Specifications

RailCorp Engineering Manual — Signals — Equipment Manual

Cerberus Level Crossing Monitor Field Equipment Manual TMG E1261

Issued August 2012 UNCONTROLLED WHEN PRINTED Version 2.1

For a 50 volt VIO terminals 3 and 4 conduct when the voltage across terminals 1 and 2 is

greater than 25 volts. Terminals 3 and 4 are high resistance when the voltage across

terminals 1 and 2 is less than 20 volts.

For a 12 volt VIO terminals 3 and 4 conduct when the voltage across terminals 1 and 2 is

greater than 8 volts. Terminals 3 and 4 are high resistance when the voltage across

terminals 1 and 2 is less than 6 volts.

2.4.4 Configuration and Set-up

The is no configuration or set-up except the appropriate volt unit is installed to the voltage

signalling circuit being monitored.

CAUTION

A 12V VIO must never be used on 50 volt Vital Signalling Circuits.

2.4.5 Troubleshooting

When the voltage across terminals 1 and 2 is less than 2 volts then the voltage across

terminals 3 and 4 should be equal to the voltage being switched on the indication circuit.

The indication circuit should be in the off state.

When the voltage across terminals 1 and 2 is close to the rated operating voltage (12V or

50V) the voltage across terminals 3 and 4 should be about 1.3 volts. The indication circuit

should be in the ON state.

In the case of the Flasher VIOs the circuit for terminals 3 and 4 is a 5 volt circuit (supplied

by the special flasher cable from Input 4 of the level crossing monitor). When the level

crossing lamps are off the voltage across 3, and 4 should be 5 volts. When the lights are

flashing the voltage across 3 and 4 should vary between 1 volt and 5 volts in sequence

with the flashing lamps.

If either of these cases is not correct then replace the unit.

Note: Terminals 1 and 3 should always be more positive than terminals 2 and 4.

2.4.6 Replacement

Disconnect the wiring from terminals 1 to 4. The wires connected to terminals 1 & 2 are

connected to vital signalling circuits and the appropriate procedures must be followed for

modifications to vital signalling circuits. Make sure these wires are identified and will not

be shorted out. Unclip the VIO from the Klippon rail. Clip the replacement to the Klippon

rail. Terminate the wiring back on to terminals 1 to 4.

CAUTION

Ensure that the replacement unit is same voltage as the unit being

replaced. Ensure that a 12V VIO is not being used on 50 volt Vital Signalling

Circuit.