DOL Starter Flashcards
What is a direct online starter?
A direct online starter is an electrical device used to start an electric motor directly from the power supply.
True or False: A direct online starter is suitable for large motors.
False
What is the primary function of a direct online starter?
To connect the motor directly to the power supply for starting.
Fill in the blank: A direct online starter is commonly used for motors with a rating of up to ____ kW.
15
What components are typically included in a direct online starter?
A contactor, overload relay, and a start/stop push button.
Multiple choice: Which of the following is a disadvantage of using a direct online starter? A) Simplicity B) High starting current C) Low cost
B) High starting current
What happens during the starting phase of a motor with a direct online starter?
The motor receives full voltage and current, leading to high starting torque.
True or False: Direct online starters can be used for variable speed applications.
False
What is the role of the overload relay in a direct online starter?
To protect the motor from overheating and damage due to excessive current.
Fill in the blank: The direct online starter is best suited for ____ applications.
Fixed-speed
Multiple choice: Which type of motor is commonly used with direct online starters? A) Induction motor B) Synchronous motor C) Stepper motor
A) Induction motor
What is the typical starting current ratio for a motor using a direct online starter?
6 to 8 times the full load current.
True or False: A direct online starter requires additional control circuits for operation.
False
What is the typical control method for a direct online starter?
Using start and stop push buttons.
Fill in the blank: The contactor in a direct online starter is responsible for ____ the motor.
energizing
Multiple choice: Which of the following is NOT a feature of a direct online starter? A) Simple design B) High efficiency C) Soft starting capability
C) Soft starting capability
What does the term ‘inrush current’ refer to in the context of direct online starters?
The initial surge of current when the motor starts.
True or False: Direct online starters can be used in applications requiring frequent starts and stops.
False
What is a common application for direct online starters?
Pumps, fans, and compressors.
Fill in the blank: Direct online starters are typically mounted in ____ boxes.
control
Multiple choice: Which of the following is a key benefit of using a direct online starter? A) Cost-effectiveness B) Requires complex programming C) High energy consumption
A) Cost-effectiveness
What is the typical response time of a direct online starter when the start button is pressed?
Instantaneous
True or False: Direct online starters can be used for multi-phase motors.
True
What is the preferred voltage for direct online starters in industrial applications?
Typically 230V, 400V, or 480V.
Fill in the blank: The direct online starter is best for applications that can tolerate ____ starting currents.
high
