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Explain the necessity for the use of a starter with a dc motor?
Wiki User
∙ 14y ago
In its simplest form, the starter of a dc motor is a variable resistance in series with the armature circuit of dc motor to reduce the high starting current so that the armature winding does not get overheated and burnt while the motor isgetting started. As the rotating armature of dc motor picks up speed, the starter resistance is gradually reduced so that the motor is able to attain its full speed when the starter is not expected to offer any additional resistance in series with the armature winding of the dc motor. At full speed the motor starts running normally, of course, without the help of starter. In other words, the starter offers resistance to armature current during starting of dc motor only. Under normal working condition of dc motor , the starter is electrically out of armature circuit of the motor. The starter protects the armature of dc motor from getting damaged. The electromotive force (emf) induced in the armature winding during starting builds up from zero value to max value to restrict the armature current within the permissible value at full speed. As the speed of armature/motor build up, armature induced emf also starts building thus reducing the role resistance offered by the starter, hence requiring it to gradually reduce as the motor picks up full speed.
Wiki User
∙ 14y ago
Wiki User
∙ 12y agono need to think more about starters
they are just switces to control the motor on off
as concerned with motors these switches are called starters
there are three kinds of starters depending on the load
DOL direct on line
stardelta
soft
these starters have thick contacts for better with-standing during start and running operations of a motor. well now a days these are provided with overload relays for safe operations
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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.
Can you use washing machine motor as a generator?
no
What do scientist use to explain the expanding universe?
Dark energy.
What size generator do you need for a 250 hp 480V motor that had a across the line starter?
The first thing that is required is the amperage of the motor. I = HP x 746/1.73 x E x %eff x pf. This comes to about 277 amps. The second formula to use to find KVA is KVA = I x E x 1.73/1000 = 277 x 480 x 1.73/1000 = 230. The minimum size generator will be 230 KVA.
Why you use starter in DC motor?
to control on of operations
Can a voltmeter be used to measure voltage in and out of a starter motor?
Voltage flow into a starter motor, never out of it. Use the voltmeter to measure the voltage at the starter motor before starting to crank and then whilst it is cranking. (Before cranking, the voltage appears across the starter motor relay only.)
Why using on motor star delta starter?
because at the starting the induction motor drawn a heavy current thats why we use starter to increase the starting resistance of the induction motor!
Can DOL starter use for 50kw motor?
The answer is yes. I had seen 110kW pump start on DOL starter
How much KW range can be use star-delta starter?
The use of a star delta starter is for motor control only and not resistive heating loads. This type of starter is used to dampen the inrush current by using a lower voltage to start the motor.
How do you start a motor without a starter?
By the use of auto transformer and bridge rectifier we can start dc motor.
Can you use any starter for riding lawn mowers?
No you must have a starter from the same model and motor size. I think starters are very motor specific. Hope this helps.
Why you use DOL starter in starting of motor?
because of starting current of induction motor is very high and it damages the insulation of motor
Do you need a starter for a 3 phase 5 horse motor?
YES. USE THE NORMAL DIRECT-ON-LINE OR ACROSS-THE-LINE STARTER.
Can you use star delta starter and soft starter in to same motor?
Probably. More importantly, why would you want to? The Star/Delta starting method is used to minimize motor starting current, just like a soft starter. Use one or the other. There's no good reason to use both, it will just make things more complicated.
How do you put reverse on Yamaha r1 engine in a buggy?
FNR transmission or use a seperate sprocket and use a starter motor.
Want to know about two point starter?
In DC series motor, field and armature are in series. so we use only two points. They are line and armature. therefore we use two point starter.
