RTB035 Lovato TOROID CT EARTH LEAK. RELAY TYPE B D35MM

Why Choose the Lovato RTB035 Type B Toroidal Current Transformer?

The Lovato RTB035 is a Type B toroidal current transformer designed for use with compatible Lovato earth leakage relays. It provides residual-current sensing for electrical protection systems where Type B detection characteristics are required, making it an important component in earth leakage monitoring and protection applications.

Featuring a 35 mm internal diameter, the RTB035 allows the conductors of the monitored circuit to pass through the toroidal opening. The phases and neutral, when present, are routed through the transformer so that residual current can be detected by the connected compatible earth leakage relay, while the protective earth conductor must remain outside the toroid.

The RTB035 supports Type B residual operation and is suitable for systems requiring a 30 mA earth leakage relay threshold when used with compatible Lovato Type B relay equipment. Its compact dimensions, 322 g weight and conformity with IEC/EN/BS 60947-2 make it a practical sensing component for professional industrial and commercial electrical protection systems.

Key Advantages

• Designed specifically for Type B earth leakage protection systems.
• 35 mm internal aperture accommodates compatible monitored circuit conductors.
• Suitable for use with compatible Lovato Type B earth leakage relays.
• Supports applications with a 30 mA residual-current threshold when paired with compatible relay equipment.
• External toroidal sensing enables residual-current monitoring without being installed directly in the load current path.
• Conforms to IEC/EN/BS 60947-2.

Key Features

• Lovato RTB series toroidal current transformer.
• Type B residual operation characteristic.
• 35 mm (1.38 in) internal diameter.
• Designed for compatible external earth leakage relays.
• Suitable for 30 mA threshold applications with compatible Type B relay systems.
• All monitored live conductors, including neutral when present, pass through the toroid.
• Protective earth conductor remains outside the transformer aperture.
• Compact current-sensing solution for electrical protection installations.

Type B Earth Leakage Current Monitoring

A toroidal current transformer used with an earth leakage relay monitors the vector sum of the currents flowing through the conductors passing through its aperture. Under normal operating conditions these currents balance; when leakage to earth occurs, an imbalance is detected by the toroid and transmitted to the associated earth leakage relay for evaluation and protective action.

For correct operation of the RTB035, the conductors of the circuit being monitored must pass through the toroidal transformer, including all phases and the neutral conductor when present. The protective earth conductor must not pass through the toroid. Lovato also recommends keeping the toroid-to-relay connection away from power cables and minimising the connection distance to reduce susceptibility to electromagnetic interference.

Typical Applications

• Type B earth leakage relay systems.
• Industrial electrical distribution and control panels.
• Machinery requiring residual-current monitoring.
• Electrical installations containing power electronic equipment.
• Commercial and industrial low-voltage distribution systems.
• Applications requiring a 35 mm Type B toroidal current transformer.