what does RST stand for  in electrical three phase system?
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Possibly Rectangular Series Transformer (RST).  See Page 7 of the link.
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A "delta" is a Greek letter often represented as a small triangle with three equal sides.  The letter "Y" has three arms.  Electric power is distributed by a system that uses three wires (or phases) which you can see atop most power poles or high tension cross-country power lines.\n\nWhen any one wire is conducted to ground (perhaps through a light bulb) the voltage is 110V.  When any two wires are connected and grounded (perhaps through a clothes dryer or kitchen range) the voltage is 220V which delivers far more power.  When all three wires are connected and grounded (perhaps through a large motor in a machine shop) the voltage is 440V and maximum power can be delivered.\n\nPower is delivered as alternating current (AC) because it can make transformers and other electromagnetic devices (certain motors) work where direct current would fail.\n\nTherefore, motors (and transformers) that handle all three wires or phases at 440V need circuitry with three separate windings.  Electrical engineers refer to the two methods of wiring (or diagraming) as "delta wound" or "Y wound."\n\nInterestingly, AC current increases from zero to positive to zero to negative and back to zero forming a sinusoid.  In three-phase current the peaks are offset (out of phase) so that there will always exist a voltage difference between each of the phases that can deliver power.
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It is a step down transformer.\nNs/Np = 6/220\nwhere Ns is the number of turns in the secondary and Np is the number of turns in the primary.
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Are you talking about Distribution transformers ? Then that 3-phase transf. becomes free floating, which means the 'nutral' line receives ALL the phases WITHOUT nutralising them to the Earth reference potential (Standard 0 volts) and hence all the SINGLE PHASE equipment connected to power will experience the 3-phase voltage (up to 440 volts) rather than single phase (about 230 volts). You know what it will do. In case of single phase transformers, and looking at most common load-connection configurations, not much will happen. But you may find more interference on the electronic equipment connected to it.
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R, S and T as consecutive letters are used to name the 3 different phases. I am not sure why they those 3 have been chosen.
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Control bits - indicate what is present in the packet. Details as follows: \n  SYN: The SYN bit indicates a synchronization segment is present. \n  ACK: The ACK bit indicates the acknowledgment number in the header is valid.\n  RST: The RST bit indicates the packet is a reset segment.
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For the three contacts in a plug which are detailed below.\n\nLive\nThe live contact carries alternating current. The voltage varies by country, as set by national regulations and industry standards. In a few cases (older installations in Scandinavian countries, the outputs of British 110 V building site isolation transformers and probably a few other cases) both main conductors may be live, either being two phases from a three-phase system or being from a single-phase transformer with centre-tapped output. Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarised plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarised plug. Furthermore even if live and neutral can only mate one way round it may be common to wire them without regard for which is which.\n\n\nNeutral\nThe neutral contact is in most (but not all) cases referenced to the earth. Except under fault conditions it generally does not pose a danger, but is nevertheless treated as live in most installation practices.\n\nThe main danger that can be posed by the neutral is it has a non-null voltage (possibly as high as the voltage on the mains line) after a broken neutral cable in the wiring. Neutral and earth (ground) are strongly related (see Ground (power)) and are usually connected at some point. However extra connections between the Neutral and the Ground must not be made unless the relevant jurisdiction's regulations allow it.\n\n\nEarth\nThe earth contact is only intended to carry current when connected to equipment that has developed an insulation fault (except for EMI/RFI filters which do cause a small current down the earth). If a bare live wire or live component in a device gets loose and touches the metal casing of the appliance, somebody touching the case may receive an electric shock. In many countries devices with metal cases must have the case connected to the ground connection. This reduces but does not eliminate the voltage present on the case relative to earth and metalwork connected to the earthing system.\n\nWhen the neutral is directly connected to the earth as part of the wiring system (a TN system) a fault to earth is a short circuit and therefore provided the wiring is done correctly the circuit breaker will open, or the fuse will blow. In the case of an indirect connection (via the body of the earth) between the earth and the neutral (a TT system) the resistance of the path is much higher and therefore a residual-current device (RCD) must normally be used to disconnect the fault.\n\nThe neutral core could in theory be used as a ground, but this would be dangerous if the core broke, so this is not normally used in building wiring or portable appliances. It is, however, used in some other situations with special precautions. For instance, in Switzerland, sockets in houses with the old two wire installation have the ground and neutral contacts connected together, probably supposing, that the professionally maintained house installation is much more reliable than plugged-in device. Also using the neutral as a ground prevents the use of RCDs.
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WYE connections reference the line values of current and voltage to a "hard-wired" neutral. This means  \n (line voltage) = 1.732 * (phase voltage)\n (line current) = (phase current)\nThis is a much easier system to use when manufacturing an electric machine ... there will be a "neutral" - complete with leads - that can be used when troubleshooting.\n\nDELTA connections reference the line values of current and voltage to a "theoretical" neutral. This means \n (phase voltage) = (line voltage)\n (phase current) = (line current) / 1.732\nBecause of the "theoretical" nature of the neutral connection, the winding can experience far harsher effects from harmonics than the standard WYE version. Thus it isn't used as often in large machines ... although it's fairly common in smaller (<100 HP) designs.\n\nAny 3-phase machine can be used in either format; in fact, most multi-speed windings employ one of each.\n\nThe simplest advantage may come when looking at transformers, though. With a WYE-DELTA transformer, there is no possibility of ground faults between the input and output sides (unless, of course, a major accident happens!). IT also has an immediate 1.732 ratio in terms of voltage/current ... even if the turn count is the same on both sides.
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Regular derailleurs have the cable slack in the high (smallest gear) rear position. Rapid rise are opposite- the derailleur is at rest on the largest rear cog.\n\nSTI stands for Shimano Total Integration. I think all Shimano components are STI, provided you use the recommended component groups..you can't use LX shifters with XTR, for example.
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the device is called a phase sequence indicator.  you connect it to the leads of the motor and rotate it and it will tell you the sequencing of the phases
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The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power.\n\nExplanation\n\nIn a purely resistive AC circuit, voltage and current waveforms are in step, changing polarity at the same instant in each cycle. Where reactive loads are present, such as capacitors or inductors, energy storage in the loads result in a time difference between the current and voltage waveforms. Since this stored energy returns to the source and is not available to do work at the load, a circuit with a low power factor will have higher currents to transfer a given quantity of power than a circuit with a high power factor.\n\nReal power is the capacity of the circuit for performing work in a particular time. Due to reactive elements of the load, the apparent power, which is the product of the voltage and current in the circuit, will be equal to or greater than the real power. The reactive power is a measure of the stored energy that is reflected to the source during each alternating current cycle.\n\nAC power flow has the three components: real power (P), measured in watts (W); apparent power (S), measured in volt-amperes (VA); and reactive power (Q), measured in reactive volt-amperes (VAr).\n\nThe power factor can be expressed as:\nP/S\nIn the case of a perfectly sinusoidal waveform, P, Q and S can be expressed as vectors that form a vector triangle such that:\nS*S=P*P+Q*Q\n\nBy definition, the power factor is a dimensionless number between 0 and 1. When power factor is equal to 0, the energy flow is entirely reactive, and stored energy in the load returns to the source on each cycle. When the power factor is 1, all the energy supplied by the source is consumed by the load. Power factors are usually stated as "leading" or "lagging" to show the sign of the phase angle.\n\nThe power factor is determined by the type of loads connected to the power system. These can be\n\nResistive \nInductive \nCapacitive \nIf a purely resistive load is connected to a power supply, current and voltage will change polarity in phase, the power factor will be unity (1), and the electrical energy flows in a single direction across the network in each cycle. Inductive loads such as transformers and motors (any type of wound coil) generate reactive power with current waveform lagging the voltage. Capacitive loads such as capacitor banks or buried cable generate reactive power with current phase leading the voltage. Both types of loads will absorb energy during part of the AC cycle, only to send this energy back to the source during the rest of the cycle.\n\nFor example, to get 1 kW of real power if the power factor is unity, 1 kVA of apparent power needs to be transferred (1 kVA = 1 kW × 1). At low values of power factor, more apparent power needs to be transferred to get the same real power. To get 1 kW of real power at 0.2 power factor 5 kVA of apparent power needs to be transferred (1 kW = 5 kVA × 0.2).\n\nIt is often possible to adjust the power factor of a system to very near unity. This practice is known as power factor correction and is achieved by switching in or out banks of inductors or capacitors. For example the inductive effect of motor loads may be offset by locally connected capacitors.\n\nEnergy losses in transmission lines increase with increasing current. Where a load has a power factor lower than 1, more current is required to deliver the same amount of useful energy. Power companies therefore require that customers, especially those with large loads, maintain the power factors of their respective loads within specified limits or be subject to additional charges. Engineers are often interested in the power factor of a load as one of the factors that affect the efficiency of power transmission.\n\n\nNon-sinusoidal components\n\n\nIn circuits having only sinusoidal currents and voltages, the power factor effect arises only from the difference in phase between the current and voltage. Th
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DC series wound motors and generators are the same thing. One you apply mechanical power to and you will get a rippled DC wave form out. The more commutator bars (or magnets) there are the less ripple you get.\nAlternators (generators) are like you find on a car and in the generator sets that power the world. They have rings that go all the way ring the armature instead of the slits in commutators. This means that as the armature spins through the fields of the magnetic an alternating current is induced through the winding and out through the two rings. This is better for the transmission of power over distances rather than DC. So two rings are single phase, three rings are three phase. \nThe difference in a car is that after the AC is produced a set of diodes rectify the current and then a regulator levels it to 13.8volts DC cause batteries dont like AC.
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The deciding factor here would be the Utility Company Service Entrance. THAT cannot be rewired by you! The other two points ( Low side of transformer and Motor Windings) can easily be configured either way by simply rewiring the 3 windings on the motor, and the 3 windings on the output of the transformer.\n\nOptimum efficiency will be DELTA-DELTA-DELTA or STAR-STAR-STAR...Either way no 'ground loops' to cause loss.
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Electicity in a commercial application is 3 phase, residential electricity is single phase
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I've found a good site introducing and explaining the voltage and phase relationships between delta and wye 3 phase transformers. Try www.elec-toolbox.com/usefulinfo/xfmr-3ph.htm\nI hope that this proves useful for your research.
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IEEE 829 - Test Procedure Specification (TPS)\n\n\n...did you SEE the memo about the new cover sheet?
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http://www.worldwidewords.org/qa/qa-thr1.htm\n\nhttp://www.bartleby.com/59/4/threesheetst.html