NEIEP 400 Final Exam Review - Complete Study
Guide with Actual Exam Questions, Verified
Correct Answers & Detailed Rationales | Latest
Test Updated 2026/2027 | Graded A+
Question 1
What material should be used for seating brushes?
Answer: Sandpaper ✔✔
Rationale: Sandpaper (specifically fine grit, NOT emery cloth) is used to seat brushes
to the commutator contour. Emery cloth contains conductive particles that can cause
short circuits between commutator segments.
Question 2
Readings on the meter appear to be inaccurate, what should you do?
Answer: Check the meter's battery and calibration, and verify connections ✔✔
Rationale: Inaccurate meter readings can be caused by low battery, improper range
selection, poor connections, or the need for calibration. Always verify these factors
before assuming component failure.
Question 3
A machine that converts mechanical energy into electrical energy:
Answer: Generator ✔✔
Rationale: A generator converts mechanical energy into electrical energy through
electromagnetic induction. Motors convert electrical energy into mechanical energy.
Question 4
What is the purpose of interpoles in a motor?
Answer: Helps prevent neutral planes from shifting ✔✔
pg. 1
,Rationale: Interpoles (commutating poles) are small auxiliary poles placed between
the main poles. They generate a voltage in the armature coils undergoing commutation
to counteract reactance voltage and prevent neutral plane shifting.
Question 5
In the basic loop circuit generator armature supplies DC power to what DC elevator
hoist motor component?
Answer: Motor Armature ✔✔
Rationale: The generator armature produces DC power that is supplied to the hoist
motor armature through the main power circuit. This is the primary power delivery path
in Ward Leonard elevator systems.
Question 6
If you have leakage resistance to ground, what will you use to test?
Answer: Megger (megohmmeter) ✔✔
Rationale: A megger applies a high voltage (500V-1000V) to measure insulation
resistance to ground. It detects leakage through insulation breakdown, which a standard
ohmmeter cannot detect.
Question 7
What kind of device would you use to measure current without disconnecting wiring?
Answer: Clamp-on ammeter ✔✔
Rationale: A clamp-on ammeter (clamp meter) measures current by sensing the
magnetic field around a conductor without breaking the circuit. This allows safe, non-
invasive current measurement.
Question 8
What is the synchronous speed of 3 phase, 60 Hz, 6 pole motor?
Answer: 1200 RPM ✔✔
Rationale: Synchronous speed formula: RPM = (120 × Frequency) ÷ Number of Poles.
RPM = (120 × 60) ÷ 6 = 7200 ÷ 6 = 1200 RPM.
pg. 2
, Question 9
Before attempting to measure resistance in an unknown resistor in a circuit, what must
be done?
Answer: Isolate from one side ✔✔
Rationale: To measure resistance, at least one side of the component must be
disconnected from the circuit to prevent parallel path readings. This ensures the
measurement reflects only the component being tested.
Question 10
What is the method used to resolve residual magnetism to an exciter?
Answer: Flashing the field ✔✔
Rationale: Flashing the field applies a DC voltage briefly to the field windings to
restore residual magnetism in the generator's field poles. This is necessary when a
generator loses its residual magnetism and fails to self-excite.
Question 11
What is the inherent current limiter present for a rotating motor armature called?
Answer: CEMF (Counter Electromotive Force) ✔✔
Rationale: CEMF is the voltage generated in the armature that opposes the applied
voltage. It increases with speed and limits armature current. I = (V - CEMF) / R.
Question 12
What is the function of a field protective relay (FPR) in an elevator motor circuit?
Answer: Protects against loss of shunt field current, which would cause motor
overspeed ✔✔
Rationale: The field protective relay (FPR) is connected in series with the shunt field.
If field current drops below a safe level (open circuit), the FPR opens the armature
circuit, preventing motor overspeed that would occur from loss of field.
Question 13
pg. 3
Guide with Actual Exam Questions, Verified
Correct Answers & Detailed Rationales | Latest
Test Updated 2026/2027 | Graded A+
Question 1
What material should be used for seating brushes?
Answer: Sandpaper ✔✔
Rationale: Sandpaper (specifically fine grit, NOT emery cloth) is used to seat brushes
to the commutator contour. Emery cloth contains conductive particles that can cause
short circuits between commutator segments.
Question 2
Readings on the meter appear to be inaccurate, what should you do?
Answer: Check the meter's battery and calibration, and verify connections ✔✔
Rationale: Inaccurate meter readings can be caused by low battery, improper range
selection, poor connections, or the need for calibration. Always verify these factors
before assuming component failure.
Question 3
A machine that converts mechanical energy into electrical energy:
Answer: Generator ✔✔
Rationale: A generator converts mechanical energy into electrical energy through
electromagnetic induction. Motors convert electrical energy into mechanical energy.
Question 4
What is the purpose of interpoles in a motor?
Answer: Helps prevent neutral planes from shifting ✔✔
pg. 1
,Rationale: Interpoles (commutating poles) are small auxiliary poles placed between
the main poles. They generate a voltage in the armature coils undergoing commutation
to counteract reactance voltage and prevent neutral plane shifting.
Question 5
In the basic loop circuit generator armature supplies DC power to what DC elevator
hoist motor component?
Answer: Motor Armature ✔✔
Rationale: The generator armature produces DC power that is supplied to the hoist
motor armature through the main power circuit. This is the primary power delivery path
in Ward Leonard elevator systems.
Question 6
If you have leakage resistance to ground, what will you use to test?
Answer: Megger (megohmmeter) ✔✔
Rationale: A megger applies a high voltage (500V-1000V) to measure insulation
resistance to ground. It detects leakage through insulation breakdown, which a standard
ohmmeter cannot detect.
Question 7
What kind of device would you use to measure current without disconnecting wiring?
Answer: Clamp-on ammeter ✔✔
Rationale: A clamp-on ammeter (clamp meter) measures current by sensing the
magnetic field around a conductor without breaking the circuit. This allows safe, non-
invasive current measurement.
Question 8
What is the synchronous speed of 3 phase, 60 Hz, 6 pole motor?
Answer: 1200 RPM ✔✔
Rationale: Synchronous speed formula: RPM = (120 × Frequency) ÷ Number of Poles.
RPM = (120 × 60) ÷ 6 = 7200 ÷ 6 = 1200 RPM.
pg. 2
, Question 9
Before attempting to measure resistance in an unknown resistor in a circuit, what must
be done?
Answer: Isolate from one side ✔✔
Rationale: To measure resistance, at least one side of the component must be
disconnected from the circuit to prevent parallel path readings. This ensures the
measurement reflects only the component being tested.
Question 10
What is the method used to resolve residual magnetism to an exciter?
Answer: Flashing the field ✔✔
Rationale: Flashing the field applies a DC voltage briefly to the field windings to
restore residual magnetism in the generator's field poles. This is necessary when a
generator loses its residual magnetism and fails to self-excite.
Question 11
What is the inherent current limiter present for a rotating motor armature called?
Answer: CEMF (Counter Electromotive Force) ✔✔
Rationale: CEMF is the voltage generated in the armature that opposes the applied
voltage. It increases with speed and limits armature current. I = (V - CEMF) / R.
Question 12
What is the function of a field protective relay (FPR) in an elevator motor circuit?
Answer: Protects against loss of shunt field current, which would cause motor
overspeed ✔✔
Rationale: The field protective relay (FPR) is connected in series with the shunt field.
If field current drops below a safe level (open circuit), the FPR opens the armature
circuit, preventing motor overspeed that would occur from loss of field.
Question 13
pg. 3
