Reply by Joerg April 25, 20162016-04-25
On 2016-04-25 07:23, Ralph Barone wrote:
> Joerg <news@analogconsultants.com> wrote: >> On 2016-04-22 15:21, Jon Elson wrote: >>> Joerg wrote: >>> >>> >>>> SWER? That's only used in the more remote places of Australia and NZ. >>>> Not here. It's always two-phase or three-phase via wires. >>>> >>> As far as I know, they don't use HV hot-hot much for residential. Most of >>> the transformers have one HV terminal, and the housing is the ground return >>> for the HV. I have seen in a FEW places transformers that had 2 HV >>> terminals. These might have been on the truck for use in open delta setups, >>> and that is all they had when they needed one for a repair. >>> >>> Our whole neighborhood is all single phase feed, one hot HV wire with a big >>> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >>> The 45 KV feeds a substaion a mile or so away. >>> >> >> Weird. I walk our dogs every morning here in Cameron Park (California) >> so today I double-checked: All transformers have two HV terminals. Most >> of my walking route is along streets that have three HV phases along the >> poles and the transformers are connected "round-robin" style to equalize >> the load, each between two phases. Then there are small HV tap offs to >> some clusters of homes with only two phases. But same transformers with >> two HV prongs. >> >> Larger businesses have 3-phase transformers with three HV terminals. >> >> Our utility is PG&E. Running a fourth wire for neutral somehow doesn't >> make sense from a cost POV. So they don't. > > PG&E may connect their distribution transformers phase to phase, but I > assure you that many others connect them phase to ground. >
Can't remember having see those. The ones I know look like this, even in Europe: https://en.wikipedia.org/wiki/Distribution_transformer#/media/File:240v_transformer_-_geograph.org.uk_-_1062014.jpg -- Regards, Joerg http://www.analogconsultants.com/
Reply by Joerg April 25, 20162016-04-25
On 2016-04-24 14:21, Hul Tytus wrote:
> Joerg - have you had any luck finding harmonics charactoristic of power > line transformers? >
No, we'll just be going after 60Hz for now but the system will be adaptable to doing 60Hz and 180Hz, allowing our own experiments. [...] -- Regards, Joerg http://www.analogconsultants.com/
Reply by Ralph Barone April 25, 20162016-04-25
Joerg <news@analogconsultants.com> wrote:
> On 2016-04-22 15:21, Jon Elson wrote: >> Joerg wrote: >> >> >>> SWER? That's only used in the more remote places of Australia and NZ. >>> Not here. It's always two-phase or three-phase via wires. >>> >> As far as I know, they don't use HV hot-hot much for residential. Most of >> the transformers have one HV terminal, and the housing is the ground return >> for the HV. I have seen in a FEW places transformers that had 2 HV >> terminals. These might have been on the truck for use in open delta setups, >> and that is all they had when they needed one for a repair. >> >> Our whole neighborhood is all single phase feed, one hot HV wire with a big >> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >> The 45 KV feeds a substaion a mile or so away. >> > > Weird. I walk our dogs every morning here in Cameron Park (California) > so today I double-checked: All transformers have two HV terminals. Most > of my walking route is along streets that have three HV phases along the > poles and the transformers are connected "round-robin" style to equalize > the load, each between two phases. Then there are small HV tap offs to > some clusters of homes with only two phases. But same transformers with > two HV prongs. > > Larger businesses have 3-phase transformers with three HV terminals. > > Our utility is PG&E. Running a fourth wire for neutral somehow doesn't > make sense from a cost POV. So they don't.
PG&E may connect their distribution transformers phase to phase, but I assure you that many others connect them phase to ground.
Reply by Hul Tytus April 24, 20162016-04-24
Joerg - have you had any luck finding harmonics charactoristic of power 
line transformers?

Hul

Joerg <news@analogconsultants.com> wrote:
> On 2016-04-23 20:01, legg wrote: > > On Sat, 23 Apr 2016 09:46:52 -0700, Joerg <news@analogconsultants.com> > > wrote: > > > >> On 2016-04-22 15:21, Jon Elson wrote: > >>> Joerg wrote: > >>> > >>> > >>>> SWER? That's only used in the more remote places of Australia and NZ. > >>>> Not here. It's always two-phase or three-phase via wires. > >>>> > >>> As far as I know, they don't use HV hot-hot much for residential. Most of > >>> the transformers have one HV terminal, and the housing is the ground return > >>> for the HV. I have seen in a FEW places transformers that had 2 HV > >>> terminals. These might have been on the truck for use in open delta setups, > >>> and that is all they had when they needed one for a repair. > >>> > >>> Our whole neighborhood is all single phase feed, one hot HV wire with a big > >>> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. > >>> The 45 KV feeds a substaion a mile or so away. > >>> > >> > >> Weird. I walk our dogs every morning here in Cameron Park (California) > >> so today I double-checked: All transformers have two HV terminals. Most > >> of my walking route is along streets that have three HV phases along the > >> poles and the transformers are connected "round-robin" style to equalize > >> the load, each between two phases. Then there are small HV tap offs to > >> some clusters of homes with only two phases. But same transformers with > >> two HV prongs. > >> > >> Larger businesses have 3-phase transformers with three HV terminals. > >> > >> Our utility is PG&E. Running a fourth wire for neutral somehow doesn't > >> make sense from a cost POV. So they don't. > > > > Neutrals are only developed at the final LV (<630V) stage. > >
> Jon was talking about the HV side, transformers with just one HV > terminal. There you either need an extra HV neutral or SWER.
> -- > Regards, Joerg
> http://www.analogconsultants.com/
Reply by Joerg April 24, 20162016-04-24
On 2016-04-24 08:15, legg wrote:
> On Sun, 24 Apr 2016 07:05:32 -0700, Joerg <news@analogconsultants.com> > wrote: > >> On 2016-04-23 20:01, legg wrote: >>> On Sat, 23 Apr 2016 09:46:52 -0700, Joerg <news@analogconsultants.com> >>> wrote: >>> >>>> On 2016-04-22 15:21, Jon Elson wrote: >>>>> Joerg wrote: >>>>> >>>>> >>>>>> SWER? That's only used in the more remote places of Australia and NZ. >>>>>> Not here. It's always two-phase or three-phase via wires. >>>>>> >>>>> As far as I know, they don't use HV hot-hot much for residential. Most of >>>>> the transformers have one HV terminal, and the housing is the ground return >>>>> for the HV. I have seen in a FEW places transformers that had 2 HV >>>>> terminals. These might have been on the truck for use in open delta setups, >>>>> and that is all they had when they needed one for a repair. >>>>> >>>>> Our whole neighborhood is all single phase feed, one hot HV wire with a big >>>>> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >>>>> The 45 KV feeds a substaion a mile or so away. >>>>> >>>> >>>> Weird. I walk our dogs every morning here in Cameron Park (California) >>>> so today I double-checked: All transformers have two HV terminals. Most >>>> of my walking route is along streets that have three HV phases along the >>>> poles and the transformers are connected "round-robin" style to equalize >>>> the load, each between two phases. Then there are small HV tap offs to >>>> some clusters of homes with only two phases. But same transformers with >>>> two HV prongs. >>>> >>>> Larger businesses have 3-phase transformers with three HV terminals. >>>> >>>> Our utility is PG&E. Running a fourth wire for neutral somehow doesn't >>>> make sense from a cost POV. So they don't. >>> >>> Neutrals are only developed at the final LV (<630V) stage. >>> >> >> >> Jon was talking about the HV side, transformers with just one HV >> terminal. There you either need an extra HV neutral or SWER. > > ...and you weren't. >
Sure I was. -- Regards, Joerg http://www.analogconsultants.com/
Reply by legg April 24, 20162016-04-24
On Sun, 24 Apr 2016 07:05:32 -0700, Joerg <news@analogconsultants.com>
wrote:

>On 2016-04-23 20:01, legg wrote: >> On Sat, 23 Apr 2016 09:46:52 -0700, Joerg <news@analogconsultants.com> >> wrote: >> >>> On 2016-04-22 15:21, Jon Elson wrote: >>>> Joerg wrote: >>>> >>>> >>>>> SWER? That's only used in the more remote places of Australia and NZ. >>>>> Not here. It's always two-phase or three-phase via wires. >>>>> >>>> As far as I know, they don't use HV hot-hot much for residential. Most of >>>> the transformers have one HV terminal, and the housing is the ground return >>>> for the HV. I have seen in a FEW places transformers that had 2 HV >>>> terminals. These might have been on the truck for use in open delta setups, >>>> and that is all they had when they needed one for a repair. >>>> >>>> Our whole neighborhood is all single phase feed, one hot HV wire with a big >>>> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >>>> The 45 KV feeds a substaion a mile or so away. >>>> >>> >>> Weird. I walk our dogs every morning here in Cameron Park (California) >>> so today I double-checked: All transformers have two HV terminals. Most >>> of my walking route is along streets that have three HV phases along the >>> poles and the transformers are connected "round-robin" style to equalize >>> the load, each between two phases. Then there are small HV tap offs to >>> some clusters of homes with only two phases. But same transformers with >>> two HV prongs. >>> >>> Larger businesses have 3-phase transformers with three HV terminals. >>> >>> Our utility is PG&E. Running a fourth wire for neutral somehow doesn't >>> make sense from a cost POV. So they don't. >> >> Neutrals are only developed at the final LV (<630V) stage. >> > > >Jon was talking about the HV side, transformers with just one HV >terminal. There you either need an extra HV neutral or SWER.
...and you weren't. RL
Reply by Joerg April 24, 20162016-04-24
On 2016-04-23 20:01, legg wrote:
> On Sat, 23 Apr 2016 09:46:52 -0700, Joerg <news@analogconsultants.com> > wrote: > >> On 2016-04-22 15:21, Jon Elson wrote: >>> Joerg wrote: >>> >>> >>>> SWER? That's only used in the more remote places of Australia and NZ. >>>> Not here. It's always two-phase or three-phase via wires. >>>> >>> As far as I know, they don't use HV hot-hot much for residential. Most of >>> the transformers have one HV terminal, and the housing is the ground return >>> for the HV. I have seen in a FEW places transformers that had 2 HV >>> terminals. These might have been on the truck for use in open delta setups, >>> and that is all they had when they needed one for a repair. >>> >>> Our whole neighborhood is all single phase feed, one hot HV wire with a big >>> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >>> The 45 KV feeds a substaion a mile or so away. >>> >> >> Weird. I walk our dogs every morning here in Cameron Park (California) >> so today I double-checked: All transformers have two HV terminals. Most >> of my walking route is along streets that have three HV phases along the >> poles and the transformers are connected "round-robin" style to equalize >> the load, each between two phases. Then there are small HV tap offs to >> some clusters of homes with only two phases. But same transformers with >> two HV prongs. >> >> Larger businesses have 3-phase transformers with three HV terminals. >> >> Our utility is PG&E. Running a fourth wire for neutral somehow doesn't >> make sense from a cost POV. So they don't. > > Neutrals are only developed at the final LV (<630V) stage. >
Jon was talking about the HV side, transformers with just one HV terminal. There you either need an extra HV neutral or SWER. -- Regards, Joerg http://www.analogconsultants.com/
Reply by legg April 23, 20162016-04-23
On Sat, 23 Apr 2016 09:46:52 -0700, Joerg <news@analogconsultants.com>
wrote:

>On 2016-04-22 15:21, Jon Elson wrote: >> Joerg wrote: >> >> >>> SWER? That's only used in the more remote places of Australia and NZ. >>> Not here. It's always two-phase or three-phase via wires. >>> >> As far as I know, they don't use HV hot-hot much for residential. Most of >> the transformers have one HV terminal, and the housing is the ground return >> for the HV. I have seen in a FEW places transformers that had 2 HV >> terminals. These might have been on the truck for use in open delta setups, >> and that is all they had when they needed one for a repair. >> >> Our whole neighborhood is all single phase feed, one hot HV wire with a big >> insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. >> The 45 KV feeds a substaion a mile or so away. >> > >Weird. I walk our dogs every morning here in Cameron Park (California) >so today I double-checked: All transformers have two HV terminals. Most >of my walking route is along streets that have three HV phases along the >poles and the transformers are connected "round-robin" style to equalize >the load, each between two phases. Then there are small HV tap offs to >some clusters of homes with only two phases. But same transformers with >two HV prongs. > >Larger businesses have 3-phase transformers with three HV terminals. > >Our utility is PG&E. Running a fourth wire for neutral somehow doesn't >make sense from a cost POV. So they don't.
Neutrals are only developed at the final LV (<630V) stage. RL
Reply by Joerg April 23, 20162016-04-23
On 2016-04-22 18:53, legg wrote:
> On Tue, 19 Apr 2016 12:29:26 -0400, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> On 04/19/2016 12:19 PM, Cydrome Leader wrote: >>> Joerg <news@analogconsultants.com> wrote: >>>> On 2016-04-18 15:02, Lasse Langwadt Christensen wrote: >>>>> Den mandag den 18. april 2016 kl. 23.50.56 UTC+2 skrev legg: >>>>>> On Mon, 18 Apr 2016 07:58:30 -0700, Joerg <news@analogconsultants.com> >>>>>> wrote: >>>>>> >>>>>>> On 2016-04-18 07:57, legg wrote: >>>>>>>> On Sun, 17 Apr 2016 17:16:12 -0700 (PDT), George Herold >>>>>>>> <gherold@teachspin.com> wrote: >>>>>>>> >>>>>>>>> On Sunday, April 17, 2016 at 4:54:36 PM UTC-4, Joerg wrote: >>>>>>>>>> Folks, >>>>>>>>>> >>>>>>>>>> A system needs to be able to detect whether a pole transformer has >>>>>>>>>> failed and stopped feeding power to a pump. The transformer will be >>>>>>>>>> 100ft or more away. The detection has to work even without any power >>>>>>>>>> flow meaning we can only detect the presence of a 60Hz electric field >>>>>>>>>> that leaks from the various boxs such as a breaker box. >>>>>>>>>> >>>>>>>>>> In order not to get fooled by 60Hz from other overhead lines I was >>>>>>>>>> wondering if classic pole transformers generate enough 3rd and 5th >>>>>>>>>> harmonics to distinguish the field emanating from secondary wires from >>>>>>>>>> that coming from overhead HV lines. Does anyone know where to find info >>>>>>>>>> about that? >>>>>>>>>> >>>>>>>>>> -- >>>>>>>>>> Regards, Joerg >>>>>>>>>> >>>>>>>>>> http://www.analogconsultants.com/ >>>>>>>>> >>>>>>>>> Magneto-striction causes the transformer to vibrate at 120 Hz, >>>>>>>>> I don't know if you could sense that. >>>>>>>>> >>>>>>> >>>>>>> Audio buzz isn't reliable here because the transformer will be far away. >>>>>>> All we have is any E-field leaking out from conduit and the breaker box. >>>>>>> The good thing is, we can be right at the breaker box, just not in it. >>>>>>> >>>>>>> >>>>>>>>> George H. >>>>>>>> >>>>>>>> Transformers can fail and still buzz. >>>>>>>> >>>>>>>> There are many reasons why a pump might fail. Expending effort at >>>>>>>> sensing just a single one of these is misdirected. >>>>>>>> >>>>>>> >>>>>>> No, it is not. The fact that transformer or HV line failure is by far >>>>>>> the highest concern in this application is based on clear statistical >>>>>>> evidence. >>>>>>> >>>>>> I'd like to see THOSE statistics. >>>>>> >>>>>> You're trying to see if a pump is functional, when it's not supposed >>>>>> to be running. Does this make sense to you? >>>>> >>>>> if it is, say, a pump to keep a basement from flooding or some cows from >>>>> going thirsty it makes perfect sense to get an electrician out to fix the >>>>> power before it is needed >>>>> >>>> >>>> Bingo! >>> >>> No. It costs too much to hire electricians. The problem will have to fix >>> itself. >>> >>> >> If you're the farmer or building owner, it's reasonable. On the other >> hand, if you're selling gizmos that will on average save several hundred >> dollars' worth of wasted time every few years, you can charge more for >> your gizmo. >> >> Everybody wins. What's not to like? >> >> Cheers >> >> Phil Hobbs > > Sounds more like low-labor corporate or absentee owner situation. > If it involved livestock, or even just irrigation, you'd need more > operating info than just the power being present at a pump. >
As I've said, such information is already being furnished. This whole topic is about furnishing an additional bit of information, mains power failure. Without needing an electrician to come out for the install.
> You could sell it to somebody at the corporate level - it doesn't have > to make sense, if you convince them it will 'on average save......'. >
It's not about big corp products either. -- Regards, Joerg http://www.analogconsultants.com/
Reply by Joerg April 23, 20162016-04-23
On 2016-04-22 15:21, Jon Elson wrote:
> Joerg wrote: > > >> SWER? That's only used in the more remote places of Australia and NZ. >> Not here. It's always two-phase or three-phase via wires. >> > As far as I know, they don't use HV hot-hot much for residential. Most of > the transformers have one HV terminal, and the housing is the ground return > for the HV. I have seen in a FEW places transformers that had 2 HV > terminals. These might have been on the truck for use in open delta setups, > and that is all they had when they needed one for a repair. > > Our whole neighborhood is all single phase feed, one hot HV wire with a big > insulator, and then a ground. The main street has 7200 V and 45 KV 3-phase. > The 45 KV feeds a substaion a mile or so away. >
Weird. I walk our dogs every morning here in Cameron Park (California) so today I double-checked: All transformers have two HV terminals. Most of my walking route is along streets that have three HV phases along the poles and the transformers are connected "round-robin" style to equalize the load, each between two phases. Then there are small HV tap offs to some clusters of homes with only two phases. But same transformers with two HV prongs. Larger businesses have 3-phase transformers with three HV terminals. Our utility is PG&E. Running a fourth wire for neutral somehow doesn't make sense from a cost POV. So they don't. -- Regards, Joerg http://www.analogconsultants.com/