Motor Drive Protection Circuits

What type of relay can provide thermal protection for a motor?

• Timer relay
• Delay relay
• Thermal relay
• Pushbutton switch

What does an on-delay relay do when it is energised?

• Switches immediately
• Delays switching
• Switches off
• Remains unchanged

Which component is used for soft-starting a motor?

• Pushbutton switch
• Thermal relay
• Delay relay
• Fuse

What does the thermal protection relay connect to in the motor?

• Contactor
• Delay relay
• Fuse
• Thermistor

What is the function of a star contactor in a motor control system?

• To switch the motor off
• To provide forward operation
• To provide reverse operation
• To enable soft-starting

What happens to the switches of an off-delay relay when it is de-energised?

• Switches immediately
• Delays switching
• Remains unchanged
• Switches off

In the control circuit, what arrangement prevents both forward and reverse contactors from being energised at the same time?

• Latch
• Interlock
• Series
• Parallel

Which device is used to protect a motor from overload conditions?

• Fuse

• Thermal relay

• Contactor

• Pushbutton switch