South Carolina Automation
Maintenance Technician Certification
License Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A proximity sensor used in an automated manufacturing cell fails to
detect a metallic target. Which of the following is MOST likely to be
the cause?
A. The sensor’s operating voltage is too high
B. The sensor’s sensing face is misaligned
C. The cable shield is grounded correctly
D. The target material is non-ferrous
A misaligned sensing face is the most common cause of detection
failure because the sensor must be properly aimed at the target
within its rated sensing range.
2. A technician measures 128 V AC between two legs of a three-phase
supply and 208 V AC between each leg and neutral. What type of
three-phase system is this?
A. 480Y/277 V
B. 120/208Y V
C. 240 V Delta
, D. 600 V Delta
A 120/208Y system has 120 V phase-to-neutral and 208 V
phase-to-phase, fitting the measured values.
3. Which component in a programmable logic controller (PLC)
environment is responsible for converting real-world signals into logic
the CPU can process?
A. Power supply
B. CPU
C. Input/Output (I/O) module
D. Communication bus
I/O modules translate field device signals into digital data the PLC
CPU can interpret and act upon.
4. In motor control circuitry, what is the primary function of a contactor?
A. Provide overload protection
B. Control motor startup and shutdown
C. Measure motor current
D. Boost voltage to the motor
Contactors are electromechanical switches used to make or break
power to motors under control logic.
5. A temperature transmitter with a 4–20 mA output reads 5.2 mA with
the process at 50 % of span. What is the most likely cause?
A. Broken wiring
B. Power supply overload
C. Incorrect transmitter calibration
D. Faulty process connection
An output significantly below expected for mid-range typically
indicates calibration errors in the transmitter electronics.
6. In hydraulic systems, what does the term “dead-heading” refer to?
A. Leakage in return line
, B. Low fluid viscosity
C. Blocking actuator movement against pressure
D. Cavitation at pump inlet
Dead-heading describes a hydraulic actuator being prevented from
moving while fluid continues to be pumped, causing high pressure.
7. Which safety device will protect a three-phase motor from sustained
overcurrent?
A. Fuse
B. Pushbutton
C. Relay
D. Overload relay
Overload relays are designed to open the control circuit when motor
current remains high for a specified time to prevent overheating.
8. A ladder logic rung reads: XIC I:1/0 — OTE O:2/3. When input I:1/0 is
energized, what happens?
A. Output O:2/3 toggles
B. Timer starts running
C. Output O:2/3 energizes
D. Input is de-energized
An XIC (Examine If Closed) checks if the input is true, and with OTE
(Output Energize), if true the output is turned on.
9. A variable frequency drive (VFD) is installed and the motor hums but
doesn’t turn. What is the MOST likely issue?
A. VFD is underpowered
B. Motor is phased correctly
C. Control wiring is misconfigured
D. Drive ground fault
If the drive shows hum but no motion, control wiring or parameter
Maintenance Technician Certification
License Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A proximity sensor used in an automated manufacturing cell fails to
detect a metallic target. Which of the following is MOST likely to be
the cause?
A. The sensor’s operating voltage is too high
B. The sensor’s sensing face is misaligned
C. The cable shield is grounded correctly
D. The target material is non-ferrous
A misaligned sensing face is the most common cause of detection
failure because the sensor must be properly aimed at the target
within its rated sensing range.
2. A technician measures 128 V AC between two legs of a three-phase
supply and 208 V AC between each leg and neutral. What type of
three-phase system is this?
A. 480Y/277 V
B. 120/208Y V
C. 240 V Delta
, D. 600 V Delta
A 120/208Y system has 120 V phase-to-neutral and 208 V
phase-to-phase, fitting the measured values.
3. Which component in a programmable logic controller (PLC)
environment is responsible for converting real-world signals into logic
the CPU can process?
A. Power supply
B. CPU
C. Input/Output (I/O) module
D. Communication bus
I/O modules translate field device signals into digital data the PLC
CPU can interpret and act upon.
4. In motor control circuitry, what is the primary function of a contactor?
A. Provide overload protection
B. Control motor startup and shutdown
C. Measure motor current
D. Boost voltage to the motor
Contactors are electromechanical switches used to make or break
power to motors under control logic.
5. A temperature transmitter with a 4–20 mA output reads 5.2 mA with
the process at 50 % of span. What is the most likely cause?
A. Broken wiring
B. Power supply overload
C. Incorrect transmitter calibration
D. Faulty process connection
An output significantly below expected for mid-range typically
indicates calibration errors in the transmitter electronics.
6. In hydraulic systems, what does the term “dead-heading” refer to?
A. Leakage in return line
, B. Low fluid viscosity
C. Blocking actuator movement against pressure
D. Cavitation at pump inlet
Dead-heading describes a hydraulic actuator being prevented from
moving while fluid continues to be pumped, causing high pressure.
7. Which safety device will protect a three-phase motor from sustained
overcurrent?
A. Fuse
B. Pushbutton
C. Relay
D. Overload relay
Overload relays are designed to open the control circuit when motor
current remains high for a specified time to prevent overheating.
8. A ladder logic rung reads: XIC I:1/0 — OTE O:2/3. When input I:1/0 is
energized, what happens?
A. Output O:2/3 toggles
B. Timer starts running
C. Output O:2/3 energizes
D. Input is de-energized
An XIC (Examine If Closed) checks if the input is true, and with OTE
(Output Energize), if true the output is turned on.
9. A variable frequency drive (VFD) is installed and the motor hums but
doesn’t turn. What is the MOST likely issue?
A. VFD is underpowered
B. Motor is phased correctly
C. Control wiring is misconfigured
D. Drive ground fault
If the drive shows hum but no motion, control wiring or parameter
