Originally Posted by brian john You are way off base on this, the “WYE” side is grounded at the service, how can a load the transformer take a solidly grounded wye system and un-ground it? I’m not off base here, my responses were in regard to your direction to Amelco to not bring a neutral to the transformer or to connect anything to it: This caused me to subsequently post this comment, ” You can not necessarily by NEC operate both systems ungrounded, what does the Earth care if there is a giant transformer sitting on it? Originally Posted by brian john Here read this, this is regarding a wye wye http: Originally Posted by brian john Here read this, this is regarding a wye wye How do you deal with the fact that the installation your are discussing is an NEC violation.
A Field Guide to the North American Utility Pole
Your drawing showing the hook-ups is a little small and I little hard to read, but looks correct. What you have here is a Delta to Wye connected transformer. The primary side is connected in a delta configuration. The secondary is connected in a Wye configuration.
Feb 23, · I understood Amelco was intending to make a 3-phase transformer connection where Amelco wanted to step Y/ volts up to volts Delta. If that is a correct understanding, then the Wye side of the transformer must be solidly grounded, otherwise the voltage will float.
Input Phase Angle and number of transformers needed. For High-Delta, type of transformer. It is used in business where you’re not running a lot of heavy motorized equipment. If you view the waveform on an oscilloscope, you will see a single sine wave single phase when measuring between Line 1 and Line 2 below at VAC RMS. You need three separate transformers, one for each phase.
The primary on each is fed with a single phase and produces an output of a single phase on Y or Delta VAC. Depending on whether the circuit is Wye or Delta, you can have multiple voltages. Each phase-pair carries the full voltage. On Wye with Neutral, the voltage between the phase and Neutral will be slightly less than three-fifths of it’s one-third of the square root of 3, for electronics geeks the voltage between each phase leg. On Delta, you only have each phase available with no Neutral.
If we hook up an oscilloscope to each of the line terminals, we see the following waveform, three independent power paths, degrees phase shifted which when applied to a three phase motor, provide a rotating vortex magnetic field which makes 3 phase motors self-starting without the requirement of a start capacitor, start winding or other method of kludging in a phase shifted winding to provide the rotational force to start the motor spinning. Wye and Delta typically have one Pole Pig per phase three transformers.
Transformer secondary electrical schematics below to show how each transformer set is hooked up to derive the connection scheme. You can hook a single phase motor up on L1-L2, L2-L3 or L3-L1 for single phase current balance necessary on loading between phases or apply L1-L2-L3 to the proper therminals of a three phase motor.
The Basics of Delta-Wye Transformers
When it comes to making proper transformer connections, more industry professionals choose the delta-wye connection than any other 3-phase transformer connection in power distribution. Why is it so popular? You can use the secondary to provide a neutral point for supplying line-to-neutral C. Sankaran Dec 01, The electrical configuration of the delta-wye transformer makes it the most popular transformer connection in the world. You can use the secondary to provide a neutral point for supplying line-to-neutral power to serve single-phase loads and ground the neutral point for safety reasons.
3E Technology, Inc. Part Number & Description List: (Partial List, More than kb) Please note that some of the lists are quite long! Please select company by clicking on one of the characters.
Be sure to ask your students to describe how they arrived at the answers to this question. There is more than one place to start in determining the solution here, and more than one way to calculate some of the figures. No matter how your students may have approached this question, though, they should all obtain the same answers. Question 8 What resistor values would we have to choose in a Delta configuration to behave exactly the same as this Y-connected resistor network?
There exist long, complicated equations for converting between Y and Delta resistor networks, but there is a much simpler solution to this problem than that! Challenge your students to solve this problem without resorting to the use of one of those long conversion formulae. Question 9 What will happen in each of these systems to the phase voltages of the load, if one of the source phases fails open? Hide answer In the Y-Y system, with no neutral wire, one of the load phases will completely lose power, while the voltages of the other two load phases will be reduced to In the Delta-Y system, none of the phase voltages will be affected by the failure of the source phase winding.
Ask your students what these results indicate about the reliability of Y versus Delta source configurations. Also, be sure to ask what does change in the Delta-Y system as a result of the failure. Certainly, something must be different from before, with one winding completely failed open! Question 10 A common three-phase source connection scheme is the Delta high-leg or Four-wire Delta, where each phase coil outputs volts:
Star/Delta motor connection 380V/220V
That would be the equivalent of applying volt to v windings so clearly the motor would fail. Of Couse all 6 motor windings must be accessible. As stated above, you can take a v, 3 phase star connected motor and run it as a v , three phase delta connected motor. Going back to basics it is the current driven by the voltage that creates the flux.
Wye/Delta or Y/ Connection Delta/Wye or /Y Connection Open-Delta or V-V TRANSFORMER:TRANSFORMER: THREE PHASE particular instant. It will be seen that at any instant, the amount of ‘up’ flux in any leg is equal to the sum of ‘down’ fluxes in the other two legs.
If needed refer to the information below. Pay no attention to the very slight readings on the ohm meter as that is continuity thru the windings. Changing the voltage to a motor with unmarked leads now wired;Dual voltage Wye connected Example motor is wired volt connected. Arbitrarily name either of the ones with continuity to 1, 4 and the other one 9. I have lost track of the leads of a nine lead three phase motor. How can I re-identify these leads? For the purpose of this test, a lantern battery of six or nine volts works best.
Battery and voltmeter leads should be properly identified. Alligator clips should be used on both. The motor must be completely assembled. Test the nine leads for continuity with the ohmmeter to determine whether the motor is star wye or delta connected. The delta connected motor will possess three sets of three leads with continuity between them. On the other hand, the star connected motor will have only one set of three leads with continuity between them, and three sets of two leads with continuity.
Following are specific steps to take when identifying leads of both a star connected and a delta connected motor.
Uses[ edit ] Synchro systems were first used in the control system of the Panama Canal in the early s to transmit lock gate and valve stem positions, and water levels, to the control desks. Early systems just moved indicator dials, but with the advent of the amplidyne , as well as motor-driven high-powered hydraulic servos, the fire control system could directly control the positions of heavy guns.
Digital devices such as the rotary encoder have replaced synchros in most other applications.
Most utility companies will not hook up 3 phase delta on the customer side anymore because the the “high” or “wild” leg, which as shown in the diagram runs a good deal higher than volts to neutral.
Monday Wye vs Delta Motor Connections In general, three phase motor windings are connected either in a wye or a delta. I say “in general” because some motors are not pre-connected either way. We’ll discuss that in a minute. The primary reason for connecting in wye or delta is basically for manufacturing convenience. So, all we can do is connect the motor for the correct voltage.
Most motor nameplates have connection data for low or high voltage. If not, there are many charts and publications out there that will show you those connections. One great source is a small handbook put out by our trade association, EASA, that is literally pocket sized and contains a wealth of information. It is called the “Electrical Engineering Pocket Handbook. These should be available from your local motor rewind shop.
Another common source is George Hart’s “Ugly’s” book.
Three Phase Transformers
There is a back cover protecting the Energy monitoring Board EMB to prevent contact with circuit board components and potentially harmful AC voltage wiring. If the conditions subsequently clear and re-occur or if additional warnings occur, the common alarm output will come back on. This operating sequence is basically a set of machine states that happen in a pre-determined order.
Machine states can be set to zero if not needed, or adjusted to fit the application. Stopped Mode Generator has come to a complete stop.
The installation of a /V delta/wye drive isolation transformer with the center of the wye grounded ended the drive problems but, as far as I know, the plant power network is still out there floating in the breeze (or worse!).
But voltage transformers can also be constructed for connection to not only one single phase, but for two-phases, three-phases, six-phases and even elaborate combinations up to phases for some DC rectification transformers. If we take three single-phase transformers and connect their primary windings to each other and their secondary windings to each other in a fixed configuration, we can use the transformers on a three-phase supply. Three-phase supplies have many electrical advantages over single-phase power and when considering three-phase transformers we have to deal with three alternating voltages and currents differing in phase-time by degrees as shown below.
Three Phase Voltages and Currents Where: VL is the line-to-line voltage, and VP is the phase-to-neutral voltage. A transformer can not act as a phase changing device and change single-phase into three-phase or three-phase into single phase. To make the transformer connections compatible with three-phase supplies we need to connect them together in a particular way to form a Three Phase Transformer Configuration. The advantages of building a single three phase transformer is that for the same kVA rating it will be smaller, cheaper and lighter than three individual single phase transformers connected together because the copper and iron core are used more effectively.
The methods of connecting the primary and secondary windings are the same, whether using just one Three Phase Transformer or three separate Single Phase Transformers. Consider the circuit below: Three Phase Transformer Connections The primary and secondary windings of a transformer can be connected in different configuration as shown to meet practically any requirement. In the case of three phase transformer windings, three forms of connection are possible: The combinations of the three windings may be with the primary delta-connected and the secondary star-connected, or star-delta, star-star or delta-delta, depending on the transformers use.
When transformers are used to provide three or more phases they are generally referred to as a Polyphase Transformer.
Delta and Wye 3-Phase Circuits
Can you just rewire them like changing voltages or ? What happens if you put a Y motor on a Delta source or vice-versa? Don’t jack about three phase, so
The basic theory underlying the operation of delta- and wye-connected distribution systems is also presented, and the differences between the two systems are discussed. The program also explains how to differentiate between KV systems and KV systems.
This is not enough when it comes to driving a motor that produces heavy torque or driving an air conditioner. To overcome the need for heavy power, the three-phase system of power was introduced. In three-phase, peak power appears three times for each half cycle of a complete waveform. As in single phase, we need a transformer to step-up or step-down 3-phase voltage according to our requirement.
These two sets of primary and secondary windings can be connected in either star or delta configurations. Both these configurations have their own plus points. Delta configuration provides full load even if one winding is open failed.
Three Phase Transformers
The eddy current loss is a complex function of the square of supply frequency and inverse square of the material thickness. Magnetostriction related transformer hum Magnetic flux in a ferromagnetic material, such as the core, causes it to physically expand and contract slightly with each cycle of the magnetic field, an effect known as magnetostriction , the frictional energy of which produces an audible noise known as mains hum or transformer hum.
Stray losses Leakage inductance is by itself largely lossless, since energy supplied to its magnetic fields is returned to the supply with the next half-cycle.
The majority of their offerings are 3 rail AC locomotives that need track with center studs. These locomotives have skis underneath them in between the drivers. The rails are ground/neutral (both same polarity) and the center studs are hot. The transformer hook .
If all they need is line voltage, use a Delta secondary. Harmonics are extra cycles added into the cycles already present and can damage sensitive electronics. You can hear harmonics as noise produced by transformers and such, wasted energy. The bonding jumper helps neutralize this some more. A neutral is unnecessary on a straight up Delta, so there is no need for it here. The transformers still do their job as they should without it hooked up, and it saves materials and time.
There is another thing that needs mentioning.
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I thought of that. Just hate to reduce the efficiency if not necessary. Originally Posted by petersonra the welder is no big deal either. And that is a suggestion I hadn’t thought of. Still, considering that all three pieces of equipment he has added are 2-pole, V, I can only assume that any plans he may have for the future would continue along that same schedule.
Star/Delta motor connection V/V Thursday, January 22, If the motor is designed to run in star a V 3-phase power supply, then it cannot be connected in delta on the ‘same’ supply.
The open delta three phase service By Paul Thurst, on February 27th, 5 comments Several months ago, I drove up to an FM transmitter site, looked up at the utility pole and saw this: Three Phase open delta transformer bank Three phase open delta is a bad hombre. Most, if not all, transmitter manufactures will void the warranty of any transmitter connected to a service like this. What is perplexing is it appears that all three phases are available on the primary side, why would this be necessary?
Perhaps it was not always so at this location. Regardless, this was the source of power for 20 KW FM transmitters since until we moved it to a new building last month. According to a GE publication on transformers, open delta 3 phase power is undesirable because: Although this connection delivers three-phase currents which are approximately symmetrical to a three-phase symetrical load, the currents flowing in the high voltage circuit are not equal nor are they degrees apart. The system is grossly unbalanced, both electrostatically and electromagnetically.