Wavetronix VDR24 Radar - Manual (Page 69)

Support, Maintenance, Troubleshooting
VDR24 Radar Detection System, Rev. 1.0 69
9.1.12. Verification of Voltage Levels
9.1.12.1. Input Voltage
Verify proper input voltage to the VDR24 at the BAT+ and BAT- terminals located on the right
side of the VDR24. Although the VDR24 can continue to operate from an input voltage as low
as 8 volts and as high as 30 volts, the input voltage should ideally be 12 volts +/- 2 volts.
9.1.12.2. Radar Voltage
Refer to section 7.3.3 of this document for guidance on how to measure radar sensor voltages
supplied by the VDR24 to the sensors. Although the radar sensors can operate on as low as 12
volts, a normally operating VDR24 with adequate input voltage and source current should be
supplying a nominal 24.5 volts to the sensors.
9.1.13. Ground Leakage
It is always important to verify that there is no leakage path to earth ground, to assure AREMA
compliant isolation between the crossing warning system battery supply (B12+ and B12-), and
earth ground. Follow standard rules and procedures for verifying required levels isolation in
accordance with your organizations standards and practices.
9.1.14. Re-Tighten Radar Mounting Hardware
At least annually, it is recommended that the hardware securing the radar sensors be checked
to be sure that neither the straps securing the sensor mounting brackets to the masts or any of
the eight (8) bolts and nuts that hold the radar sensor in position are loose.
Refer to section 4 for detailed instructions on securing radar sensors into position.
9.1.15. Check Radar Electrical Connections
9.1.15.1. Communications Cable and Connector
Verify that the communications cable and connector show no signs of wear or damage. Verify
that the communications cable weatherproof connector is rotated clockwise and securely mated
with the receptacle on the radar sensor body. At the junction box where the mast cable
connects to home run cable, verify that there is no wearing of the cable jacket and that
weatherproof gaskets on the junction box are securely tightened.
9.1.15.2. Earth Ground
Also verify that the earth ground connector is securely screwed to the earth ground lug on the
bottom side of the radar housing. Also verify that the earth ground wire is securely connected
to an adequate earth ground connection at the mast base.
9.1.15.3. Cable Protection
Be certain that there are no signs of visible wear on any part of the mast cable or exposed
portions of home run cable. Cables should be bundled together using tie wraps or similar
mechanisms. There should enough slack to avoid straining the cables, but not enough would
cause significant movement due to wind.
9.1.16. Configuration Re-Verification
At least annually, repeat the tests set out in section 8.5, to verify that actual test vehicles
simulating the behavior of vehicles that may be queued in the crossing are properly detected.
These tests, initially conducted to verify the configuration process, also verify the entire system’s
response to detected vehicles during a crossing warning system activation as well as over all
system response to radar or VDR24 health failures.