how do i figure out phase a,b, and c of a 3 phase 115 VAC 400 Hz sys. if the wires not labled or color coded?
80787
it shouldnt mater that much, 3 phase power fires one after another, if all three have the same voltage, amperage, and Hz. the only thing, that i can think of, is to make sure that they are cycling in order. DO NOT CONECT TO MOTOR, if the motor is conected and the wires are conected in the improper order, it will not run backwards, it will cause severe damage, as far as i know. runing backwards would only work in 2 Phase power, Maby. Be carefull when using multi-meters with 3 Phase power, i read on my meter that that source can be unpredictable and very dangerous. A good meter and good judgement can do a lot of help in this situation. I think that if you just guess and hook them all up, and be ready to turn it off quickly, then if it is incorect you just switch your b and c wires and it should work. if you have a meter i think that some power setups have the a and b lines at 115vac and c is higher, MABY! i do not know for sure how to discover for sure what they are, but i dont think that ossiliscopes are the corect tool for the job. good luck
1175058
When the panel cools to the dew point, condensation can cause short circuits between phases. It is necessary to have condensation heaters operating in MCCs and PCCs.\nI always specify 100W condensation heaters operating at half voltage ie. Specify 220V heaters and connect them to 120V. This will ensure long life and a lower surface temperature.\n\nSource: 50 years Electrical engineering experience
1085514
The max sytem load for 3 phase 208v Y 30kva 100% 89 Amps, so buy a 100 amp this will give you  an upgrade if ever needed and be safe.
275873
The Heath AC voltmeter is illustrated in the link.  Click on the diagram to enlarge it.
868551
Well, you see, that isn't done.  When you need single phase power, you use only one phase of the supply circuit.  Each of the phases of the 480 volt 3 phase power will be run through a separate transformer to step the supply down into 3 phases at 120 volt.  Typically, a house is served by two of those three phases.  You use two phases with two hot wires and a neutral to get 240 volt power for your oven, range, dryer and water heater.  The other circuits in the house are served by one phase or the other at 120 volts with one hot wire and a neutral wire.
851608
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.
117712
I am trying to get the answer to the same question. I guess you're in com 110 too. I am stumped on it.
123099
I still trying to figure out it's voltage, sorry. ;-) I try to look.  5.5x10 to the 14th power Hz   http://www.cs.williams.edu/~cs105/f01/text/ch3/DigitalTrans_14.html    Then scroll down until you find Prism.
374724
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
71357
Volts-drop test.\n\nPut the armature on a V-block powered by a regulated voltage source.  Check the voltage across 2 adjacent com segments and repeat as you rotate thru 360 degrees.  They should all be the same.
702129
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.
398806
here is one of the datasheets available on the internet:\nhttp://www.ee.washington.edu/stores/DataSheets/74ls/74ls73.pdf
409039
Just google the IC number + datasheet and you should be able to find the data sheets for most of those components.  If you read the sheet properly, it will tell you what the internal circuit is.
459399
You must understand power in = power out.\nSo the P(in) = 200A * 240V = 48000Watts \nTherefore, to obtain 400A out put you will sacrifice the voltage which will = 48000/400 = 120V\nYou need a heavy duty Transformer which will handle the 400A. The wiring size is 500MCM wire. Which is usually bus bar in a cabinet.\n\nTypically 240V 3phase line to line on a delta-wye Xfmr can provide 208V line-line provides 120V line-neutral. (208/sqrt3)\n \nUnless you have a Xfmr to convert, another way would be to use an active inverter, IGBT controlled.
615599
Operating 60Hz appliances at 50Hz or viceversa may result in excessive heat buildup in transformers or in certain types of electric motors. \nIf you wish to safely operate 115V 60Hz appliances at 115V 50Hz then the following steps can be attempted: \n\nContact the manufacturer of the appliance. It may be possible to safely operate at 50Hz with the manufacturer's approval. \n\nSee if an alternate 240V 50Hz or 115V 50Hz power supply or electrical motor is available. Some manufacturers sell the same appliance or electric tool in many countries around the world and may be able to retrofit the power supply or electrical motor to 240V 50Hz. Some regions of Japan have 100V 50Hz supplies while others have 100V 60Hz supplies so it is not uncommon for Japanese manufactured electrical devices to have 50Hz solutions. \n\nIt is possible to purchase 60Hz sine wave power systems that take 240V 50Hz on input and produce 115V 60Hz on output. These solutions are generally very expensive, and it is usually more cost effective just to replace the tool or appliance. See here for a high current frequency conversion solution. \nIf these solutions, for one reason or another, do not work then there are only two further choices: dispose of the appliance or tool, or attempt to operate the appliance or tool at 50Hz and in the process potentially create a situation where the power supply or the motors in the appliance or tool are rendered non-operational.
742046
For three phase AC powered loads, three separate power lines provide power to the load. The voltage waveforms on these three lines differ only in their timing, or phase relationship. A fourth wire may provide a neutral connection to the load. In the case of balanced loads, where the current in each of the three phases is equal, the current in the neutral wire will be zero. The neutral wire may therefore be eliminated, as it is not necessary for the purpose of carrying current. The vector sum of the currents drawn from the three phase lines will be zero with a balanced load. A non-zero sum of the current indicates an unbalanced load and that a current is returning to the generator, or current source, via an unintended path. This is the ground fault current.\n\nThe ground fault current for a three-phase system, without neutral, may be measured by performing a vector summation of the phase currents. This summation may be performed by a current sensing transformer with the phase currents passing through the common aperture in parallel. The magnetic field induced in the transformer core is then the vector sum of the three individual phase currents and the voltage induced in the secondary winding placed on the transformer provides a signal representing the vector sum of the currents, the ground fault current.\n\nThe electrical characteristics of ground faults in solidly grounded WYE systems allow for simple detection of ground currents by monitoring the phase and neutral currents for a simple unbalance in those currents. The principle is that the current going to the load on the normal phase and neutral conductors should return via those same conductors. Any missing current is deemed a fault to ground on the load side of the detector and, when that unbalance exceeds a set threshold, a ground fault is determined. The basic ways of measuring this unbalance for solidly grounded four-wire systems use one ground sensor surrounding the phase and neutral conductors, four individual current transformers connected in a WYE configuration, or four voltage sources connected in a delta configuration.
797208
Not the easiest thing to explain via email but the best way to start is to understand clearly the function of the symbols shown in diagram. Once you understand what each item does find a starting point - usually the power supply and walk through it. ANother way is to get the corresponding termination diagram. I find them much easier to understand.