3 phase Definition and 126 Threads

For a building powered by a 3-phase feed, I need to estimate the amount of power available to 120v & 208v loads in the building. If the feed delivers 200A at 600v, is this 200A per phase (meaning 360 KVA total) or a third of that? TIA.

First post here. Found this place while looking for a solution to my problem. My background is Navy trained electronic tech. (FC to be precise) So an engineer I'm not, but I do fix the stuff. Anyway, at work, I have a 3 phase full wave rectifier with a capacitor ripple filter. Here's a...

PLZ HELP!3 phase supply keeps interchanging Hey friends, The power supplying company at my place keeps changing the phases on daily basis and this has caused a nuisance.. In my country the colour coding is "Red-Yellow-Blue" I have to change the Main supply wired to "Blue-Yellow-Red"...

Hi, I have a question. Suppose I have a motor that runs on 3 phase power. If I only wanted to find out the total amount of current that the motor draws, how would I go about doing that? Would I just use a clamp meter to get the amount of current going through each phase and then add them up...

I have a 125amp, 240v three phase circuit feeding a 30 kva UPS through a delta/wye transformer, leaving 208/120v three phase entering my panelboard. I plan to use 50 amp, 3 pole breakers, with a neutral and ground, making 5 wire three phase. My question is: When I bring the 5 wire, three...

Dear All, I’m facing some problem when I try to determine the total voltage drop (%) from the source to the load. Assume the condition as follow: 1. DB-A is serving 3 number of individual load (#1,#2 and #3) , each 100m away from DB-A, single phase, 5kw, pf=0.85, V=240V,by using...

The system with a balanced 3 phase load of 100kW at a 0.75 power factor, the system voltage is 12500V line to line, grounded wye. What size of capacitor can bring the power factor to 0.90 lagging, then what will be the real power?

I was given a 3 phase plasma cutter (no motor in machine only transformers)and my garage is only 1 phase. I have been doing a little research on converting 1 phase to 3 phase but it is just to expensive for my budget! I did come across an article that suggested that is can be done without a...

If the line current is 240V, 400Hz, 3 phase generator supplies a balanced 3 phase star connected load through a long 3 core cable. load phase is a 0.25 ohms resistor in series with a 130 (nano)H inductor. 3 core cable has negligable resistance and a line resistance of 0.1 ohms. How do hand...

https://www.physicsforums.com/attachment ... how do i measure the current flow threw the neutral wire if phase R is open circuited? the impedance per load is 3+7j

Can someone explain to me what a 3 phase IEC Contactor/starter is, how it works, and what its used for? Thanks

hi there, Looking for some info, on how i would find the current draw of a 2 Hp motor running at 208v 3 phase with a unity power factor and efficenty of 100%. I can't seem to put it together today and cannot get ahold of a TA, basically i need to size wires/fuses in a schematic for this...

Not a homework question, Just trying to get more information about it. Its hard to find a textbook or a site that explains this well. thanks

My dad and my uncle were wiring in a disconnect & panel in my dad's new shop the other day. It is a 600v 400A 3-phase connection. When they were wiring the 3 phase connection from the main disconnect to the panel, my uncle (whose an electrician) says to make all the conductors the same size...

I have an opportunity to purchase a surplus but new 3 ton central AC (heat pump) system for my home at an attractive price but it has a three phase compressor motor and I have single phase 220V service into my home. As I understand my options, I could replace the motor with a single phase unit...

Quick question on 3 phase before my final! Homework Statement In equations for 3 phase power there is an angle that is mentioned, but I don't know if this is the angle of the impedance or another angle. I am a little confused. The equations are below. Homework Equations...

I'm not sure where to post this one but i'll start with the mechanical guys first. There are two different motors that share identical ratings but different sizes physically. They are represented as though they perform the same work, share a common HP and KW rating and the mechanical device...

Six, 6.6kV ,3phase, alternators are connected to a common set of bus bars. Each has positive negative and zero sequence reactances of 0.90 ohm, 0.72 ohm, 0.30 ohms respectively . An Earth fault occurs on one bus bar . Determine the value of fault current if all alternator neutrals are solidly...

I have to answer a question on the advantages a 3 phase power supply has for an x-ray machine and the production of x-rays as compared to a single phase power supply. Could you please tell me if I have this correct and if there is anything else I could add? - 3 phase is about 150% more...

hi im a mechanical engineering student, and we are building an electric using a 3 phase 40 hp AC motor, which is oil cooled. The motor must be submerged in oil that is then circulated... the motor will produce up to 8000W-10000W of heat. does anyone know if it would be possible to use the...

I am trying to do a project on electrical engineering which involves design of electrical circuitry for a soot blower arrangement.i am having problems in designing a motor( 3phase induction motor). i know how to calculate the rotor parameters,losses, efficiency,etc. i am told that i have to find...

Hi! I'm working on a 3 phase induction motor. I need to measure the RMS values of three phase voltages, and single phase current which further feed power to the induction motor. I've implemented the true rms measurement (sum of squares method) algorithm for RMS value calculations and readings...

This is probably a simple question with a simple explanation... I understand that a 3 phase induction machine generates a rotating magnetic field in the stator which by Lenz’s law induces an electromagnetic force in the rotor which moves the rotor in the same direction as the stator magnetic...

Hi all, 3 phase power is measured using 2 and 3 wattmeter methods.Correct? can someone explain how these 2 work?I cudn get enuf info on it.

Hello to all. :smile: If I have a 240v 3 phase delta system, My phase to phase is 240V. there is no center tap on the phase for 120V. If I hook up a single phase 240V motor to 2 of the 3 phase delta legs, will the motor perform correctly? I didnt know if the 120 deg phase shift would keep...

i had a problem with a 3 phase motor last week that had me stumped, it would rapidly overheat even under no load, resistance readings of the windings cheked out ok as did short circuit tests, a report from the local rewind shop said that one of the BARS on the rotor was found to be the...