Voltage Frequency Protection Relay

TARD

Current Transformers

RD Family Accessories

Toroidal Transformers (TARD) can be combined with the RD family of Earth Leakage Relays to detect current leakages due to loss of ground insulation. The TARD must be installed so that all active wires go through its windows (L1, L2, L3, N). This means that any screen or rumour must not pass through. This guarantees that the ELR receives a signal proportional to the vectorial sum of the lines and neutral currents.

The secondary coil insulation is guaranteed by a 2.5 kV test at main frequency for 1 minute. 

The TARD are made in highly permeable magnetic materials and are available with internal diameters from 35 mm to 210 mm in closed or open format, allowing the installation on bars and cables up to considerable dimensions. The enclosure is made with insulating and fire retardant covers, provided with accessories for the fixing on DIN guides. The connection between the RD and the TARD should be made with twisted shielded cables.

The connection length should be as short as possible and additionally far away from power cables and other devices that may cause electromagnetic noises.

Accessories

• Nominal Frequency: 47 to 63 Hz
  
  
• Ratio of measure winding: 500/1

• Insulation test: 2,5 kV 50/60 Hz (60 sec.)

• Working temperature: -10° to 55°

• Terminal blocks: 4.0 mm2 / 10 AWG

• Cover material: fire retardant plastic