1
SACA C-202 Electric Motor Control Systems ACTUAL
EXAM QUESTIONS AND ANSWERS 2026/2027 |
Certification Exam | Ladder Logic, Components &
Troubleshooting | Pass Guaranteed - A+ Graded
Section 1: Motor Control Components & Symbols (14 questions)
Q1: In a ladder logic diagram, a circle with the letters "CR" inside and a number (e.g., CR1)
represents a:
A. Circuit Breaker.
B. Control Relay coil. [CORRECT]
C. Current Resistor.
D. Capacitor Relay.
Correct Answer: B
Rationale: The standard symbol for a control relay coil is a circle, often labeled with "CR"
(Control Relay) or "K" (contactor) followed by a number for identification. Its contacts
elsewhere in the diagram will carry the same number. Circuit breakers use different symbols
(rectangular or specific IEC/NEMA shapes), resistors use zigzag lines, and "capacitor relay" is
not standard terminology.
Q2: Which NEMA symbol represents a normally closed (NC) pushbutton in its unactuated state?
A. Two parallel vertical lines with a diagonal line connecting them, slanting upward to the right
B. Two parallel vertical lines with a diagonal line connecting them, slanting downward to the
right, with a small gap indicating the contact is closed [CORRECT]
C. A single vertical line with a zigzag pattern
D. A circle with an "X" through it
Correct Answer: B
Rationale: NEMA symbols for pushbuttons show the contact state unactuated. An NC pushbutton
shows the contact closed (conducting) at rest, represented by the diagonal line making
connection. The NO pushbutton shows an open gap at rest. The diagonal slant direction indicates
the actuation direction, but the key is whether the circuit is complete (NC) or broken (NO) in the
resting state.
,2
Q3: A thermal overload relay uses which physical principle to protect a motor?
A. Magnetic field strength proportional to current
B. Heat generated by current passing through a bimetallic strip [CORRECT]
C. Voltage drop across a precision resistor
D. Inductive reactance changes with load
Correct Answer: B
Rationale: Thermal overload relays use a bimetallic strip that heats when motor current passes
through it. The two metals expand at different rates, causing the strip to bend and open the
overload contacts. This mimics the motor's heating characteristics. Magnetic principles (A) are
used in magnetic-only breakers, not thermal overloads. Voltage drop (C) is used in electronic
overloads, and inductive reactance (D) is not a protection principle.
Q4: [Select ALL that apply] Which of the following are types of proximity sensors commonly
used in motor control applications?
A. Inductive proximity sensors [CORRECT]
B. Capacitive proximity sensors [CORRECT]
C. Photoelectric sensors [CORRECT]
D. Ultrasonic proximity sensors [CORRECT]
E. Mechanical limit switches only
Correct Answers: A, B, C, D
Rationale: Inductive sensors detect metallic objects, capacitive detect most materials (including
non-metallic), photoelectric use light beams, and ultrasonic use sound waves—all are valid
proximity sensing technologies in industrial control. Mechanical limit switches (E) are contact-
based position sensors, not proximity sensors (which are non-contact).
Q5: In a ladder diagram, the number "2" appearing next to a contact (e.g., "CR2") indicates:
A. The contact is rated for 2 amps
B. The contact belongs to the control relay or device numbered 2 [CORRECT]
C. The contact is located on rung 2 of the ladder
D. The contact has 2 poles
Correct Answer: B
, 3
Rationale: In ladder logic numbering systems, the number identifies the parent device that
controls the contact. A contact labeled "CR2" is controlled by the coil of Control Relay 2. This
allows tracing of circuit operation across multiple rungs. Wire numbers (not contact numbers)
indicate physical location; ampacity and pole count are specifications, not reference
designations.
Q6: An IEC-style contactor symbol shows a rectangle with the main contacts inside and an "X"
drawn through the coil. The "X" indicates:
A. The coil is defective
B. The coil is AC-operated [CORRECT]
C. The coil is DC-operated
D. The contactor is locked out
Correct Answer: B
Rationale: IEC symbols use specific markings: an "X" through the coil indicates AC operation,
while a solid line or "=" symbol indicates DC operation. This distinction is critical for
replacement and troubleshooting, as AC and DC coils have different construction and cannot be
interchanged without circuit modification.
Q7: Which component would be represented by a symbol showing a coil with a diagonal arrow
through it and the letter "T"?
A. A reversing contactor
B. A timing relay (timer) coil [CORRECT]
C. A transformer
D. A transient suppressor
Correct Answer: B
Rationale: The diagonal arrow through a coil symbol indicates a timing function, and "T"
designates a timer. This distinguishes it from standard control relays. Reversing contactors (A)
use mechanical or electrical interlock symbols, transformers (C) use two coils with shared lines,
and transient suppressors (D) appear as separate components across coils.
Q8: [Select ALL that apply] Which symbols would typically appear on the power circuit (as
opposed to control circuit) of a motor starter diagram?
A. Three-phase lines L1, L2, L3 [CORRECT]
B. Fused disconnect or circuit breaker [CORRECT]
SACA C-202 Electric Motor Control Systems ACTUAL
EXAM QUESTIONS AND ANSWERS 2026/2027 |
Certification Exam | Ladder Logic, Components &
Troubleshooting | Pass Guaranteed - A+ Graded
Section 1: Motor Control Components & Symbols (14 questions)
Q1: In a ladder logic diagram, a circle with the letters "CR" inside and a number (e.g., CR1)
represents a:
A. Circuit Breaker.
B. Control Relay coil. [CORRECT]
C. Current Resistor.
D. Capacitor Relay.
Correct Answer: B
Rationale: The standard symbol for a control relay coil is a circle, often labeled with "CR"
(Control Relay) or "K" (contactor) followed by a number for identification. Its contacts
elsewhere in the diagram will carry the same number. Circuit breakers use different symbols
(rectangular or specific IEC/NEMA shapes), resistors use zigzag lines, and "capacitor relay" is
not standard terminology.
Q2: Which NEMA symbol represents a normally closed (NC) pushbutton in its unactuated state?
A. Two parallel vertical lines with a diagonal line connecting them, slanting upward to the right
B. Two parallel vertical lines with a diagonal line connecting them, slanting downward to the
right, with a small gap indicating the contact is closed [CORRECT]
C. A single vertical line with a zigzag pattern
D. A circle with an "X" through it
Correct Answer: B
Rationale: NEMA symbols for pushbuttons show the contact state unactuated. An NC pushbutton
shows the contact closed (conducting) at rest, represented by the diagonal line making
connection. The NO pushbutton shows an open gap at rest. The diagonal slant direction indicates
the actuation direction, but the key is whether the circuit is complete (NC) or broken (NO) in the
resting state.
,2
Q3: A thermal overload relay uses which physical principle to protect a motor?
A. Magnetic field strength proportional to current
B. Heat generated by current passing through a bimetallic strip [CORRECT]
C. Voltage drop across a precision resistor
D. Inductive reactance changes with load
Correct Answer: B
Rationale: Thermal overload relays use a bimetallic strip that heats when motor current passes
through it. The two metals expand at different rates, causing the strip to bend and open the
overload contacts. This mimics the motor's heating characteristics. Magnetic principles (A) are
used in magnetic-only breakers, not thermal overloads. Voltage drop (C) is used in electronic
overloads, and inductive reactance (D) is not a protection principle.
Q4: [Select ALL that apply] Which of the following are types of proximity sensors commonly
used in motor control applications?
A. Inductive proximity sensors [CORRECT]
B. Capacitive proximity sensors [CORRECT]
C. Photoelectric sensors [CORRECT]
D. Ultrasonic proximity sensors [CORRECT]
E. Mechanical limit switches only
Correct Answers: A, B, C, D
Rationale: Inductive sensors detect metallic objects, capacitive detect most materials (including
non-metallic), photoelectric use light beams, and ultrasonic use sound waves—all are valid
proximity sensing technologies in industrial control. Mechanical limit switches (E) are contact-
based position sensors, not proximity sensors (which are non-contact).
Q5: In a ladder diagram, the number "2" appearing next to a contact (e.g., "CR2") indicates:
A. The contact is rated for 2 amps
B. The contact belongs to the control relay or device numbered 2 [CORRECT]
C. The contact is located on rung 2 of the ladder
D. The contact has 2 poles
Correct Answer: B
, 3
Rationale: In ladder logic numbering systems, the number identifies the parent device that
controls the contact. A contact labeled "CR2" is controlled by the coil of Control Relay 2. This
allows tracing of circuit operation across multiple rungs. Wire numbers (not contact numbers)
indicate physical location; ampacity and pole count are specifications, not reference
designations.
Q6: An IEC-style contactor symbol shows a rectangle with the main contacts inside and an "X"
drawn through the coil. The "X" indicates:
A. The coil is defective
B. The coil is AC-operated [CORRECT]
C. The coil is DC-operated
D. The contactor is locked out
Correct Answer: B
Rationale: IEC symbols use specific markings: an "X" through the coil indicates AC operation,
while a solid line or "=" symbol indicates DC operation. This distinction is critical for
replacement and troubleshooting, as AC and DC coils have different construction and cannot be
interchanged without circuit modification.
Q7: Which component would be represented by a symbol showing a coil with a diagonal arrow
through it and the letter "T"?
A. A reversing contactor
B. A timing relay (timer) coil [CORRECT]
C. A transformer
D. A transient suppressor
Correct Answer: B
Rationale: The diagonal arrow through a coil symbol indicates a timing function, and "T"
designates a timer. This distinguishes it from standard control relays. Reversing contactors (A)
use mechanical or electrical interlock symbols, transformers (C) use two coils with shared lines,
and transient suppressors (D) appear as separate components across coils.
Q8: [Select ALL that apply] Which symbols would typically appear on the power circuit (as
opposed to control circuit) of a motor starter diagram?
A. Three-phase lines L1, L2, L3 [CORRECT]
B. Fused disconnect or circuit breaker [CORRECT]
