0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What device may be wired into the starting circuit of a motor to improve the starting torque?
I assume a 3 phase, AC induction motor. A star delta starter or a soft starter can be used. A soft starter is better compared to a star delta starter, but it is more expensive.
What is a soft starter?
A soft start is a starter that bring a motor from the starting point of a slow speed in to a multiple speed that can be programmed in the starter Imagine you have a big plant in your factory, the voltage will go down/up when the plant start/stop, cause the sharp start/stop The soft starter is controlling AC motor in soft start/stop to eliminate such problems. Reference: http://www.softstarter.org
Why are no starting components needed on three-phase motors?
Yes, by using a DOL Starter, which gives a controlled "soft-start" for the motor even though it is always connected in delta configuration.In this type of starting a 3-phase motor, full voltage is applied to the motor through relays and contactors. Its is the most common type of 3-phase motor starter used.DOL means Direct On-Line starter.
Why used star contactor half value then main and delta contactor in star delta starter?
This type of motor starting configuration is used to start large motors. The utility company's policy is to only let a certain three phase motor horsepower loads across the line starting. High horsepower loads draw high current which draws the line voltage down. This causes a small instantaneous brown out to which the utility company gets complaints about. To solve this problem, limit the horsepower load. Starting a delta motor in star configuration reduces the inrush current because the voltage applied to the motor is lower. This technology is rapidly becoming old due to the new type of motor controllers on the market. Replacing the star delta starters is soft start controllers. The inrush current can be controlled so as to not make any voltage drop on the line. These controllers are different from VFD's which are expensive for this type of application. The main function of the soft start is to get the motor on line without any line disturbances.
Which is better inverter or soft starter?
An inverter is just a device to invert one form of electrical power supplied to its input into another form of electrical power as its output. A soft starter may be included into an inverter design, its function is just to provide temporary power to the inverter until it gets started. After that the soft starter is disabled, usually by a diode feedback link.
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.
What device may be wired into the starting circuit of a motor to improve the starting torque?
I assume a 3 phase, AC induction motor. A star delta starter or a soft starter can be used. A soft starter is better compared to a star delta starter, but it is more expensive.
Soft starter for a dc motor?
It is an advanced power electronic device to start the motor with a very smooth starting curve. It is next generation starter compared to DOL or star Delta starter
What is a soft starter?
A soft start is a starter that bring a motor from the starting point of a slow speed in to a multiple speed that can be programmed in the starter Imagine you have a big plant in your factory, the voltage will go down/up when the plant start/stop, cause the sharp start/stop The soft starter is controlling AC motor in soft start/stop to eliminate such problems. Reference: http://www.softstarter.org
How a soft starter works?
nothing
How Soft starter work?
nothing
Is DOL starter is sufficient for 10HP 2880 RPM motor?
If the application is high starting torque, then go for star delta or soft starters. If not DOL will do.
What are the different types of starter?
DOL, Star Delta, Soft starter, VFD
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.
Soft starter tripping?
Most of the motors are usually controlled by the soft starters which usually trip frequently. One of the steps in find why the soft starter has tripped is looking at the motor circuit protector rating.
Why are no starting components needed on three-phase motors?
Yes, by using a DOL Starter, which gives a controlled "soft-start" for the motor even though it is always connected in delta configuration.In this type of starting a 3-phase motor, full voltage is applied to the motor through relays and contactors. Its is the most common type of 3-phase motor starter used.DOL means Direct On-Line starter.
How do you minimize the starting current of motor?
One method is to use a star delta starting configuration, two more are electronic starting. A variable speed drive and electronic soft start. These two are almost the same except the soft start doesn't have all the bells and whistles that the VFD has. The soft start usually comes with a bypass contactor. Once the motor is up to speed the bypass contactor cuts in and takes the load off of the soft start.
