T.EL.FER. develops a wide range of multifunctional direct-current (DC) protection relays, and current and voltage transducers for the DC traction market for trains, metros, tramways and trolleybuses.

We also produce low-power, low-voltage, ultra-high insulation DC/DC converters, voltage and current recorders, minimum voltage relays and thermal image relays.

Our products are approved by Rete Ferroviaria Italiana (RFI) and we have a quality system that meets UNI EN ISO 9001: 2008 standards.

DC traction protection relays for railway operations

T.EL.FER’s TF-RP21 high-performance DC protection relay comprises two 32 bit processors and a digital signal processor (DSP), in order to quickly detect failures and effectively protect rail lines.

The TF-RP21 is T.EL.FER’s high-performance DC traction protection relay.
The TF-IT thermal image relay comes with an environment temperature sensor.
The image shows the universal receiver / converter for TF-LP and TF-PROBE transducers.
The TF-UI 0505 DC/DC converter enables high insulation in a compact unit.
The TF-RP1X DC traction protection relay measures line voltages, currents and other parameters.
The high-reliability TF-PROBE current and voltage transducer features 16-bit resolution and redundant measurement channels with real-time congruency checks.
TF-LP DC current, voltage and current / voltage transducer is designed to work with the TF-CONV receiver.

The optional integrated programmable logic controller (PLC) allows the implementation of customised automatisation functions. The device allows direct fibre-optic connection with our current and voltage transducers.

Our DC protection relay implements a wide range of protection thresholds such as current and voltage levels, overhead line temperatures, maximum current variations, and switchboard or cable earth faults.

The TF-RP21 is also able to record a wide range of values with a one-minute resolution for up to three months, including supplied and input energies, as well as maximum and minimum voltages and currents.

The device can store up to 60 three-second, oscilloperturbographic recordings with a 125-microsecond resolution of both analogue and digital signals, allowing a deep analysis of any event, with an accurate time-relationship between all signals.

The TF-RP21NM can record currents and voltages with resolutions from 1ms to 499ms, or current, voltage and energy levels with resolutions ranging from 500ms to 10s onto a 32GB USB.

Relays for DC traction protection on rail lines

Our TF-RP1X three-analogue channel protection relay is available in several firmware versions to enable several protection function combinations.

All models offer:

  • Measurements of line voltage and current or other relevant parameters
  • Oscillographic event recordings
  • A self-diagnostic, Modbus interface
  • A user-friendly interface
  • An alphanumeric display with two lines of 16 characters to clearly display values and events
  • Capture and visualisation capabilities of oscilloperturbographic recordings
  • A continuous self-test function with remote signalling of malfunctions

DC current / voltage transducers

T.EL.FER’s TF-LP optical fibre transducers and TF-CONV receivers are designed to operate together in order to achieve a compact, affordable and economic measurement system.

They can measure either / both current and voltage levels on 1,500V lines or 3,000V lines. Devices are easily configurable on-site and the large power supply range (from 80VDC to 260VDC, or between 24VDC to 56VDC) makes them simple to install and operate.

TF-CONV receivers convert measurements received from optical fibre to current loop informations and display them on a six-digit high-brightness display.

TF-LP transducers can be connected directly through optical fibre to the TF-RP21 traction protection relays.

High-reliability current and voltage transducers for rail operations

The TF-PROBE I and V transducers feature 16bit resolution and redundant measurement channels with real-time congruency checks for 3,000V lines.

The PROBE-I also offers protection against overvoltage applied on shunt terminals up to 6kV. The transducers have optical fibre output and can be directly connected to a TF-RP21 relay or a TF-CONV receiver.

Thermal image relays for line test resistors

The TF-IT thermal image relay measures the current flowing into a load resistor through a Hall sensor. It also calculates the temperature reached by the resistor and signals when a programmable threshold has been passed.

It features programmable physical characteristics of the resistor and is equipped with an environment temperature sensor.

Ultra-high insulation DC/DC converters for railways

Our TF-UI 0505 DC/DC converter is a new proprietary technology that allows high insulation levels in a small, lightweight device.

Features and capacities include:

  • A 1.7W DC/DC converter
  • Input: between 4.85VDC and 6.5VDC
  • Output: 5VDC +/- 1%
  • Insulation: 25kVAC RMS