-12 19:48 -0600
                      Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-12 20:56 -0500
                        Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-12 20:10 -0600
                          Re: Single or double pole mains switch in USA? Jasen Betts <jasen@xnet.co.nz> - 2016-11-13 04:57 +0000
                            Re: Single or double pole mains switch in USA? upsidedown@downunder.com - 2016-11-13 11:07 +0200
                            Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-13 09:57 -0600
                          Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-13 18:14 -0500
                            Re: Single or double pole mains switch in USA? upsidedown@downunder.com - 2016-11-14 21:19 +0200
                              Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-14 19:54 -0500
                                Re: Single or double pole mains switch in USA? upsidedown@downunder.com - 2016-11-15 09:55 +0200
                                  Re: Single or double pole mains switch in USA? Glen Walpert <nospam@null.void> - 2016-11-15 17:55 +0000
                            Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-14 17:39 -0600
                              Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-14 19:55 -0500
                            Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-14 17:46 -0600
                              Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-14 19:56 -0500
                                Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-15 17:00 -0600
                                  Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-15 19:20 -0500
                Re: Single or double pole mains switch in USA? upsidedown@downunder.com - 2016-11-12 20:53 +0200
                Re: Single or double pole mains switch in USA? jurb6006@gmail.com - 2016-11-13 10:50 -0800
                  Re: Single or double pole mains switch in USA? jurb6006@gmail.com - 2016-11-13 10:58 -0800
              Re: Single or double pole mains switch in USA? John S <Sophi.2@invalid.org> - 2016-11-12 12:31 -0600
    Re: Single or double pole mains switch in USA? krw <krw@nowhere.com> - 2016-11-08 12:46 -0500
      Re: Single or double pole mains switch in USA? jurb6006@gmail.com - 2016-11-08 10:40 -0800
        Re: Single or double pole mains switch in USA? krw <krw@somewhere.com> - 2016-11-08 19:13 -0500
    Re: Single or double pole mains switch in USA? whit3rd <whit3rd@gmail.com> - 2016-11-08 10:50 -0800
    Re: Single or double pole mains switch in USA? Syd Rumpo <usenet@nononono.co.uk> - 2016-11-09 14:06 +0000
    Re: Single or double pole mains switch in USA? Jasen Betts <jasen@xnet.co.nz> - 2016-11-12 07:05 +0000

Page 2 of 3 — ← Prev page 1 [2] 3  Next page →


#435427

FromJohn S <Sophi.2@invalid.org>
Date2016-11-13 16:44 -0600
Message-ID<o0aq9v$vho$6@dont-email.me>
In reply to#435375
On 11/13/2016 12:07 PM, M Philbrook wrote:
> In article <o08sl9$ies$1@gonzo.alcatraz>, jasen@xnet.co.nz says...
>>
>> On 2016-11-13, John S <Sophi.2@invalid.org> wrote:
>>> On 11/12/2016 7:32 PM, pedro wrote:
>>>> On Sat, 12 Nov 2016 16:20:58 -0500, M Philbrook
>>>> <jamie_ka1lpa@charter.net> wrote:
>>>>
>>>>
>>>>> Yes, they have both a water generation plant and scott connection
>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>
>>>> Finally someone has mentioned Scott transformation.  Beat me to it!
>>>>
>>>
>>> But, according to Philbrick, two phase voltages are only 90 degrees
>>> apart. Three phases are 120 degrees apart. Please reconcile that
>>> discrepancy.
>>
>> Huh? That's what the scott transformer does.
>>
>> https://en.wikipedia.org/wiki/Scott-T_transformer
>
>  some people get easily confused.
>
>  Two phase motors were good because you can run the motor the direction
> you need without using a starter phase or capactor and on top of that
> get the standard utility voltages for other items, two legs worth plus
> common.

Maybe they were way back then. But you can dispense with the Scott-T and 
use a 3-phase motor to run in the direction you need. And you don't need 
a capactor (sic). Still 3 wires for a delta connection.

>  The 2 phase AC motor with slip ring motor to bring the rotor out for
> shorting via a rheostat was a good form a soft starting and speed
> regulation back then.

The same can be done with a 3 phase motor.

>  Later you could get 3 phase motors working the same way, then they came
> out with Eddy current clutches, AC tachs as feed back. TUBE amps for the
> eddy current coils with the AC tach as the feed back to generate the
> pinch off voltage on the grid ;)
>
>  I feel old.
>
> Jamie
>

[toc] | [prev] | [next] | [standalone]


#435436

Fromkrw <krw@somewhere.com>
Date2016-11-13 18:13 -0500
Message-ID<9psh2cdgtggi2cjn5r0ocf43o0fkr0c0nh@4ax.com>
In reply to#435259
On Sat, 12 Nov 2016 19:52:42 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/12/2016 7:32 PM, pedro wrote:
>> On Sat, 12 Nov 2016 16:20:58 -0500, M Philbrook
>> <jamie_ka1lpa@charter.net> wrote:
>>
>>
>>> Yes, they have both a water generation plant and scott connection
>>> transformers from commercial 3 phase to fill in when they need it.
>>
>> Finally someone has mentioned Scott transformation.  Beat me to it!
>>
>
>But, according to Philbrick, two phase voltages are only 90 degrees 
>apart. Three phases are 120 degrees apart. Please reconcile that 
>discrepancy.

Do know anything about electricity?  From any two (non-co linear)
phases, one can construct any other phase relationship.  That's the
function of the Scott-T.

[toc] | [prev] | [next] | [standalone]


#435258

FromJohn S <Sophi.2@invalid.org>
Date2016-11-12 19:48 -0600
Message-ID<o08gnb$33e$6@dont-email.me>
In reply to#435184
On 11/12/2016 3:20 PM, M Philbrook wrote:
> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>
>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>
>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>
>>>>>> really?
>>>>>>
>>>>>>  two leads 90 degree shift..
>>>>>
>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>> shift, smart ass?
>>>>
>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>> mains *now* doesn't mean he can't know what it is.
>>>>
>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>
>>>> Also, he didn't mention "mains" in that follow-up.
>>>>
>>>> Also, replying to pedantry with jackassery is lame.
>>>> (whereas the opposite is just plain fun ;-)
>>>
>>>  actually there is an old place near me that uses 2 phase power./
>>>
>>> Jamie
>>>
>>
>> Does the old place generate its own power? The power company does not
>> provide two phase power.
>
>  Yes, they have both a water generation plant and scott connection
> transformers from commercial 3 phase to fill in when they need it.
>
> Jamie
>

So it is not 2 phase, it is 3 phase with a lame connection.

Please explain how it is used without the fill-in. Two phase motors? 
Note that three phase is completely different from two phase. The phases 
are 120 degrees apart in 3 phase (with a common reference which requires 
3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires), 
even according to you. Why would they use a Scott-T when 3 phase is 
already available. Pretty stupid -- just like you.

If you don't believe me, set up a simple LTSpice schematic and run it. 
It will teach you things you obviously do not know.

[toc] | [prev] | [next] | [standalone]


#435260

Fromkrw <krw@somewhere.com>
Date2016-11-12 20:56 -0500
Message-ID<srhf2c9e3tl0kmb5t47u7b9655bdr5lsfq@4ax.com>
In reply to#435258
On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/12/2016 3:20 PM, M Philbrook wrote:
>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>
>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>
>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>
>>>>>>> really?
>>>>>>>
>>>>>>>  two leads 90 degree shift..
>>>>>>
>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>> shift, smart ass?
>>>>>
>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>
>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>
>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>
>>>>> Also, replying to pedantry with jackassery is lame.
>>>>> (whereas the opposite is just plain fun ;-)
>>>>
>>>>  actually there is an old place near me that uses 2 phase power./
>>>>
>>>> Jamie
>>>>
>>>
>>> Does the old place generate its own power? The power company does not
>>> provide two phase power.
>>
>>  Yes, they have both a water generation plant and scott connection
>> transformers from commercial 3 phase to fill in when they need it.
>>
>> Jamie
>>
>
>So it is not 2 phase, it is 3 phase with a lame connection.

No, he said 2-phase.  The Scott-T is used to transform three-phase, as
supplied by the power company, into the 2-phase this old installation
requires.
>
>Please explain how it is used without the fill-in. Two phase motors? 
>Note that three phase is completely different from two phase. The phases 
>are 120 degrees apart in 3 phase (with a common reference which requires 
>3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires), 
>even according to you. Why would they use a Scott-T when 3 phase is 
>already available. Pretty stupid -- just like you.

Because "he" needs two-phase and only three-phase is available from
the power company, thus the Scott-T.  He is pretty clear, here.
>
>If you don't believe me, set up a simple LTSpice schematic and run it. 
>It will teach you things you obviously do not know.

You should do some research.

[toc] | [prev] | [next] | [standalone]


#435264

FromJohn S <Sophi.2@invalid.org>
Date2016-11-12 20:10 -0600
Message-ID<o08i16$33e$8@dont-email.me>
In reply to#435260
On 11/12/2016 7:56 PM, krw wrote:
> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>
>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>
>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>
>>>>>>>> really?
>>>>>>>>
>>>>>>>>  two leads 90 degree shift..
>>>>>>>
>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>> shift, smart ass?
>>>>>>
>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>
>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>
>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>
>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>
>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>
>>>>> Jamie
>>>>>
>>>>
>>>> Does the old place generate its own power? The power company does not
>>>> provide two phase power.
>>>
>>>  Yes, they have both a water generation plant and scott connection
>>> transformers from commercial 3 phase to fill in when they need it.
>>>
>>> Jamie
>>>
>>
>> So it is not 2 phase, it is 3 phase with a lame connection.
>
> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
> supplied by the power company, into the 2-phase this old installation
> requires.
>>
>> Please explain how it is used without the fill-in. Two phase motors?
>> Note that three phase is completely different from two phase. The phases
>> are 120 degrees apart in 3 phase (with a common reference which requires
>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>> even according to you. Why would they use a Scott-T when 3 phase is
>> already available. Pretty stupid -- just like you.
>
> Because "he" needs two-phase and only three-phase is available from
> the power company, thus the Scott-T.  He is pretty clear, here.

What is the advantage of two phase power?

>> If you don't believe me, set up a simple LTSpice schematic and run it.
>> It will teach you things you obviously do not know.
>
> You should do some research.

I worked with single/three phase power mains for 17 years. I suggest you 
do some research as well. After that we can compare notes.

[toc] | [prev] | [next] | [standalone]


#435294

FromJasen Betts <jasen@xnet.co.nz>
Date2016-11-13 04:57 +0000
Message-ID<o08rrq$i8c$1@gonzo.alcatraz>
In reply to#435264
On 2016-11-13, John S <Sophi.2@invalid.org> wrote:
> On 11/12/2016 7:56 PM, krw wrote:
>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>> wrote:
>
> What is the advantage of two phase power?
>

It's perfect for running two phase motors, which were, I understand, 
an eariler invention than three phase motors.  If you've got antique
plant two phase might be useful.

-- 
This email has not been checked by half-arsed antivirus software 

[toc] | [prev] | [next] | [standalone]


#435306

Fromupsidedown@downunder.com
Date2016-11-13 11:07 +0200
Message-ID<5nag2c9me172gvriernkkh9594h7v1q4ga@4ax.com>
In reply to#435294
On 13 Nov 2016 04:57:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

>On 2016-11-13, John S <Sophi.2@invalid.org> wrote:
>> On 11/12/2016 7:56 PM, krw wrote:
>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>
>> What is the advantage of two phase power?
>>
>
>It's perfect for running two phase motors, which were, I understand, 
>an eariler invention than three phase motors.  If you've got antique
>plant two phase might be useful.

What is the difference between a two phase (90 degree)  motor and a
single phase motor with a starter winding, in which the starter
winding is powered by a capacitor from the single phase ? Is the
starter winding weaker ?

On a two phase motor with equal windings 90 degrees apart and with a
capacitor between the two winding hot ends and connecting the single
phase to either end of the capacitor will run the motor. Depending of
which capacitor end is connected to the phase, the motor runs either
CW or CCW. 

Is there a reason, why an inductance is used instead of capacitance to
achieve the 90 degree phase shift ?

[toc] | [prev] | [next] | [standalone]


#435346

FromJohn S <Sophi.2@invalid.org>
Date2016-11-13 09:57 -0600
Message-ID<o0a2eq$vho$1@dont-email.me>
In reply to#435294
On 11/12/2016 10:57 PM, Jasen Betts wrote:
> On 2016-11-13, John S <Sophi.2@invalid.org> wrote:
>> On 11/12/2016 7:56 PM, krw wrote:
>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>
>> What is the advantage of two phase power?
>>
>
> It's perfect for running two phase motors, which were, I understand,
> an eariler invention than three phase motors.  If you've got antique
> plant two phase might be useful.
>

Okay, it just stuck me that he is using his self-generated 2-phase power 
when possible, but then uses commercial 3-phase with a Scott-T to 
provide standby 2-phase power. I was thinking that he was applying three 
phase power to a 2-phase motor when not generating his own power.
My mistake.

[toc] | [prev] | [next] | [standalone]


#435437

Fromkrw <krw@somewhere.com>
Date2016-11-13 18:14 -0500
Message-ID<6ush2c173uqejf0a5kca0c04oqim5a3v1s@4ax.com>
In reply to#435264
On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/12/2016 7:56 PM, krw wrote:
>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>> wrote:
>>
>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>
>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>
>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>
>>>>>>>>> really?
>>>>>>>>>
>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>
>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>> shift, smart ass?
>>>>>>>
>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>
>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>
>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>
>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>
>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>
>>>>>> Jamie
>>>>>>
>>>>>
>>>>> Does the old place generate its own power? The power company does not
>>>>> provide two phase power.
>>>>
>>>>  Yes, they have both a water generation plant and scott connection
>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>
>>>> Jamie
>>>>
>>>
>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>
>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>> supplied by the power company, into the 2-phase this old installation
>> requires.
>>>
>>> Please explain how it is used without the fill-in. Two phase motors?
>>> Note that three phase is completely different from two phase. The phases
>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>> even according to you. Why would they use a Scott-T when 3 phase is
>>> already available. Pretty stupid -- just like you.
>>
>> Because "he" needs two-phase and only three-phase is available from
>> the power company, thus the Scott-T.  He is pretty clear, here.
>
>What is the advantage of two phase power?

It exists.
>
>>> If you don't believe me, set up a simple LTSpice schematic and run it.
>>> It will teach you things you obviously do not know.
>>
>> You should do some research.
>
>I worked with single/three phase power mains for 17 years. I suggest you 
>do some research as well. After that we can compare notes.

Turn your degree in now. 

[toc] | [prev] | [next] | [standalone]


#435578

Fromupsidedown@downunder.com
Date2016-11-14 21:19 +0200
Message-ID<rf2k2cpipq74j1s2c8jpog34ps1g32djv2@4ax.com>
In reply to#435437
On Sun, 13 Nov 2016 18:14:48 -0500, krw <krw@somewhere.com> wrote:

>On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>wrote:
>
>>On 11/12/2016 7:56 PM, krw wrote:
>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>>
>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>
>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>
>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>
>>>>>>>>>> really?
>>>>>>>>>>
>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>
>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>> shift, smart ass?
>>>>>>>>
>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>
>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>
>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>
>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>
>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>
>>>>>>> Jamie
>>>>>>>
>>>>>>
>>>>>> Does the old place generate its own power? The power company does not
>>>>>> provide two phase power.
>>>>>
>>>>>  Yes, they have both a water generation plant and scott connection
>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>
>>>>> Jamie
>>>>>
>>>>
>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>
>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>> supplied by the power company, into the 2-phase this old installation
>>> requires.
>>>>
>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>> Note that three phase is completely different from two phase. The phases
>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>> already available. Pretty stupid -- just like you.
>>>
>>> Because "he" needs two-phase and only three-phase is available from
>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>
>>What is the advantage of two phase power?
>
>It exists.

In Europe, I have never heard about 2 phase (90 degree) power. 

For instance the hydroelectric power station a few hundred meters from
where I live has been using 3 phase generators for at least 110 years.

Apparently any 2 phase feeds were US specific. When did they actually
generate 2 phase electricity and how long was it distributed ?

When did the production of 2 phase electricity ceased, how long did
they produce 2 phase motors ?

Pleaser correct me if I am wrong, but that has been more than a
century ago.

[toc] | [prev] | [next] | [standalone]


#435639

Fromkrw <krw@somewhere.com>
Date2016-11-14 19:54 -0500
Message-ID<r1nk2chvm907q5bfs1cj669f65qv2ofa8b@4ax.com>
In reply to#435578
On Mon, 14 Nov 2016 21:19:10 +0200, upsidedown@downunder.com wrote:

>On Sun, 13 Nov 2016 18:14:48 -0500, krw <krw@somewhere.com> wrote:
>
>>On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>>wrote:
>>
>>>On 11/12/2016 7:56 PM, krw wrote:
>>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>>> wrote:
>>>>
>>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>>
>>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>>
>>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>>
>>>>>>>>>>> really?
>>>>>>>>>>>
>>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>>
>>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>>> shift, smart ass?
>>>>>>>>>
>>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>>
>>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>>
>>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>>
>>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>>
>>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>>
>>>>>>>> Jamie
>>>>>>>>
>>>>>>>
>>>>>>> Does the old place generate its own power? The power company does not
>>>>>>> provide two phase power.
>>>>>>
>>>>>>  Yes, they have both a water generation plant and scott connection
>>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>>
>>>>>> Jamie
>>>>>>
>>>>>
>>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>>
>>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>>> supplied by the power company, into the 2-phase this old installation
>>>> requires.
>>>>>
>>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>>> Note that three phase is completely different from two phase. The phases
>>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>>> already available. Pretty stupid -- just like you.
>>>>
>>>> Because "he" needs two-phase and only three-phase is available from
>>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>>
>>>What is the advantage of two phase power?
>>
>>It exists.
>
>In Europe, I have never heard about 2 phase (90 degree) power.

Perhaps but Europe isn't the end-all. 

>For instance the hydroelectric power station a few hundred meters from
>where I live has been using 3 phase generators for at least 110 years.
>
>Apparently any 2 phase feeds were US specific. When did they actually
>generate 2 phase electricity and how long was it distributed ?
>
>When did the production of 2 phase electricity ceased, how long did
>they produce 2 phase motors ?

I've never seen one but I understand they were quite common for things
like elevators.
>
>Pleaser correct me if I am wrong, but that has been more than a
>century ago.

Sure but some installations still exist.

[toc] | [prev] | [next] | [standalone]


#435685

Fromupsidedown@downunder.com
Date2016-11-15 09:55 +0200
Message-ID<k6fl2chbck3knvv6489d2sg919hfnc8vl2@4ax.com>
In reply to#435639
On Mon, 14 Nov 2016 19:54:03 -0500, krw <krw@somewhere.com> wrote:

>>Apparently any 2 phase feeds were US specific. When did they actually
>>generate 2 phase electricity and how long was it distributed ?
>>
>>When did the production of 2 phase electricity ceased, how long did
>>they produce 2 phase motors ?
>
>I've never seen one but I understand they were quite common for things
>like elevators.

It is equally simple to switch the motor from CW to CCW by
interchanging two phases in a three phase system.

It is also easy to make  soft starter in a 3 phase system by starting
in wye and run in delta.

According to
https://openenergymonitor.org/emon/buildingblocks/3-phase-power
two phase was invented in1885 and three phases just two years later.

It is hard to believe that they had built o much two phase
infrastructure that they would continue building it, after the
superior three phase system was invented.

[toc] | [prev] | [next] | [standalone]


#435750

FromGlen Walpert <nospam@null.void>
Date2016-11-15 17:55 +0000
Message-ID<582b4c2a$0$7287$c3e8da3$66d3cc2f@news.astraweb.com>
In reply to#435685
On Tue, 15 Nov 2016 09:55:32 +0200, upsidedown wrote:

> On Mon, 14 Nov 2016 19:54:03 -0500, krw <krw@somewhere.com> wrote:
> 
>>>Apparently any 2 phase feeds were US specific. When did they actually
>>>generate 2 phase electricity and how long was it distributed ?
>>>
>>>When did the production of 2 phase electricity ceased, how long did
>>>they produce 2 phase motors ?
>>
>>I've never seen one but I understand they were quite common for things
>>like elevators.
> 
> It is equally simple to switch the motor from CW to CCW by interchanging
> two phases in a three phase system.
> 
> It is also easy to make  soft starter in a 3 phase system by starting in
> wye and run in delta.
> 
> According to
> https://openenergymonitor.org/emon/buildingblocks/3-phase-power two
> phase was invented in1885 and three phases just two years later.
> 
> It is hard to believe that they had built o much two phase
> infrastructure that they would continue building it, after the superior
> three phase system was invented.

40+ years ago I worked in a Philadelphia factory building which had a bit 
of two-phase wiring still in place which had last been used in the 1940's 
IIRC, and was considered obsolete long before then, with three-phase 
powering most equipment.  The building was reputed to have originally 
been the first indoor movie studio back when full sunlight was required, 
accounting for the greenhouse-like construction of 3 walls and the roof, 
which should give some indication of when the original two-phase power 
was installed.

Higher torque ripple, lower efficiency, needs 4 wires instead of 3, it is 
a wonder any of it lasted until the 1940's.

[toc] | [prev] | [next] | [standalone]


#435619

FromJohn S <Sophi.2@invalid.org>
Date2016-11-14 17:39 -0600
Message-ID<o0dhtj$ndk$1@dont-email.me>
In reply to#435437
On 11/13/2016 5:14 PM, krw wrote:
> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 11/12/2016 7:56 PM, krw wrote:
>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>>
>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>
>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>
>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>
>>>>>>>>>> really?
>>>>>>>>>>
>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>
>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>> shift, smart ass?
>>>>>>>>
>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>
>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>
>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>
>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>
>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>
>>>>>>> Jamie
>>>>>>>
>>>>>>
>>>>>> Does the old place generate its own power? The power company does not
>>>>>> provide two phase power.
>>>>>
>>>>>  Yes, they have both a water generation plant and scott connection
>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>
>>>>> Jamie
>>>>>
>>>>
>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>
>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>> supplied by the power company, into the 2-phase this old installation
>>> requires.
>>>>
>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>> Note that three phase is completely different from two phase. The phases
>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>> already available. Pretty stupid -- just like you.
>>>
>>> Because "he" needs two-phase and only three-phase is available from
>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>
>> What is the advantage of two phase power?
>
> It exists.

Where is it in use? Cite>


>>
>>>> If you don't believe me, set up a simple LTSpice schematic and run it.
>>>> It will teach you things you obviously do not know.
>>>
>>> You should do some research.
>>
>> I worked with single/three phase power mains for 17 years. I suggest you
>> do some research as well. After that we can compare notes.
>
> Turn your degree in now.

You first.


[toc] | [prev] | [next] | [standalone]


#435641

Fromkrw <krw@somewhere.com>
Date2016-11-14 19:55 -0500
Message-ID<v5nk2c5m97pdh7qbttnj887evek7vpchfh@4ax.com>
In reply to#435619
On Mon, 14 Nov 2016 17:39:05 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/13/2016 5:14 PM, krw wrote:
>> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>> wrote:
>>
>>> On 11/12/2016 7:56 PM, krw wrote:
>>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>>> wrote:
>>>>
>>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>>
>>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>>
>>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>>
>>>>>>>>>>> really?
>>>>>>>>>>>
>>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>>
>>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>>> shift, smart ass?
>>>>>>>>>
>>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>>
>>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>>
>>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>>
>>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>>
>>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>>
>>>>>>>> Jamie
>>>>>>>>
>>>>>>>
>>>>>>> Does the old place generate its own power? The power company does not
>>>>>>> provide two phase power.
>>>>>>
>>>>>>  Yes, they have both a water generation plant and scott connection
>>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>>
>>>>>> Jamie
>>>>>>
>>>>>
>>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>>
>>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>>> supplied by the power company, into the 2-phase this old installation
>>>> requires.
>>>>>
>>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>>> Note that three phase is completely different from two phase. The phases
>>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>>> already available. Pretty stupid -- just like you.
>>>>
>>>> Because "he" needs two-phase and only three-phase is available from
>>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>>
>>> What is the advantage of two phase power?
>>
>> It exists.
>
>Where is it in use? Cite>
>
>
>>>
>>>>> If you don't believe me, set up a simple LTSpice schematic and run it.
>>>>> It will teach you things you obviously do not know.
>>>>
>>>> You should do some research.
>>>
>>> I worked with single/three phase power mains for 17 years. I suggest you
>>> do some research as well. After that we can compare notes.
>>
>> Turn your degree in now.
>
>You first.
>
You're the one claiming to know something about power and perhaps even
work in the area but have been consistently wrong.  

[toc] | [prev] | [next] | [standalone]


#435620

FromJohn S <Sophi.2@invalid.org>
Date2016-11-14 17:46 -0600
Message-ID<o0dibb$ndk$2@dont-email.me>
In reply to#435437
On 11/13/2016 5:14 PM, krw wrote:
> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 11/12/2016 7:56 PM, krw wrote:
>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>>
>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>
>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>
>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>
>>>>>>>>>> really?
>>>>>>>>>>
>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>
>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>> shift, smart ass?
>>>>>>>>
>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>
>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>
>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>
>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>
>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>
>>>>>>> Jamie
>>>>>>>
>>>>>>
>>>>>> Does the old place generate its own power? The power company does not
>>>>>> provide two phase power.
>>>>>
>>>>>  Yes, they have both a water generation plant and scott connection
>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>
>>>>> Jamie
>>>>>
>>>>
>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>
>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>> supplied by the power company, into the 2-phase this old installation
>>> requires.
>>>>
>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>> Note that three phase is completely different from two phase. The phases
>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>> already available. Pretty stupid -- just like you.
>>>
>>> Because "he" needs two-phase and only three-phase is available from
>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>
>> What is the advantage of two phase power?
>
> It exists.

Now you are just being an argumentative ass. Many things exist that we 
do not use because they are not practical.

[toc] | [prev] | [next] | [standalone]


#435643

Fromkrw <krw@somewhere.com>
Date2016-11-14 19:56 -0500
Message-ID<28nk2c5eauhcgn7hkbs1r6b4rnv2emnd30@4ax.com>
In reply to#435620
On Mon, 14 Nov 2016 17:46:27 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/13/2016 5:14 PM, krw wrote:
>> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>> wrote:
>>
>>> On 11/12/2016 7:56 PM, krw wrote:
>>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>>> wrote:
>>>>
>>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>>
>>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>>
>>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>>
>>>>>>>>>>> really?
>>>>>>>>>>>
>>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>>
>>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>>> shift, smart ass?
>>>>>>>>>
>>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>>
>>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>>
>>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>>
>>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>>
>>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>>
>>>>>>>> Jamie
>>>>>>>>
>>>>>>>
>>>>>>> Does the old place generate its own power? The power company does not
>>>>>>> provide two phase power.
>>>>>>
>>>>>>  Yes, they have both a water generation plant and scott connection
>>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>>
>>>>>> Jamie
>>>>>>
>>>>>
>>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>>
>>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>>> supplied by the power company, into the 2-phase this old installation
>>>> requires.
>>>>>
>>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>>> Note that three phase is completely different from two phase. The phases
>>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>>> already available. Pretty stupid -- just like you.
>>>>
>>>> Because "he" needs two-phase and only three-phase is available from
>>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>>
>>> What is the advantage of two phase power?
>>
>> It exists.
>
>Now you are just being an argumentative ass. Many things exist that we 
>do not use because they are not practical.

Idiot.  They exist because they were practical.  

You didn't even know what a Scott-T was.  Turn in your degree now.

[toc] | [prev] | [next] | [standalone]


#435777

FromJohn S <Sophi.2@invalid.org>
Date2016-11-15 17:00 -0600
Message-ID<o0g403$do3$1@dont-email.me>
In reply to#435643
On 11/14/2016 6:56 PM, krw wrote:
> On Mon, 14 Nov 2016 17:46:27 -0600, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 11/13/2016 5:14 PM, krw wrote:
>>> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>>> wrote:
>>>
>>>> On 11/12/2016 7:56 PM, krw wrote:
>>>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>>>> wrote:
>>>>>
>>>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>>>
>>>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>>>
>>>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>>>
>>>>>>>>>>>> really?
>>>>>>>>>>>>
>>>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>>>
>>>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>>>> shift, smart ass?
>>>>>>>>>>
>>>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>>>
>>>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>>>
>>>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>>>
>>>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>>>
>>>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>>>
>>>>>>>>> Jamie
>>>>>>>>>
>>>>>>>>
>>>>>>>> Does the old place generate its own power? The power company does not
>>>>>>>> provide two phase power.
>>>>>>>
>>>>>>>  Yes, they have both a water generation plant and scott connection
>>>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>>>
>>>>>>> Jamie
>>>>>>>
>>>>>>
>>>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>>>
>>>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>>>> supplied by the power company, into the 2-phase this old installation
>>>>> requires.
>>>>>>
>>>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>>>> Note that three phase is completely different from two phase. The phases
>>>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>>>> already available. Pretty stupid -- just like you.
>>>>>
>>>>> Because "he" needs two-phase and only three-phase is available from
>>>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>>>
>>>> What is the advantage of two phase power?
>>>
>>> It exists.
>>
>> Now you are just being an argumentative ass. Many things exist that we
>> do not use because they are not practical.
>
> Idiot.  They exist because they were practical.

And how long ago was that, Idiot?

Sure. About 60 or so years ago. For a couple of years, maybe. Try buying 
2 phase power from the power company now. I know 2 phase power can be 
created with a Scott-T so you will have to buy 3 phase power first and 
then spend more money to create the Scott-T. What will that get you 
other than loss of money?


> You didn't even know what a Scott-T was.  Turn in your degree now.
>

An ass-umption of yours, dip-shit. Turn in your brain now. It has little 
to offer.

[toc] | [prev] | [next] | [standalone]


#435791

Fromkrw <krw@somewhere.com>
Date2016-11-15 19:20 -0500
Message-ID<7d9n2cthde7eq3rfcd12241kkgv94acci5@4ax.com>
In reply to#435777
On Tue, 15 Nov 2016 17:00:21 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 11/14/2016 6:56 PM, krw wrote:
>> On Mon, 14 Nov 2016 17:46:27 -0600, John S <Sophi.2@invalid.org>
>> wrote:
>>
>>> On 11/13/2016 5:14 PM, krw wrote:
>>>> On Sat, 12 Nov 2016 20:10:40 -0600, John S <Sophi.2@invalid.org>
>>>> wrote:
>>>>
>>>>> On 11/12/2016 7:56 PM, krw wrote:
>>>>>> On Sat, 12 Nov 2016 19:48:13 -0600, John S <Sophi.2@invalid.org>
>>>>>> wrote:
>>>>>>
>>>>>>> On 11/12/2016 3:20 PM, M Philbrook wrote:
>>>>>>>> In article <o07naa$33e$2@dont-email.me>, Sophi.2@invalid.org says...
>>>>>>>>>
>>>>>>>>> On 11/12/2016 11:03 AM, M Philbrook wrote:
>>>>>>>>>> In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>>>>>>>>>>>
>>>>>>>>>>> John S <Sophi.2@invalid.org> writes:
>>>>>>>>>>>>>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>>>>>>>>>>>>>> are common, but I have never encountered 2 phase.
>>>>>>>>>>>>>
>>>>>>>>>>>>> really?
>>>>>>>>>>>>>
>>>>>>>>>>>>>  two leads 90 degree shift..
>>>>>>>>>>>>
>>>>>>>>>>>> How often have you encountered a mains supply with 90 degree phase
>>>>>>>>>>>> shift, smart ass?
>>>>>>>>>>>
>>>>>>>>>>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>>>>>>>>>>> mains *now* doesn't mean he can't know what it is.
>>>>>>>>>>>
>>>>>>>>>>> Also, it's what stepper motors use, and we encounter those every day.
>>>>>>>>>>>
>>>>>>>>>>> Also, he didn't mention "mains" in that follow-up.
>>>>>>>>>>>
>>>>>>>>>>> Also, replying to pedantry with jackassery is lame.
>>>>>>>>>>> (whereas the opposite is just plain fun ;-)
>>>>>>>>>>
>>>>>>>>>>  actually there is an old place near me that uses 2 phase power./
>>>>>>>>>>
>>>>>>>>>> Jamie
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Does the old place generate its own power? The power company does not
>>>>>>>>> provide two phase power.
>>>>>>>>
>>>>>>>>  Yes, they have both a water generation plant and scott connection
>>>>>>>> transformers from commercial 3 phase to fill in when they need it.
>>>>>>>>
>>>>>>>> Jamie
>>>>>>>>
>>>>>>>
>>>>>>> So it is not 2 phase, it is 3 phase with a lame connection.
>>>>>>
>>>>>> No, he said 2-phase.  The Scott-T is used to transform three-phase, as
>>>>>> supplied by the power company, into the 2-phase this old installation
>>>>>> requires.
>>>>>>>
>>>>>>> Please explain how it is used without the fill-in. Two phase motors?
>>>>>>> Note that three phase is completely different from two phase. The phases
>>>>>>> are 120 degrees apart in 3 phase (with a common reference which requires
>>>>>>> 3 wires) whereas 2 phase is 90 degrees apart (also requiring 3 wires),
>>>>>>> even according to you. Why would they use a Scott-T when 3 phase is
>>>>>>> already available. Pretty stupid -- just like you.
>>>>>>
>>>>>> Because "he" needs two-phase and only three-phase is available from
>>>>>> the power company, thus the Scott-T.  He is pretty clear, here.
>>>>>
>>>>> What is the advantage of two phase power?
>>>>
>>>> It exists.
>>>
>>> Now you are just being an argumentative ass. Many things exist that we
>>> do not use because they are not practical.
>>
>> Idiot.  They exist because they were practical.
>
>And how long ago was that, Idiot?

It doesn't matter, moron (only morons capitalize words in the middle
of sentences).  It exists, when you _still_ maintain that it doesn't.
Not only that, you believed that you can't convert from 3-phase to
2-phase with a passive device.  As I said, turn in your degree!
>
>Sure. About 60 or so years ago. For a couple of years, maybe. Try buying 
>2 phase power from the power company now. I know 2 phase power can be 
>created with a Scott-T so you will have to buy 3 phase power first and 
>then spend more money to create the Scott-T. What will that get you 
>other than loss of money?

Completely irrelevant.  You can't buy DC from the power company,
either.

>
>
>> You didn't even know what a Scott-T was.  Turn in your degree now.
>>
>
>An ass-umption of yours, dip-shit. Turn in your brain now. It has little 
>to offer.

Not an assumption at all, asshole.  You were told about it many times
and still said it was impossible.  Turn in your degree now!

[toc] | [prev] | [next] | [standalone]


#435159

Fromupsidedown@downunder.com
Date2016-11-12 20:53 +0200
Message-ID<2boe2cl811jf287k4jhr0t5sb85f32hqst@4ax.com>
In reply to#435117
On Sat, 12 Nov 2016 12:03:33 -0500, M Philbrook
<jamie_ka1lpa@charter.net> wrote:

>In article <xn60nt2y7f.fsf@delorie.com>, dj@delorie.com says...
>> 
>> John S <Sophi.2@invalid.org> writes:
>> >>> 2 phase? Please educate me on this. I know that single phase and 3 phase
>> >>> are common, but I have never encountered 2 phase.
>> >>
>> >> really?
>> >>
>> >>  two leads 90 degree shift..
>> >
>> > How often have you encountered a mains supply with 90 degree phase
>> > shift, smart ass?
>> 
>> Nikolas Tesla invented it long ago.  Just because it isn't used for
>> mains *now* doesn't mean he can't know what it is.
>> 
>> Also, it's what stepper motors use, and we encounter those every day.
>> 
>> Also, he didn't mention "mains" in that follow-up.
>> 
>> Also, replying to pedantry with jackassery is lame.
>> (whereas the opposite is just plain fun ;-)
>
> actually there is an old place near me that uses 2 phase power./
>
>Jamie

The problem with a single phase feed is that the motor doesn't into
which direction (CW/CCW) it should start. Once started, it will
continue in that direction.

One way to solve this problem is to feed an auxiliary winding at 90
degree offset from a different phase conductor. Requires 3 conductors.

However, with a local starter capacitor, the auxiliary winding can be
fed with a 90 phase, so no need to for a separate auxiliary phase
conductor.


If you are going to use multiple phases, use three phases with 120
degree shifts. Since the phase currents will cancel in Neutral, there
is no need for a separate Neutral connector. Just use a delta
connection with three phase conductors.  This is much more effective
than 2 phases + Neutral.
 

[toc] | [prev] | [next] | [standalone]


Page 2 of 3 — ← Prev page 1 [2] 3  Next page →

Back to top | Article view | sci.electronics.design


csiph-web