IMSA WORK ZONE SAFETY EXAM PREP ALL VERSIONS FINAL PACK EXAM
QUESTIONS AND CORRECT ANSWERS| 100% CORRECT| GRADED A+| ASSURED
100% PASS
IMSA Traffic Signal Technician
In a TS2 cabinet, how many times can the MMU experience a "Port 1 Fail" in a 24 hour period
before
the fault is latched? - ✔ANSWER 1
On a 2070 MMU monitor unit, how does the field tech program allowable phases? - ✔ANSWER
Remove diode on program card for allowable phases
On an MMU, is it possible to tape the reset button to prevent the traffic signal from going into
flash? - ✔ANSWER Yes, it by-passes the conflict feature and will not flash
On a NEMA CMU program card, how does the signal tech program allowable phases? -
✔ANSWER Install copper jumpers and soldering them on the program card
According to best maintenance practices, how often should CMU/MMU be tested? - ✔ANSWER
Annually
The MMU indicates a RED-FAIL fault on phase 6. Why? - ✔ANSWER The load switch/switch
pack produces no outputs.
The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the - ✔ANSWER Controller health
, When a Technician is recertifying the CMU/MMU at an intersection, what should the technician
do to have the intersection exit flash? - ✔ANSWER Replace the CMU/MMU with a newly
tested unit
Absence of all colors on a load switch will be indicated by what fault on an MMU or MMU2? -
✔ANSWER Red Fail
Which of the following can be programmed on an MMU to latch after a fault occurs? -
✔ANSWER Field check
How often is an MMU's clock updated from the controller? - ✔ANSWER Once a second
In a signal cabinet, on the signal monitor, what does a field check indicate? - ✔ANSWER The
signal indications don't match the controller output for a phase
A NEMA CMU/MMU uses a program card to tell the monitor which phases are permitted to run
together. Which answer is CORRECT? - ✔ANSWER NEMA monitors have wire jumpers
missing in all positions, the tech solders the ones in that allow phases to run together.
When the controller timings DO NOT match the timing sheet, who should be contacted for
correct
times? - ✔ANSWER Traffic Engineer
An older TS1 cabinet experiences a flash condition but the signal heads are also showing active
green, yellow, and red indications. What is the MOST COMMON issue? - ✔ANSWER The
mercury contactor is stuck in the normal position.
In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring at the
same
time? - ✔ANSWER 1
, Observations indicate that vehicles are being detected in one lane and that this is shown on the
detection interface unit. However, the controller does not show any detection for that phase.
This could be caused by - ✔ANSWER Improper detection phase assignment programming in
the controller
As soon as vehicles leave the detection zone of an approach that has met its minimum green
time, a signal immediately goes to yellow from the green display. This could be a result of -
✔ANSWER no extension time programmed.
What is one reason the phase interval may change even though there is still vehicle demand? -
✔ANSWER maximum green time has been met
A signal tech is reviewing the controller logs and continually sees a cycle fault error. What does
that
mean? - ✔ANSWER The CU has not serviced a call in two cycles while in free mode.
A coordinated corridor is working well except at one intersection where a platoon of vehicles is
being stopped. The MOST LIKELY problem is the - ✔ANSWER clock has drifted affecting the
offset and needs adjusting
Observations indicate that right turning vehicles approach the intersection on the side street,
stop and then make a right turn on red. When this happens the signals cycle to the side street
even though there are no longer vehicles present in the detection zone. This could be caused by
- ✔ANSWER the detection being set to locking detection
Of the following, which answer MOST LIKELY would require a controller database be verified to
be
correct? - ✔ANSWER When a controller upgrade has been performed
, Which offset mode is the easiest way to view progression in a coordinated corridor? -
✔ANSWER Beginning of green
Why is it important for a Signal Tech to verify that the phase concurrency is the same in the
controller as it is in the MMU or ATC CMU? - ✔ANSWER The MMU/CMU will keep the
cabinet in flash until MMU mirrors what is programmed in the controller
NEMA Standard TS2-2003 requires all but which of these detector faults to be reported to the
controller? - ✔ANSWER Erratic counts
Observations indicate that a phase is extending to maximum green on every cycle despite no
vehicles being present in the detection zone. This could be caused by - ✔ANSWER a
damaged loop detector for that phase
A Tech is troubleshooting a cabinet where the controller is reporting a cycle fail. What does that
mean? - ✔ANSWER There is more time in the sum of the splits than the time programmed
for the first cycle.
An intersection goes into flash every morning at exactly the same time. Which of the following
is the LEAST IMPORTANT piece of data that can be retrieved from the cabinet? - ✔ANSWER
Controller Voltage
If a Signal Tech is required to change a timing parameter in the controller, it is MOST
IMPORTANT to
do which of the following? - ✔ANSWER Alert their supervisor of the changes made
A signal tech sees that the detection is working properly at the detection device, and is
connected to the controller but the controller does not get the input. What could be one of the
issues preventing the detection from getting to the controller? - ✔ANSWER The detector is
not mapped in the controller correctly.
QUESTIONS AND CORRECT ANSWERS| 100% CORRECT| GRADED A+| ASSURED
100% PASS
IMSA Traffic Signal Technician
In a TS2 cabinet, how many times can the MMU experience a "Port 1 Fail" in a 24 hour period
before
the fault is latched? - ✔ANSWER 1
On a 2070 MMU monitor unit, how does the field tech program allowable phases? - ✔ANSWER
Remove diode on program card for allowable phases
On an MMU, is it possible to tape the reset button to prevent the traffic signal from going into
flash? - ✔ANSWER Yes, it by-passes the conflict feature and will not flash
On a NEMA CMU program card, how does the signal tech program allowable phases? -
✔ANSWER Install copper jumpers and soldering them on the program card
According to best maintenance practices, how often should CMU/MMU be tested? - ✔ANSWER
Annually
The MMU indicates a RED-FAIL fault on phase 6. Why? - ✔ANSWER The load switch/switch
pack produces no outputs.
The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the - ✔ANSWER Controller health
, When a Technician is recertifying the CMU/MMU at an intersection, what should the technician
do to have the intersection exit flash? - ✔ANSWER Replace the CMU/MMU with a newly
tested unit
Absence of all colors on a load switch will be indicated by what fault on an MMU or MMU2? -
✔ANSWER Red Fail
Which of the following can be programmed on an MMU to latch after a fault occurs? -
✔ANSWER Field check
How often is an MMU's clock updated from the controller? - ✔ANSWER Once a second
In a signal cabinet, on the signal monitor, what does a field check indicate? - ✔ANSWER The
signal indications don't match the controller output for a phase
A NEMA CMU/MMU uses a program card to tell the monitor which phases are permitted to run
together. Which answer is CORRECT? - ✔ANSWER NEMA monitors have wire jumpers
missing in all positions, the tech solders the ones in that allow phases to run together.
When the controller timings DO NOT match the timing sheet, who should be contacted for
correct
times? - ✔ANSWER Traffic Engineer
An older TS1 cabinet experiences a flash condition but the signal heads are also showing active
green, yellow, and red indications. What is the MOST COMMON issue? - ✔ANSWER The
mercury contactor is stuck in the normal position.
In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring at the
same
time? - ✔ANSWER 1
, Observations indicate that vehicles are being detected in one lane and that this is shown on the
detection interface unit. However, the controller does not show any detection for that phase.
This could be caused by - ✔ANSWER Improper detection phase assignment programming in
the controller
As soon as vehicles leave the detection zone of an approach that has met its minimum green
time, a signal immediately goes to yellow from the green display. This could be a result of -
✔ANSWER no extension time programmed.
What is one reason the phase interval may change even though there is still vehicle demand? -
✔ANSWER maximum green time has been met
A signal tech is reviewing the controller logs and continually sees a cycle fault error. What does
that
mean? - ✔ANSWER The CU has not serviced a call in two cycles while in free mode.
A coordinated corridor is working well except at one intersection where a platoon of vehicles is
being stopped. The MOST LIKELY problem is the - ✔ANSWER clock has drifted affecting the
offset and needs adjusting
Observations indicate that right turning vehicles approach the intersection on the side street,
stop and then make a right turn on red. When this happens the signals cycle to the side street
even though there are no longer vehicles present in the detection zone. This could be caused by
- ✔ANSWER the detection being set to locking detection
Of the following, which answer MOST LIKELY would require a controller database be verified to
be
correct? - ✔ANSWER When a controller upgrade has been performed
, Which offset mode is the easiest way to view progression in a coordinated corridor? -
✔ANSWER Beginning of green
Why is it important for a Signal Tech to verify that the phase concurrency is the same in the
controller as it is in the MMU or ATC CMU? - ✔ANSWER The MMU/CMU will keep the
cabinet in flash until MMU mirrors what is programmed in the controller
NEMA Standard TS2-2003 requires all but which of these detector faults to be reported to the
controller? - ✔ANSWER Erratic counts
Observations indicate that a phase is extending to maximum green on every cycle despite no
vehicles being present in the detection zone. This could be caused by - ✔ANSWER a
damaged loop detector for that phase
A Tech is troubleshooting a cabinet where the controller is reporting a cycle fail. What does that
mean? - ✔ANSWER There is more time in the sum of the splits than the time programmed
for the first cycle.
An intersection goes into flash every morning at exactly the same time. Which of the following
is the LEAST IMPORTANT piece of data that can be retrieved from the cabinet? - ✔ANSWER
Controller Voltage
If a Signal Tech is required to change a timing parameter in the controller, it is MOST
IMPORTANT to
do which of the following? - ✔ANSWER Alert their supervisor of the changes made
A signal tech sees that the detection is working properly at the detection device, and is
connected to the controller but the controller does not get the input. What could be one of the
issues preventing the detection from getting to the controller? - ✔ANSWER The detector is
not mapped in the controller correctly.
