Industrial Maintenance Technician Certification Exam
(2026-2027) : 200 Practice Questions with Correct
Answers & Critical Diagnoses – Complete Study
Guide for Millwright, EET, CMRT, and CMMS Exam
Prep (Electrical, PLC, Hydraulics, Pneumatics,
Mechanical Drives, Safety, LOTO, NFPA 70E, Welding,
Rigging)
Introduction:
Master the Industrial Maintenance Technician Exam – 200 realistic practice
questions covering PLCs, motor controls, hydraulics, pneumatics, mechanical
drives, welding, safety, and electrical theory. Each answer is clearly marked
in bold for quick review, with bold italic for high-stakes troubleshooting situations.
Perfect for MILLWRIGHT, EET, CMRT, or CMMS certification prep. Boost your pass
rate with exam-style questions used by industrial training programs.
Question Set (1–200)
Electrical & Motor Controls (1–30)
1. A three-phase induction motor draws high current and hums but does not turn. Most
likely cause:
o Open in one phase
o Low voltage on all three phases
o Burned out start capacitor
,o Oversized overload relay
o
2. The device used to protect a motor from overheating due to prolonged overload is a(n):
o OL relay (overload relay)
o Fuse
o Circuit breaker
o Contactor
3. A DMM measures 0 ohms across a closed contactor. This indicates:
o Open coil
o Contacts are welded closed
o Shorted coil
o Normal operation
4. The minimum wire bending space for a 250 kcmil copper conductor in a panel is found
in:
o Ohm’s law
o NEC Table 312.6(B)
o UL 508A
o NFPA 70E
5. What is the synchronous speed of a 4-pole, 60 Hz induction motor?
o 900 RPM
o 1800 RPM
o 1200 RPM
o 3600 RPM
6. A VFD trips on “DC bus overvoltage.” Likely cause:
o Motor short circuit
o Regenerative load / deceleration too fast
o Input line under voltage
o IGBT failure
7. Which device converts AC to DC in a VFD?
o IGBT
o Rectifier
o Inverter
o DC link choke
8. A motor overload relay that uses a heater element and bimetal strip is:
o Solid-state
o Thermal overload
o Magnetic only
, o Electronic
9. Interlocking two contactors prevents:
o Overcurrent
o Simultaneous closure (short circuit)
o Voltage drop
o Arc flash
10. The most common failure in a motor starter is:
o Coil burnout
o Pitted / welded contacts
o Chattering
o Enclosure corrosion
11. A megger measures:
o Voltage
o Current
o Insulation resistance
o Continuity
12. Minimum insulation resistance for a 480V motor (megger reading):
o 0.5 MΩ
o *1 MΩ + (rule of thumb 1 MΩ per kV + 1 MΩ)*
o 5 MΩ
o 100 kΩ
13. A reversing motor starter requires:
o One contactor
o Two mechanically/electrically interlocked contactors
o One VFD only
o Three overload relays
14. What NEMA classification for a motor starter means “severe dust and lint”?
o Type 1
o Type 4
o Type 12
o Type 7
15. Across-the-line starting produces:
o Reduced voltage
o High inrush current (600% FLA)
o Soft stop
o Low torque
16. Which sensor detects magnetic fields without contact?
(2026-2027) : 200 Practice Questions with Correct
Answers & Critical Diagnoses – Complete Study
Guide for Millwright, EET, CMRT, and CMMS Exam
Prep (Electrical, PLC, Hydraulics, Pneumatics,
Mechanical Drives, Safety, LOTO, NFPA 70E, Welding,
Rigging)
Introduction:
Master the Industrial Maintenance Technician Exam – 200 realistic practice
questions covering PLCs, motor controls, hydraulics, pneumatics, mechanical
drives, welding, safety, and electrical theory. Each answer is clearly marked
in bold for quick review, with bold italic for high-stakes troubleshooting situations.
Perfect for MILLWRIGHT, EET, CMRT, or CMMS certification prep. Boost your pass
rate with exam-style questions used by industrial training programs.
Question Set (1–200)
Electrical & Motor Controls (1–30)
1. A three-phase induction motor draws high current and hums but does not turn. Most
likely cause:
o Open in one phase
o Low voltage on all three phases
o Burned out start capacitor
,o Oversized overload relay
o
2. The device used to protect a motor from overheating due to prolonged overload is a(n):
o OL relay (overload relay)
o Fuse
o Circuit breaker
o Contactor
3. A DMM measures 0 ohms across a closed contactor. This indicates:
o Open coil
o Contacts are welded closed
o Shorted coil
o Normal operation
4. The minimum wire bending space for a 250 kcmil copper conductor in a panel is found
in:
o Ohm’s law
o NEC Table 312.6(B)
o UL 508A
o NFPA 70E
5. What is the synchronous speed of a 4-pole, 60 Hz induction motor?
o 900 RPM
o 1800 RPM
o 1200 RPM
o 3600 RPM
6. A VFD trips on “DC bus overvoltage.” Likely cause:
o Motor short circuit
o Regenerative load / deceleration too fast
o Input line under voltage
o IGBT failure
7. Which device converts AC to DC in a VFD?
o IGBT
o Rectifier
o Inverter
o DC link choke
8. A motor overload relay that uses a heater element and bimetal strip is:
o Solid-state
o Thermal overload
o Magnetic only
, o Electronic
9. Interlocking two contactors prevents:
o Overcurrent
o Simultaneous closure (short circuit)
o Voltage drop
o Arc flash
10. The most common failure in a motor starter is:
o Coil burnout
o Pitted / welded contacts
o Chattering
o Enclosure corrosion
11. A megger measures:
o Voltage
o Current
o Insulation resistance
o Continuity
12. Minimum insulation resistance for a 480V motor (megger reading):
o 0.5 MΩ
o *1 MΩ + (rule of thumb 1 MΩ per kV + 1 MΩ)*
o 5 MΩ
o 100 kΩ
13. A reversing motor starter requires:
o One contactor
o Two mechanically/electrically interlocked contactors
o One VFD only
o Three overload relays
14. What NEMA classification for a motor starter means “severe dust and lint”?
o Type 1
o Type 4
o Type 12
o Type 7
15. Across-the-line starting produces:
o Reduced voltage
o High inrush current (600% FLA)
o Soft stop
o Low torque
16. Which sensor detects magnetic fields without contact?
