HVITC Track Circuit

HVITC Track Circuit

The main function of a track circuit is to detect the presence or absence of traffic on a given railway section of track. High voltage impulse track circuit (HVITC) designed and manufactured by ACTOM Transport, is a comprehensive range of jointed track circuit products, which can be adapted to any kind of track configuration.

An HVITC includes:

  • A transmitter, which generates impulses with a given shape, amplitude and recurrence frequency injected into the tracks by means of a matching isolating transformer
  • A receiver, which detects at the other end of the track section the specific signal and operates the failsafe relay, if the specific signal responds to the correct positive and negative amplitudes.

Applications:

  • HVITC track circuits are adaptable to these applications
  • Single rail arrangement for a length between 18 m and 750 m
  • The length can be extended to 1 000 m, provided one transmitter per track circuit is used
  • Non-electrified lines
  • DC electrified lines with: 750 V, 1 500V, 3000 V traction
  • AC electrified lines with 25 kV, 50Hz or 60Hz 15kV, 162/3 Hz

Installation conditions:

  • Minimum ballast resistance from 0,6 – 2 ohm/km
  • Drop shunt from 0,15 – 1 ohm
  • Impulse recurrence frequencies: 3 Hz
  • Impulse width: 3 milliseconds
  • Voltage peak value: 100V
  • Current peak value: 100A
  • Standard length of track circuit (with ballast resistance equal to 2 x 2 ohm/km).

HVITC consists of the following basic elements:

  • Power supply: 110V-115VAC 50hz or 60Hz
  • Transmitter: Power 45 VA, 24VDC Voltage limits: +20% – 6%
  • Peak-to-peak max. ripple: 5%
  • Transmitter: 50 W for 24 V equipment
  • The receiver NCO RVT 600 consists of two integrating circuits. The first circuit receives energy from the negative part of the impulse; the second circuit receives energy from the positive part of the waveform.
  • Fail-safe thresholds, and different thresholds eliminate electrical disturbances.

Track relay: NCO CVTH 24.4.0.4. The NCO RVT 600 receiver and NCO CVTH track relay do not require any power. The energy is provided from the track signal.