Appendix B: Maintenance Procedures for ITS Devices

The lists below include examples of preventive maintenance procedures for a variety of common device types. Maintenance staffs need to develop their own sets of procedures based on the devices they have and the information from the manufacturer. Keeping documentation of the procedures and when they are performed will put the Agency in a better position in the case of disputes concerning warranties and in providing the MTBF data discussed earlier.

Closed-Circuit Television Camera Preventive Maintenance

Camera Preventive Maintenance at Pole Level — Every Six Months

  • Check camera housing pressure (typically 5psi +/- 1psi). Pressurize with dry nitrogen if not within limits and document readings on sheet provided
  • Visually inspect camera housing
  • Clean glass with suitable glass cleaning agent
  • Inspect pan and tilt mechanism and adjust limit switches where applicable
  • Inspect housing mounting for corrosion.
  • Remove any bird nest around the camera housing following approval from the Environmental Department
  • Check and inspect the integrity of all cable harness and connectors. Replace defective item where applicable
  • Check integrity of surge protector - replace where applicable
  • Check wiper blades and wiper assembly unit - replace defective units
  • Replace filter in camera housing
  • Check operation of thermostat inside camera housing
  • Check for corrosion of terminal inside housing

Camera Preventive Maintenance at Cabinet Level — Every Three Months

  • Check integrity of all cables and connectors
  • Check raw video from the camera with a waveform monitor (raw video shall measure 1.00Vp/p). Adjust per specifications in specialty camera manual
  • Check all local functions (Pan, Tilt, Zoom in, Zoom out, Focus Far, Focus near)
  • Check integrity of surge protectors
  • Check and ensure that all relays are firmly seated on the control board
  • Check operation of auto-iris and adjust for correct operation per operational and maintenance manual
  • Check circuit box at the base of the camera pole to ensure that the terminal strips are corrosion free
  • Check proper function thermostat
  • Check fan and replace where applicable
  • Clean and vacuum inside of cabinet
  • Inspect and change filter where applicable
  • Check light bulb and replace where applicable.
  • Check incoming power for proper voltage and correct if not within tolerances
  • Check cabinet door for proper closure

Camera Preventive Maintenance at Control Center — Weekly

  • Using the waveform monitor, perform the following measurements and ensure that the results recorded are within manufacturers specifications. Document the results:
  • Check raw video
  • Measure peak white
  • Measure color burst
  • Measures synch pulse
  • Check integrity of all connectors
  • Check all camera video at night (to determine which cameras need back focusing)

Gates/Barriers System Preventive Maintenance

Preventive Maintenance at the Gate Cabinet – Every Three Months

  • Perform visual inspection of the high voltage side of the cabinet (Use extreme caution and observe all safety rules)
  • Check oil level - add oil if needed
  • Grease all grease nipples and wipe excess
  • Check for oil leaks in the gate housing
  • Test gate opening and closing sequence using the open and close buttons in the gate cabinet
  • Verify that the lights on the gate flash when the gate arm moves between opening and closing.
  • Verify that the lights stop flashing and remain on solid when the gate arm is in closed position
  • Verify that the lights stop flashing and remain off when the gate arm is in the open position
  • Turn off power to the gate cabinet and use hand crank to open or close gate (this is to ensure that the gate can be opened or closed in the event of power failure)
  • Replace all burnt out bulbs
  • Perform physical inspection of the gate arm and replace broken or rotten wood
  • Check reflectors and replace where necessary
  • Check adjust gate clearance from road surface
  • Check and adjust limit switches if needed

Preventive Maintenance at the Gate Control Cabinet — Every Three Months

  • Open and close gate group from control cabinet
  • Adjust gate opening and closing timing sequence
  • Check isolators associated with the controller for damage and repair or replace

Lane Control Signal Preventive Maintenance

The lane control signal preventive maintenance requires planning and coordination with control room. Since changing the "X" and arrow has impact on the traffic movement, it is important to set up traffic control for this operation.

Lane Control Signal from Control Room — Weekly

  • Check that all signal heads can be controlled from Central and document results

Lane Control Signal Local Field Control (from field) — Weekly

  • From each control cabinet in the field, verify that the signal heads can be changed
  • Document results
  • Clean cabinet interior
  • Replace filter if required

Lane Control Signs Preventive Maintenance — Every Three Months

  • Check and ensure that both lamps in the signal head are in good working order
  • Wipe and clean signal head
  • Check wiring and terminal block for corrosion. Replace where necessary

Dynamic Message Signs (DMS) Preventive Maintenance — Annually at the Sign; Every Three Months at the Cabinet

  • Photo Cell - clean photo cell aperture
  • Ventilation - clean filters
  • Lexan cleaning - clean front surface with approved detergent
  • Cabinet Filter - clean or change filters
  • Fans - check fan condition and thermostat settings
  • Vacuum cabinet and clean
  • Test - Row and Column Check
  • Test - All "ON" and ALL "OFF"
  • Test - check alpha numeric characters

Back up Battery Assemblies — Annually

  • String voltage - measure /record
  • Individual Voltages - measure /record
  • Pilot unit Voltage - measure /record
  • Ambient temperature - measure /record
  • Unit interconnection - inspect, clean, retorque
  • The unit must be cleaned quarterly to remove dust from covers.
  • If signs of corrosion, clean with a solution of baking soda and water or isopropyl alcohol
  • If corrosion reoccurs, report to the Department

Air Conditioning Unit Preventive Maintenance — Every Three Months

  • Air Filter - remove and clean or replace
  • Blower unit - check for bearing noise
  • Compressor - check functions - reset thermal overload
  • Refrigerant loss - check refrigerant level and pressure, check cracks & leaks in pipe lines

Spread Spectrum Preventive Maintenance — Annually

  • Check and inspect antenna in the field
  • Check antenna alignment (both receive and transmit end)
  • Measure antenna gain
  • Measure the VSWR (Voltage Standing Wave Ratio)

Ramp Meter Preventive Maintenance — Monthly

  • Check the operation of the Blank Out sign - replace any defective bulbs
  • Check the operation of the Ramp Controller - repair as needed
  • Check stop line and make sure that this is clearly visible - make notation for any line that is not visible and report immediately to road marking crew for remarking
  • Check advisory signs to ensure accurate words and facing the motorist
  • Check signal light head for correct operation
  • Replace any burnt out bulbs
  • Check and adjust signal head to face the correct direction
  • Check and adjust where necessary the ramp meter time clocks in accordance with schedules
  • Check the function of the QUEUE loop
  • Document all results on the ramp meter maintenance check list
  • Request control center to send command to turn on or off and verify

Loops and Piezo Detectors Preventive Maintenance

Loop Preventive Maintenance — Annually

At the Cabinet Level

  • Disconnect loop
  • With LCR meter measure and record inductance of the loop (L= µH)
  • With LCR meter measure and record resistance (R= ohms)
  • With a MEGGER meter measure and record the insulation resistance (100 meg >)
  • If readings are outside specification, disconnect lead-in at the splice box and check all three parameters at that level
  • From the readings determine whether loop or the lead-in need repair

Piezoelectric Detector Preventive Maintenance — Every Three Months

  • Check cracks in the asphalt at the shoulder
  • Check cracks in the sensor at the shoulder
  • Check cracks in the sensor at the wheel tracks
  • Check cracks at the sensor /asphalt interface
  • Using LCR meter measure capacitance (C= µF)
  • Using LCR meter measure resistance (R = ohms)
  • Use manufactures recommended procedure for checking detectors