ELECTRO 3 - MOTOR TROUB

What is the biggest cause of motor failures according to statistics?

• bearing failure

• stator winding failure

• shaft bending

• coupling failure

Which of the following is the most likely cause of stator winding failure?

• overloading

• undervoltage

• bad installation

• underloading

Which of the following will NOT likely cause the bearing of the motor to fail?

• undervoltage

• excessive lubrication

• insufficient lubrication

• misalignment

How often do you have to re-grease sealed-for-life bearings of motors?

• they are not re-greased

• every 2000 hrs

• every 3 months

• every year

What is the main cause of shaft misalignment?

• soft foot

• hard foot

• club's foot

• athlete's foot

What is the major cause of stator winding overheating?

• excessive starts

• undervoltage

• misalignment

• soft foot

Which of the following causes shaft overload?

• damaged driven load bearing

• undervoltage

• excessive starts

• humidity

According to research, the life of the motor bearing doubles for every __________ in operating temperature

• 15 C drop

• 15 C rise

• 20 C drop

• 20 C rise

what is the industry standard for low voltage motors?

• Class F

• Class A

• Class D

• Class C

In Motor protection, IP means _______________

• Ingress protection

• internet protocol

• internal protection

• internal protocol