What is Phase?

Question

I work as an estimator(junior) for a mechanical company and I price a lot of equipment. I would like to learn more about the equipment that I am pricing. Can someone please give me a detailed description of what Phase is? I usually see this word in the equipment schedule. For instance it would have information on a Pump and it would tell me the Volts, Power and Phase.

thank you,

Answer 1

Three-phase electric power is a common method of electric power transmission.[1] It is a type of polyphase system mainly used to power motors and many other devices. A three-phase system uses less conductor material to transmit electric power than equivalent single-phase, two-phase, or direct-current systems at the same voltage.



In a three-phase system, three circuit conductors carry three alternating currents (of the same frequency) which reach their instantaneous peak values at different times. Taking one conductor as the reference, the other two currents are delayed in time by one-third and two-thirds of one cycle of the electrical current. This delay between "phases" has the effect of giving constant power transfer over each cycle of the current, and also makes it possible to produce a rotating magnetic field in an electric motor.



Three phase systems may or may not have a neutral wire. A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection).



Three phase has properties that make it very desirable in electric power systems. First, the phase currents tend to cancel out one another, summing to zero in the case of a linear balanced load. This makes it possible to eliminate the neutral conductor on some lines; all the phase conductors carry the same current and so can be the same size, for a balanced load. Second, power transfer into a linear balanced load is constant, which helps to reduce generator and motor vibrations. Finally, three-phase systems can produce a magnetic field that rotates in a specified direction, which simplifies the design of electric motors. Three is the lowest phase order to exhibit all of these properties.



Most domestic loads are single phase. In North America and some other countries, three phase power generally does not enter domestic houses at all. Even in areas where it does, it is typically split out at the main distribution board.



The three phases are typically indicated by colors which vary by country.

Answer 2

In simple way:



Power normally is generated by 3 phases,,why not 4 or 5 phases!

coz the 3 phase gives a balance means each phase carries the same value of current ( ideally) and the voltage between each phase shall be equal.



so for large loads we normally use 3 phase voltage , and since this load consumes huge of kilowatts then ,,increase the voltage of this equipment n reduce the consumed current ..P=VI

u have 2 read more of real n reactive power n about delta / y connections if u r interested



for small load u ll notice that most of them are using single phase .. (means connecting the equipment with one phase and neutral which results a less voltage than the three phase voltage)

Answer 3

Certainly. I switched to Disturbed a while back, and I've stayed with them for quite a while now. I've always had lesser bands, such as Three Days Grace, Breaking Benjamin, Seether, 3 Doors Down, etc, but Disturbed has always been the top dog. We also have song phases, in other words - until that band comes out with a better song than the last.

Answer 4

Phase refers to electrical hook ups. It gets more complicated than this if you want to go into electrical theory as it relates to wave phases, but that is not necessary for what you do. You simply need to know what phase the equipment is. Usually your bigger power drawing equipment is 3 phase. I would expect you would see something about the apms too, unless this is what you mean by power.

Answer 5

A phase is one point or portion in a recurring series of changes. Phase or phases may also refer to:



[edit] In science and engineering



* Phase (matter), a physically distinctive form of a substance, such as the solid, liquid, and gaseous states of ordinary matter

* The initial condition of a cyclic phenomenon

o Phase (waves), initial angle of a sinusoid function at its origin

o Continuous Fourier transform, angle of a complex coefficient representing the phase of one sinusoidal component

* The current (time varying) state of a cyclic phenomenon

o Lunar phase, the appearance of the Moon as viewed from the Earth

o Planetary phase, the appearance of the illuminated section of a planet

o Instantaneous phase, generalization for both cyclic and non-cyclic phenomena

* Phase factor, a complex scalar in the context of quantum mechanics

* Polyphase system, a means of distributing alternating current electric power in multiple conducting wires with definite phase offsets

o Single-phase electric power

o Three-phase electric power Basics of three-phase electric power

o Three-phase Mathematics of three-phase electric power

* In biology, a part of the cell cycle in which cells divide and reproduce

* Phaser (effect), an audio effect.

* Archaeological phase, a discrete period of occupation at an archaeological site.

http://en.wikipedia.org/wiki/Phase