Odd wiring in tube ampmschematics

[Ralph Mowery]

In article <3b79c1d4-e2f1-4c21-aa2b-6dce04c4a468@googlegroups.com>,
tabbypurr@gmail.com says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

You should have seen the problem some jack leg caused where I worked. A
3 phase 480 volt 20 amp circuit. The power came in one electrical box
and going out of that to another box about 3 feet away. For some reason
the person doing the wiring ran 2 legs through one piece of connecting
conduit and the other wire through another piece of conduit. Sort of
made it into a transformer with a shorted turn. Really heated things
up.

 

[Ron D.]

t.....r@gmail.com says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:

The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding).. It can also be zero, but not likely,

The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.

 

[Phil Allison]

Ron D. wrote:

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:

** Fraid it is a yep.

Any mains appliance returns the same current down the neutral conductor it drew from the active. This mean very little mag field is generated by the appliance's own lead, assuming the two wires are closely paired or twisted.



.... Phil

 

[Ralph Mowery]

In article <137d918d-cb77-4a4f-989b-66c8d7dbe141@googlegroups.com>,
pallison49@gmail.com says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:


** Fraid it is a yep.

Any mains appliance returns the same current down the neutral conductor it drew from the active. This mean very little mag field is generated by the appliance's own lead, assuming the two wires are closely paired or twisted.

I think you all are compairing apples and oranges.

One is thinking of a 240 volt system with 2 hots and the neutral, whrere
the neutral can have almost any ammount of current on it up to being
equal to what one side of the hot is using (120 volt devices).

Phil and the other are probably talking about a 120 volt device that has
only a hot and neutral. Which in that case the neutral must have the
same ammount of cuttent as the hot wire, unless there is a problem.

 

[Fox's Mercantile]

On 12/9/18 3:14 PM, Ralph Mowery wrote:

One is thinking of a 240 volt system with 2 hots and the neutral, whrere
the neutral can have almost any ammount of current on it up to being
equal to what one side of the hot is using (120 volt devices).

This is one of fallacies here in Ranger.
Around here, the thought is the Neutral to the breaker panel from
the meter can be smaller because it's not going to carry ALL of the
current because there will be an offsetting current from the other
hot leg.

They also tend to under size everything, because, you know, copper
is expensive. For example, my house has a 200 Amp service.
That should be #000 on all three legs and #4 for the ground.
When I got here, it was two #4 on the hots, #6 on the neutral and
#10 for the ground.
That was one of the first things I fixed.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Ralph Mowery]

In article <DMqdnZNXDrKSCJDBnZ2dnUU7-I3NnZ2d@giganews.com>,
jdangus@att.net says...

This is one of fallacies here in Ranger.
Around here, the thought is the Neutral to the breaker panel from
the meter can be smaller because it's not going to carry ALL of the
current because there will be an offsetting current from the other
hot leg.

They also tend to under size everything, because, you know, copper
is expensive. For example, my house has a 200 Amp service.
That should be #000 on all three legs and #4 for the ground.
When I got here, it was two #4 on the hots, #6 on the neutral and
#10 for the ground.
That was one of the first things I fixed.

Well you do not have to worry about ice forming on the power wires. I
think one chart showed about 105 deg C for the temperature rise with the
# 4 wire at around 200 amps.

 

[Clifford Heath]

On 10/12/18 8:14 am, Ralph Mowery wrote:

In article <137d918d-cb77-4a4f-989b-66c8d7dbe141@googlegroups.com>,
pallison49@gmail.com says...


All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:


** Fraid it is a yep.

Any mains appliance returns the same current down the neutral conductor it drew from the active. This mean very little mag field is generated by the appliance's own lead, assuming the two wires are closely paired or twisted.




I think you all are compairing apples and oranges.

One is thinking of a 240 volt system with 2 hots and the neutral, whrere
the neutral can have almost any ammount of current on it up to being
equal to what one side of the hot is using (120 volt devices).

Phil and the other are probably talking about a 120 volt device that has
only a hot and neutral. Which in that case the neutral must have the
same ammount of cuttent as the hot wire, unless there is a problem.

Phil lives in Sydney. We use 240V single phase wiring, with a single hot
and a single neutral grounded at the panel. The RCD protection trips if
the currents on hot and neutral differ, even by milliamps for milliseconds.

Some (few) buildings have two separate 240V phases wired to different
circuits inside the house, but nothing gets connected between the phases.

Clifford Heath.

 

[Phil Allison]

Ralph Mowery wrote:

Nope:


** Fraid it is a yep.

Any mains appliance returns the same current down the neutral
conductor it drew from the active. This mean very little mag field
is generated by the appliance's own lead, assuming the two wires
are closely paired or twisted.



I think you all are compairing apples and oranges.

One is thinking of a 240 volt system with 2 hots and the neutral, whrere
the neutral can have almost any ammount of current on it up to being
equal to what one side of the hot is using (120 volt devices).

** If a 240V load is connected across the two phases, then the current is each wire is the same.

The principle is simple: a current carrying loop that is closed down on itself ( ie the wires are paralleled) or twisted cannot radiate a mag field.


..... Phil

 

On Sunday, 9 December 2018 19:14:44 UTC, Ron D. wrote:

tabby says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:

The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding). It can also be zero, but not likely,

The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.

I think you'll find house sockets are wired single phase.


NT

 

[Fox's Mercantile]

On 12/10/18 4:04 AM, tabbypurr@gmail.com wrote:

On Sunday, 9 December 2018 19:14:44 UTC, Ron D. wrote:
tabby says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:

The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding). It can also be zero, but not likely,

The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.


I think you'll find house sockets are wired single phase.


NT

Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the +/- nature of it.
It is not, the primary is single phase.

The real problem occurs in a 3-phase Wye system.
A-N, B-N and C-N are each 120 volts. Until someone who doesn't know
how it works, takes A-B and tells the consumer it's 240v. And then
typically table saws go up in flames, because they REALLY do no like
running at 208 volts with a 120 instead of 180 phase shift across
the windings.




--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Look165]

120*(3^^0.5) gives 207V, not 240.

Fox's Mercantile a Êcrit :

On 12/10/18 4:04 AM, tabbypurr@gmail.com wrote:
On Sunday, 9 December 2018 19:14:44 UTC, Ron D.  wrote:
tabby says...

All domestic mains current loads are balanced, ie live & neutral
carry the same & opposite current, resulting in nearly zero
magnetic field. Pacemakers, like any life-critical medical
equipment, are designed & tested to meet harsh real-world
conditions & keep going.

Nope:

The neutral carries the "difference current" in the legs of a split
phase system.  It can be 180 or -180 out of phase (Said for ease of
understanding).  It can also be zero, but not likely,

The "difference current" is more accurate.  While voltage is usually
sinusoidal, current doesn't have to be.  Voltage is what's regulated.
inductive loads are one matter, but laptop switching power supplies
is another.


I think you'll find house sockets are wired single phase.


NT


Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the +/- nature of it.
It is not, the primary is single phase.

The real problem occurs in a 3-phase Wye system.
A-N, B-N and C-N are each 120 volts. Until someone who doesn't know
how it works, takes A-B and tells the consumer it's 240v. And then
typically table saws go up in flames, because they REALLY do no like
running at 208 volts with a 120 instead of 180 phase shift across
the windings.

 

On Monday, 10 December 2018 11:42:17 UTC, Fox's Mercantile wrote:

On 12/10/18 4:04 AM, tabbypurr wrote:
On Sunday, 9 December 2018 19:14:44 UTC, Ron D. wrote:
tabby says...

All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.

Nope:

The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding). It can also be zero, but not likely,

The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.


I think you'll find house sockets are wired single phase.


NT


Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the +/- nature of it.
It is not, the primary is single phase.

3 phase has an angle between each phase of 360/3 = 120 degrees.
2 phase has an angle between each phase of 360/2 = 180 degrees. And that's what you have with the US domestic 120/240 system.

The real problem occurs in a 3-phase Wye system.
A-N, B-N and C-N are each 120 volts. Until someone who doesn't know
how it works, takes A-B and tells the consumer it's 240v. And then
typically table saws go up in flames, because they REALLY do no like
running at 208 volts with a 120 instead of 180 phase shift across
the windings.

Naturally some people don't understand some things, nothing new there.


NT

 

[Fox's Mercantile]

On 12/10/18 6:01 AM, Look165 wrote:
> 120*(3^^0.5) gives 207V, not 240.

207.84 or commonly called 208.

I said uneducated electricians THINK that two 120v phases
running 120 degrees instead of 180 degrees apart equals
240 volts.

As a service manager in a tool store, I had to explain that
running a 5 HP table saw motor on 208 volts was NOT covered
under warranty and they should make their "electrician" pay
for the repairs.

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Fox's Mercantile]

On 12/10/18 6:22 AM, tabbypurr@gmail.com wrote:

On Monday, 10 December 2018 11:42:17 UTC, Fox's Mercantile wrote:
Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the Âą nature of it.
It is not, the primary is single phase.

3 phase has an angle between each phase of 360/3 = 120 degrees.

Correct.

2 phase has an angle between each phase of 360/2 = 180 degrees.
And that's what you have with the US domestic 120/240 system.

Absolutely NOT. That is center tapped single phase.
In the early days of electrical generation, there was 2-phase, but the
two phases were offset by 90 degrees.

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

On Monday, 10 December 2018 16:58:22 UTC, Fox's Mercantile wrote:

On 12/10/18 6:22 AM, tabbypurr wrote:
On Monday, 10 December 2018 11:42:17 UTC, Fox's Mercantile wrote:

Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the Âą nature of it.
It is not, the primary is single phase.

3 phase has an angle between each phase of 360/3 = 120 degrees.

Correct.

2 phase has an angle between each phase of 360/2 = 180 degrees.
And that's what you have with the US domestic 120/240 system.

Absolutely NOT. That is center tapped single phase.

It's one of the 3 phase distribution system's phases, centre tapped, that is its source. That does not change the fact that it's 2 phase.

In the early days of electrical generation, there was 2-phase, but the
two phases were offset by 90 degrees.

I've read various times of 2 phase systems with 180 degree offset, but not seen 90 degrees.


NT

 

[pfjw@aol.com]

OK - I am in an unique position here: I actually have worked with true 2-phase power, developed in the 1920s before 3-phase was well-established, as a means to provide off-set to start motors. Also pretty much confined to Philadelphia and Baltimore, being the two major cities in what became the PMJ Interconnect.

From PECO Tariffs:

Two-phase power is where the two phases are 90° apart.

This is a four (4) wire system, and the neutral currents do not cancel even if the system is in balance. Hence the need for four (4) wires.

I am surprised that so many went after the remark of audio and pacemakers. But here goes:

Pacemakers will accept all sorts of RF and other interference today - a vast improvement from the days when merely walking past a vintage microwave (in operation) would cause troubles.

But the modern pacemaker/defibrillators do not like stray currents in the body, as they may be taken as an event. If there is as much as a few volts difference between the NEUTRAL and the GROUND, and an individual so-equipped steps into that difference, that could be enough to trip the defib-function. Not (usually)fatal, but quite painful. Just ask the guy up on the 10th floor designing temporary artificial hearts - between restoring vintage Porsches. He will talk the paint off a board if given a chance - and I am sufficiently intrigued by what he does to give him those chances.

And, of course, there are hum-loops caused by stray currents.

Peter Wieck
Melrose Park, PA

 

[Ralph Mowery]

In article <2b63acc6-9213-497b-9eba-dfd2a61663e8@googlegroups.com>,
tabbypurr@gmail.com says...

3 phase has an angle between each phase of 360/3 = 120 degrees.
2 phase has an angle between each phase of 360/2 = 180 degrees. And that's what you have with the US domestic 120/240 system.


The real problem occurs in a 3-phase Wye system.
A-N, B-N and C-N are each 120 volts. Until someone who doesn't know
how it works, takes A-B and tells the consumer it's 240v. And then
typically table saws go up in flames, because they REALLY do no like
running at 208 volts with a 120 instead of 180 phase shift across
the windings.

Naturally some people don't understand some things, nothing new there.

Some do not understand that by definition and the way it is generated, 2
phase power is 90 deg out of phase, not 180.

There for in the US the common feed of 240 and 120 volts can not be 2
phase.

https://en.wikipedia.org/wiki/Two-phase_electric_power