Australian electrical system

[<ramrod]

We have a power system that is 240 volts single phase or 415 volts 3 phase.

The mains in the street have 4 wires, 3 x 240 volts (active) and a neutral. Between each of the 240 volt wires is 415 volts and between the 240 volt active and the neutral is 240 volts.

Most modern homes are supplied with an 80 amp 2 cable system IE 240 volts.

If the current draw is greater than that and no 3 phase motors are installed then they can run 2 actives (phases) in and a neutral.

There are no transformers in these homes for the power supply, they just run some things off one active and some things off the other active.

If the load is too great for this 2 phase set up or you have one or more 3 phase motors then they will connect up 3 phases to your home (3 actives and a neutral) The power outlets are to be balanced over the 2 or 3 phases.

Power outlets in the homes are rated at 10 amps (2,400 watts) there are also available 15 amp outlets (3,600 watts) and 20 amp outlets (4,800 watts) although most homes do only have the 10 amp outlets. All outlets are earthed, and the current regulations require the earth and neutral to be joined in the fuse box.

The way the power outlets are configures is that a 10 plug will fit into a

10 amp, a 15 amp and 20 amp outlet, a 15 amp plug will fit into a 15 amp and a 20 outlet while 20 amp plug will only fit into a 20 outlet.

There are 30 amp outlets, but there are very rare and in general and equipment using a lot of power, is wired direct into an isolation switch and not an outlet.

Here on the 240 volt systems the active is red or brown, the neutral is black or blue and the earth is green and yellow (striped).

[Grumpy]

Thanks for explanation! However I work across USA, Europe and Ireland trouble shooting Environmental test chambers (Climate change units) but I have never come across as ridicules set up as that. Good luck my friend

We have a power system that is 240 volts single phase or 415 volts 3 phase.

The mains in the street have 4 wires, 3 x 240 volts (active) and a neutral. Between each of the 240 volt wires is 415 volts and between the 240 volt active and the neutral is 240 volts.

Most modern homes are supplied with an 80 amp 2 cable system IE 240 volts.

If the current draw is greater than that and no 3 phase motors are installed then they can run 2 actives (phases) in and a neutral.

There are no transformers in these homes for the power supply, they just run some things off one active and some things off the other active.

If the load is too great for this 2 phase set up or you have one or more 3 phase motors then they will connect up 3 phases to your home (3 actives and a neutral) The power outlets are to be balanced over the 2 or 3 phases.

Power outlets in the homes are rated at 10 amps (2,400 watts) there are also available 15 amp outlets (3,600 watts) and 20 amp outlets (4,800 watts) although most homes do only have the 10 amp outlets. All outlets are earthed, and the current regulations require the earth and neutral to be joined in the fuse box.

The way the power outlets are configures is that a 10 plug will fit into a 10 amp, a 15 amp and 20 amp outlet, a 15 amp plug will fit into a 15 amp and a 20 outlet while 20 amp plug will only fit into a 20 outlet.

There are 30 amp outlets, but there are very rare and in general and equipment using a lot of power, is wired direct into an isolation switch and not an outlet.

Here on the 240 volt systems the active is red or brown, the neutral is black or blue and the earth is green and yellow (striped).

[<ramrod]

Ø Thanks for explanation! However I work across USA, Europe and Ireland trouble shooting Ø Environmental test chambers (Climate change units) but I have never come across as Ø ridicules set up as that. Good luck my friend.

Just curios, what part of the set-up do you find ridicules?

[Grumpy]

[<ramrod]

Ø You have indicated that you have 4 wires' ( two hot one neutral and one ground)

We were talking about power wiring and so I did not include the earth (ground) as there is no earth (ground) in the street wiring, with the exception of ultra high voltage pylons that have a lightning (earth or ground) protection above ultra high voltage cables.

I said :-

//We have a power system that is 240 volts single phase or 415 volts 3 phase.

The mains in the street have 4 wires, 3 x 240 volts (active) and a neutral. Between each of the 240 volt wires is 415 volts and between the 240 volt active and the neutral is 240 volts.\\

Ø I can not figure out how are you getting 240 and 415 from same source???

The voltage is generated and here we use delta to wye transformers for power supply, which delivers 415 volts 3 phase and 240 volts single phase.

Delta-wye transformer

In this case I guess they are quoting some US voltages, but the single phase to 3 phase is not doubled.

//Phase to neutral Phase to phase

120 208

230 400\\

[Daniel who wants to know]

The same way we get 120/208 here in the USA, the 2 legs are phased 120° apart, not 180°, hence the 2 don?t fully add together. Stealing from answers.com:

First, consider single-phase 120/240 service like you would find in a house. the two hot wires are said to be 'in phase'. Think of it this way. Imagine a ruler 12 inches long. Put your finger on the six inch mark, the center. How far to each end? Six inches. Both ends are on the same line, just in opposite directions. So if you go six inches one way, and six inches the other way, the total distance is 12 inches.

120/240 volt systems are like that voltage-wise. The middle of the ruler is the neutral, and each end is a hot wire. When one hot leg is going positive, at the exact same time (that's the 'in phase' part) the other leg is going negative. Same line only opposite directions, like our ruler. So the two 120 volt legs just add up to 240. Now, here's the important part. Since one leg goes positive while the other leg goes negative, they are said to be 180 degrees apart, 360 degrees making up one complete AC cycle (2 X 180 = 360). In three phase power, there are, not two, but THREE hot wires. Since there are three, they can no longer be 180 degrees apart. They are 120 degrees apart (3 X 120 = 360). So, when phase A peaks, phase B has not yet peaked. it is at some intermediate voltage between zero and maximum. The two phases cannot just be added up because of this fact. Back to our ruler. Break the ruler in half. bend the two halves so the ruler is no longer straight (180 degrees) but bent at an angle of 120 degrees. Draw a line from end to end. See how we have formed a triangle? See also that the line we drew is not 12 inches long, but is shorter (the two ends are closer together)? That's why the voltages in a three phase system do not appear to add up. Lets make our ruler 240 inches long. If we bend it into the 120 degree angle and measure end-to-end, we will find the length to be about 208 inches, not 240! In a 120/208 three-phase system, each hot leg (phase) measures 120 volts to ground, BUT phase-to-phase measures 208 volts. This is true whether you measure A to B, B to C, or C to A. The math guys call this a vector sum. The vector is the angle at which the phases are in relation to each other (120 degrees) and the sum is the distance between the two bent ends (phases). To figure the phase-to-phase voltage, multiply the phase-to-neutral voltage by 1.73 (the square root of 3). Thus: 120 X 1.73 = 208, 277 X 1.73 = 480, etc. To figure the reverse, divide the phase-to-phase voltage by 1.73. Thus: 480 / 1.73 = 277, 208 / 1.73 = 120, etc. You trig people see how this relates to our triangle example using the cosine rule.

It should be noted that the use of the term phase above, as in "phase to phase" is not strictly correct, although a common usage. Each hot conductor in a 3-phase system is correctly called a "line", so the correct terminology would be "line to line", "line to neutral", etc.

[Grumpy]

not 180°, hence the 2 don't fully add

the two hot wires are said to be 'in

six inch mark, the center. How far to

directions. So if you go six inches one way,

the neutral, and each end is a hot wire.

phase' part) the other leg is going

volt legs just add up to 240.

leg goes negative, they are said to be 180

three phase power, there are, not two,

apart. They are 120 degrees apart (3 X

intermediate voltage between zero and

is no longer straight (180 degrees) but

formed a triangle? See also that the

together)? That's why the voltages in a

and measure end-to-end, we will find the

hot leg (phase) measures 120 volts to

measure A to B, B to C, or C to A.

phases are in relation to each other (120

1.73 (the square root of 3). Thus: 120

1.73 = 277, 208 / 1.73 = 120, etc.

phase" is not strictly correct, although a

"line", so the correct terminology would be

It seems that we have misunderstanding out side on the pol 4 wires 415 Voltage Ground, neutral and two hot or (Active), how do you get 120 from that without transformer?

[Congoleum Breckenridge]

They don't use 120v in Australia.

[Grumpy]

OK how do you get 220 from 415

[<ramrod]

Read my reply again we use 240 volts in Australia for household current and we use 415 volts for commercial and domestic 3 phase motors.

We do not use 110, 120, or 400 volts here.

We do not have mains transformers in the houses.

We run in either 240 volts or 415 volts (2 or 3 phase) into the homes, the extra phases only if require by load or for use of 3 phase motors.

By far the majority of homes only have 240 volts, as these days the mains coming in to a home have 80 amp cables coming in.

So 80 amps x 240 volts gives you around 19200 watts, quite a bit of power, almost 20 Kw.

I explained to you about the sub station transformers that give you 240 volts., read it again.

This 3 phase system is also used in most of Europe and UK with a slight variation in voltages.

Again a list of overseas voltages.

If you do not understand then it is beyond you capabilities or are you just stirring?

============================

From a previous note to Grumpy

The voltage is generated and here we use delta to wye transformers for power supply, which delivers 415 volts 3 phase and 240 volts single phase.

Delta-wye transformer

In this case I guess they are quoting some US voltages, but the single phase to 3 phase is not doubled.

//Phase to neutral Phase to phase

120 208

230 400\\

--------------------------------------

[Grumpy]

We have a power system that is 240 volts single phase or 415 volts 3 phase.

(The mains in the street have 4 wires, 3 x 240 volts (active) and a neutral. Between each of the 240 volt wires is 415 volts and between the 240 volt active and the neutral is 240 volts. ) Problem is here you have 480/3/50 to get 240 each leg, this is what I am sking where are you getting 415 from?

Most modern homes are supplied with an 80 amp 2 cable system IE 240 volts.

If the current draw is greater than that and no 3 phase motors are installed then they can run 2 actives (phases) in and a neutral.

There are no transformers in these homes for the power supply, they just run some things off one active and some things off the other active.

If the load is too great for this 2 phase set up or you have one or more 3 phase motors then they will connect up 3 phases to your home (3 actives and a neutral) The power outlets are to be balanced over the 2 or 3 phases.

Power outlets in the homes are rated at 10 amps (2,400 watts) there are also available 15 amp outlets (3,600 watts) and 20 amp outlets (4,800 watts) although most homes do only have the 10 amp outlets. All outlets are earthed, and the current regulations require the earth and neutral to be joined in the fuse box.

The way the power outlets are configures is that a 10 plug will fit into a 10 amp, a 15 amp and 20 amp outlet, a 15 amp plug will fit into a 15 amp and a 20 outlet while 20 amp plug will only fit into a 20 outlet.

There are 30 amp outlets, but there are very rare and in general and equipment using a lot of power, is wired direct into an isolation switch and not an outlet.

Here on the 240 volt systems the active is red or brown, the neutral is black or blue and the earth is green and yellow (striped).

[<ramrod]

Ø Problem is here you have 480/3/50 to get 240 each leg, this is what I am sking where are you Ø getting 415 from?

You ask where the 415 volts comes from, well it comes from generators and transformers. That is street and sub station transformers, as we do not have main transformers in the homes.

You have been told the transformers are delta to wye (star) to produce 415 volts 3 phase and 240 volts single phase.

Delta-wye transformer

In this case I guess they are quoting some US voltages, but the single phase to 3 phase is not doubled.

Phase to neutral Phase to phase

120 208

230 400

[Grumpy]