Control devices

What are contactors usually rated to switch current to?

• Computers and servers

• Motors, lights and heaters

• Televisions and radios

• Refrigerators and air conditioners

Which of the following is true about NEMA designed contactors?

• They are not serviceable

• They are prevalent in non-US markets

• They are only UL listed and rated

• They are inherently touch safe

Which of the following is true about IEC designed contactors?

• They are serviceable in lower HP ratings

• They are prevalent in enclosed starters and motor control centers (MCC)

• They are comparatively smaller than NEMA contactors

• They have six application choices from fractional to 400HP (480V)

What does a Combination starter consist of?

• A MSP and a relay

• A MSP and a contactor

• A contactor and a relay

• A relay and a circuit breaker

What is the primary function of a soft starter in a motor?

• To vary the speed of the motor

• To provide a reduced voltage motor start

• To increase the inrush current

• To provide branch circuit protection

In which scenario might a soft starter be used for a reduced torque motor start?

• In a high-speed train where a sudden start could cause discomfort to passengers

• In a computer fan where a sudden start could cause a system crash

• In a wind turbine where a sudden start could cause structural damage

• In a bottling conveyor where a sudden start or stop could damage the bottles

When are Variable Frequency Drives (VFDs) typically used?

• When the speed of the motor needs to be constant

• When the speed of the motor needs to be varied

• When the motor needs to be stopped

• When the motor needs to be started

What is a benefit of reducing the speed of the motor using a VFD?

• It increases the motor’s energy consumption

• It has no effect on the motor’s energy consumption

• It causes the motor to overheat

• It reduces the motor’s energy consumption

What is an example application of a VFD?

• A light bulb with integrated brightness control

• A computer with integrated power control

• A water pump with integrated flow control

• A car with integrated speed control

What type of start do hybrid motor starters use?

• Solid-state start that is bypassed by relay for run

• Mechanical start that is bypassed by relay for stop

• Solid-state start that is bypassed by relay for stop

• Mechanical start that is bypassed by relay for run