CO Electrical Signs Contractor Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of a disconnecting means for an
electrically operated sign?
A. To increase the sign's brightness
B. To provide a convenient means of grounding the sign
C. To disconnect power from the sign for servicing and maintenance
D. To reduce the sign's operating voltage
Rationale: A disconnecting means allows the sign circuit to be safely
de-energized before inspection, maintenance, repair, or replacement.
It is an important part of electrical safety because workers should not
have to service energized equipment when de-energization is possible.
2. Which type of electrical sign commonly uses a high-voltage
transformer to illuminate gas-filled tubes?
,A. LED sign
B. Incandescent sign
C. Neon sign
D. Fiber-optic sign
Rationale: Traditional neon signs use gas-discharge tubes supplied by
a high-voltage transformer. The transformer raises the available
voltage to the level required to produce the electrical discharge that
illuminates the gas.
3. What is the main function of a sign's grounding conductor?
A. Increase current flow
B. Reduce lamp temperature
C. Provide a low-impedance path for fault current
D. Prevent the sign from becoming brighter
Rationale: The grounding conductor provides a path for fault current
back to the source so protective devices can operate quickly. This
helps prevent exposed metal parts from remaining energized at
dangerous voltages.
4. Before servicing an electrically illuminated sign, what should be
done first?
,A. Remove the lamps
B. Open the sign cabinet
C. De-energize the circuit and verify that it is de-energized
D. Disconnect the grounding conductor
Rationale: Electrical equipment should be de-energized before
servicing whenever practical. The worker should also verify the
absence of voltage with an appropriate test instrument rather than
relying solely on a switch or breaker position.
5. Which device is commonly used to protect a sign branch circuit
against overcurrent?
A. Thermostat
B. Photocell
C. Circuit breaker or fuse
D. Transformer tap
Rationale: Fuses and circuit breakers protect conductors and
equipment from excessive current. They are selected based on the
circuit characteristics and applicable electrical requirements.
6. What is the purpose of a photocell on an outdoor sign?
A. Increase transformer voltage
B. Control grounding resistance
, C. Automatically turn the sign on or off based on ambient light
D. Increase the sign's conductor size
Rationale: A photocell senses surrounding light levels. It can
automatically energize a sign when it becomes dark and de-energize it
when sufficient daylight is present.
7. Which condition is most likely to cause repeated tripping of a sign
circuit breaker?
A. Properly sized conductors
B. Correctly rated lamps
C. A short circuit or excessive circuit load
D. A properly adjusted photocell
Rationale: A breaker trips when current exceeds its permitted
operating level or when a fault occurs. A short circuit or overloaded
sign circuit can therefore cause repeated breaker operation.
8. Why should conductors entering a metal sign cabinet be
protected from sharp edges?
A. To increase conductor resistance
B. To improve the sign's appearance
C. To prevent insulation damage and possible grounding faults
D. To reduce lamp voltage
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of a disconnecting means for an
electrically operated sign?
A. To increase the sign's brightness
B. To provide a convenient means of grounding the sign
C. To disconnect power from the sign for servicing and maintenance
D. To reduce the sign's operating voltage
Rationale: A disconnecting means allows the sign circuit to be safely
de-energized before inspection, maintenance, repair, or replacement.
It is an important part of electrical safety because workers should not
have to service energized equipment when de-energization is possible.
2. Which type of electrical sign commonly uses a high-voltage
transformer to illuminate gas-filled tubes?
,A. LED sign
B. Incandescent sign
C. Neon sign
D. Fiber-optic sign
Rationale: Traditional neon signs use gas-discharge tubes supplied by
a high-voltage transformer. The transformer raises the available
voltage to the level required to produce the electrical discharge that
illuminates the gas.
3. What is the main function of a sign's grounding conductor?
A. Increase current flow
B. Reduce lamp temperature
C. Provide a low-impedance path for fault current
D. Prevent the sign from becoming brighter
Rationale: The grounding conductor provides a path for fault current
back to the source so protective devices can operate quickly. This
helps prevent exposed metal parts from remaining energized at
dangerous voltages.
4. Before servicing an electrically illuminated sign, what should be
done first?
,A. Remove the lamps
B. Open the sign cabinet
C. De-energize the circuit and verify that it is de-energized
D. Disconnect the grounding conductor
Rationale: Electrical equipment should be de-energized before
servicing whenever practical. The worker should also verify the
absence of voltage with an appropriate test instrument rather than
relying solely on a switch or breaker position.
5. Which device is commonly used to protect a sign branch circuit
against overcurrent?
A. Thermostat
B. Photocell
C. Circuit breaker or fuse
D. Transformer tap
Rationale: Fuses and circuit breakers protect conductors and
equipment from excessive current. They are selected based on the
circuit characteristics and applicable electrical requirements.
6. What is the purpose of a photocell on an outdoor sign?
A. Increase transformer voltage
B. Control grounding resistance
, C. Automatically turn the sign on or off based on ambient light
D. Increase the sign's conductor size
Rationale: A photocell senses surrounding light levels. It can
automatically energize a sign when it becomes dark and de-energize it
when sufficient daylight is present.
7. Which condition is most likely to cause repeated tripping of a sign
circuit breaker?
A. Properly sized conductors
B. Correctly rated lamps
C. A short circuit or excessive circuit load
D. A properly adjusted photocell
Rationale: A breaker trips when current exceeds its permitted
operating level or when a fault occurs. A short circuit or overloaded
sign circuit can therefore cause repeated breaker operation.
8. Why should conductors entering a metal sign cabinet be
protected from sharp edges?
A. To increase conductor resistance
B. To improve the sign's appearance
C. To prevent insulation damage and possible grounding faults
D. To reduce lamp voltage
