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This answer has been temporarily closed to changesbecause so many askers have been repeatedly splitting-off variants of the question such as "Can you give me simple diagram for star-delta starter".
Please note: diagrams cannot be included in answers.
The answer given includes plenty of details for anyone to be able produce a simple diagram showing how a 3-phase motor can be wired in star and delta configurations.
AnswerTo be able to wire a 3-phase motor either in star or delta, all 6 ends of the three sets of coils, called "windings", have to be exposed with suitable connection terminals.
The windings are often labelled A1, A2, A3 and B1, B2, B3, where "1", "2" and "3" denote the separate phase windings and "A" and "B" denote the beginning and end of each winding.
Another way of describing it is to say that the separate windings can be labelled:
Winding 1: A1 <---> B1. Winding 2: A2<---> B2, Winding 3: A3 <---> B3.
In star configuration either all the A's or all the B's are connected together and the 3-phase supply (consisting of three separate "phase lines" labelled L1, L2, L3) is connected to the remaining three connectors. For example, if you connect B1 to B2 and B2 to B3 to form the center of the "star" then you must connect supply L1 to A1; supply L2 to A2 and supply L3 to A3.
In delta configuration, connect B1 to A2, B2 to A3, B3 to A1. (If you draw that out as a schematic diagram, it will be a triangle.) Then connect supply L1 to A1; supply L2 to A2 and supply L3 to A3. (Exactly the same as the supply lines were connected before, for the star configuration.)
The initial making of those connections in "star" - and subsequent changing into "delta" after the motor has built-up sufficient speed - would all normally be handled by a "star-delta motor starter" unit. A good tip: before you ever start hooking one up, study its schematic wiring diagram carefully to be sure you really understand which of its terminals connect to which motor terminals, and where to connect each line of the 3-phase service cable.
Note:
Some 3-phase motors use an alternative way of labelling the windings: 1A, 1B, 1C and 2A, 2B, 2C.
Electronic motor-control systems, which offer soft-starts in DELTA configuration, are now replacing the use of manual or semi-automatic star-delta starters.
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Why star delta timer required for motor?
The timer is used to give the motor time to reach its running speed at the star voltage. Once the timer times out the star contactor drops out and the delta contactor pulls in.
What is the advantage of a Star Delta Motor Starter?
The inrush current to the starting motor is lower due to the the motor coils being in series across the line creating a higher impeadence. When the starter connects to delta connection the motor is already turning and it does not have to go through the locked rotor phase. This system is being phased out now with the use of electronic soft starts and by-pass contactors.To start a motor direct on line (DOL) in delta requires approximately 6 to 8 times the full load current of the motor and delivers full torque. Delta places 415v across each of the windings on the motor. A Star-Delta starter starts the motor in Star which places 240v across each winding on the motor. This results in a lower starting current and also a lower starting torque.
How can you include phase failure relay in your star delta motor starter circuit?
The star delta motor starter circuit has to have a control voltage to energize the motor magnetic contractors. A phase failure relay monitors all three phases of the incoming supply lines. The phase failure relay also has auxiliary contacts on it. There are usually two sets of "C" form contacts. The control voltage for the starter circuit must be connected across the normally open (N.O.) contacts of one of these two sets. When the phase monitor is energized these N.O. contacts close supplying the control voltage to the circuitry of the star delta starters. If there is a phase interruption, phase reversal or phase loss, the phase failure relay will de-energize and the N.O. contacts will go back to their de-energized state. If the star delta motor starter is in use at the time, its control circuitry voltage will be lost and the delta motor magnetic contactor will open. The opening of this contactor will disconnect the motor from the failed three phase supply.
What are the names in the star wars delta squad?
boss, fixer, scorch, and sev.
What is the maximum neutral current for a three phase delta star system?
It is either a delta or a star, it can't be both. A delta system doesn't have a neutral so the question must be about a star system. A high neutral current happens for example when one line is disconnected, and the neutral current then equals the current in the other two lines, which is the same current as when two lines are disconnected leaving only one line.There might be ways of calculating how to make the neutral current larger by using unusual power factors, but the above is a useful working maximum that allows all four wires of a four-wire star system to be the same size.AnswerThe term, 'delta-star', refers to a three-phase transformer connection in which the primary windings are connected in delta while the secondary windings are connected in star (wye). This is the standard three-phase connection, in Europe, for distribution transformers. Single-phase loads are connected to the secondary between alternate lines and neutral, in order to try to and balance the resulting load and minimise any resulting neutral current. Obviously, however, without having any specifications supplied, it is quite impossible to answer this question.
How do you wire a three phase motor with two speed?
Star and delta connection
How can you wire a 6-pole isolator to disconnect a 6-wire star delta motor away from the mcc and near to the motor?
There is no need to place a 6 pole disconnect to isolate the motor in the field. The motor's leads at the motor's terminal box have to be wired for a delta connection. The star delta contactor in the MCC only has three wires on its output. Six wires do not have to be taken directly to the motor. The voltage is reduced at the start of the circuit when the starter in in the star configuration. From the star configuration it changes to the delta configuration. So as you can see only a three pole isolation switch is needed in the field to isolate the motor from its supply.
How can you wire a 3-pole isolator to disconnect a 6-wire star delta motor away from the mcc and near the motor?
You can't. You need a 6 pole isolator
Why use link in star contactor?
The link in the star contactor is used to form the star point of three of the motor leads. On most star wound motors the star point is inside the motor windings. On a motor that can be used for star delta starting it is a six wire motor. The star point winding depends on the contactor to tie the coil ends together externally in the control panel of the star delta starter.
What is Full load current for 40 HP star delta motor?
What is the continuous current of 10HP star delta motor
Should a star-delta motor be supplied wye or delta power?
A star-delta motor should be supplied star-delta.Wye is simply another name for star. Star-delta motors use a star or wye configuration to start, and a delta configuration to run. This reduces the voltage on the windings during the high current starting time.
What is a forward-reverse star delta?
A forward reverse star delta is a two in one motor starter where a motor first runs on star connection and then changed to delta connection after a time which has been set. The motor direction can be changed, whether forward or reverse
What will happen if induction motor is in star-star connected?
If a motor is connected in a star configuration it will operate at a slower speed. This is the working process that a star delta starter operates on. At first through the starter the motor starts in the star connection. When the motor gets up to its highest speed in that connection it times a timer out , the star starter drops out and the delta starter pulls in and then connects the motor in the delta connection. This allows more voltage to be applied to the motor and it then speeds up to its nameplate rated RPM.
What will cause a star delta panel to trip in delta?
On a star delta starter a motor overload or a motor going to ground and cause a short circuit will cause the overload protection to trip. These overloads have to be reset before the motor can be restarted.
Star delta motor what are the links across the terminal for?
That is the star point contactor that opens when it goes into the delta configuration.
How can a dlta connected motor be converted in star?
If the motor terminal has six terminals in the terminal box, then it can be connected either in delta or star. If there are only 3 terminal wires then the motor can not be connected in star.(it means that the motor is designed to be connected in delta only)
Star delta starter for 3 phase induction motor?
how will you start 3phase inuction motor using star delta stater
