TBC THA-240 Type A Residual Current Circuit Breaker (RCCB) 2P 40A 30mA

The THA-240 operates using a toroidal current transformer that continuously monitors the differential current between the line and neutral conductors. Under normal operating conditions, the vector sum of these currents is zero. When a residual current exceeding the 30mA sensitivity threshold is detected — whether sinusoidal AC or pulsating DC in nature — the electromagnetic release mechanism actuates the tripping assembly, disconnecting the circuit within the response time defined by IEC 61008-1. The device incorporates an impulse withstand current rating of 500A, providing resilience against transient surge events that could otherwise cause nuisance tripping. The 2-pole configuration simultaneously disconnects both line and neutral conductors, ensuring complete isolation of the protected circuit upon fault detection.

• Residential Distribution Boards: Protection of final circuits in homes, apartments, and landed properties against earth leakage and electric shock.
• Water Heater Circuits: Essential protection for instantaneous and storage water heater installations where water and electricity proximity presents elevated shock risk.
• Kitchen Appliance Circuits: Safeguarding circuits supplying refrigerators, dishwashers, washing machines, and other household appliances with electronic control boards.
• Office Electrical Systems: Earth leakage protection for workstation, lighting, and general power circuits in commercial office environments.
• Shoplots and Light Commercial Premises: Suitable for retail outlets, food and beverage establishments, and small commercial units requiring reliable leakage protection.
• Air-Conditioning Circuits: Protection of split-unit and inverter air-conditioning systems that generate pulsating DC residual currents requiring Type A detection.
• Bathroom and Wet Area Circuits: Compliance with electrical safety requirements for circuits in zones with increased moisture exposure.