Timeguard TX2420C 20A 30mA Type A C-Curve Solid Neutral RCBO

The Timeguard TX2420C 20A 30mA Type A RCBO combines overload, short-circuit and residual-current protection in one compact device. Designed for Timeguard TX series consumer units, it has a C-curve overcurrent characteristic, a 6kA breaking capacity and a single-module housing.

It is an option for electricians selecting protective devices for a compatible installation or replacing an existing RCBO where the circuit requires these exact characteristics.

Understand Type A and C-curve

The two classifications describe different functions. Type A residual-current protection responds to sinusoidal AC and pulsating DC residual currents. C-curve describes the overcurrent operating characteristic.

Compared with an equivalent B-curve device, C-curve has a higher instantaneous magnetic operating threshold. This can accommodate brief starting currents where the equipment and circuit design support its use. The rated circuit current remains 20A.

Solid neutral and unidirectional operation

This model has a solid neutral, which remains connected when the protected line pole opens. It should be distinguished from a switched-neutral RCBO when checking the installation’s isolation requirements.

The device is also unidirectional. Supply and load connections must follow the manufacturer’s markings, and it must not be selected for a circuit requiring bidirectional power flow.

Practical terminals and maintenance features

Top terminals accept conductors up to 10mm², with a specified tightening torque of 1.2Nm. Bottom terminals accept up to 25mm², with a tightening torque of 2.5Nm.

Terminal blanking plates help prevent incorrect cable or busbar insertion. A test button and contact position indicator are included, and the RCBO can be removed without removing the busbar once the assembly has been safely isolated