IMSA Traffic Signal Technician Level II
Questions and Verified Answers
Grade A 100% Correct Update
1. 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
2. On a 2070 MMU monitor unit, how does the field tech program allowable phases?
Answer Remove diode on program card for allowable phases
3. 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
4. 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
5. According to best maintenance practices, how often should CMU/MMU be tested?
Answer Annually
6. The MMU indicates a RED-FAIL fault on phase 6.Why?
Answer The load switch/switch pack produces no outputs.
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,7. The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the
Answer Controller health
8. 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
9. Absence of all colors on a load switch will be indicated by what fault on an MMU or
MMU2?
Answer Red Fail
10. Which of the following can be programmed on an MMU to latch after a fault occurs?
Answer Field check
11. How often is an MMU's clock updated from the controller?
Answer Once a second
12. 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
13. A NEMA CMU/MMU uses a program card to tell the monitor which phases are
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, 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.
14. When the controller timings DO NOT match the timing sheet, who should be
contacted for correct
times?
Answer Traffic Engineer
15. 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.
16. In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring
at the same
time?
Answer 1
17. 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
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Questions and Verified Answers
Grade A 100% Correct Update
1. 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
2. On a 2070 MMU monitor unit, how does the field tech program allowable phases?
Answer Remove diode on program card for allowable phases
3. 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
4. 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
5. According to best maintenance practices, how often should CMU/MMU be tested?
Answer Annually
6. The MMU indicates a RED-FAIL fault on phase 6.Why?
Answer The load switch/switch pack produces no outputs.
1/
23
,7. The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the
Answer Controller health
8. 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
9. Absence of all colors on a load switch will be indicated by what fault on an MMU or
MMU2?
Answer Red Fail
10. Which of the following can be programmed on an MMU to latch after a fault occurs?
Answer Field check
11. How often is an MMU's clock updated from the controller?
Answer Once a second
12. 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
13. A NEMA CMU/MMU uses a program card to tell the monitor which phases are
2/
23
, 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.
14. When the controller timings DO NOT match the timing sheet, who should be
contacted for correct
times?
Answer Traffic Engineer
15. 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.
16. In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring
at the same
time?
Answer 1
17. 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
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23
