Lascells RCCB Demo

Residual current circuit breakers (RCCBs), which are also known as Residual Current Devices (RCDs) use an electronic sensing circuit to monitor the mains electrical system, and when a fault occurs a trip switch is operated to disconnect the supply. In a domestic electrical system, MCBs are usually used to protect the individual circuits, with an RCCB used to monitor the entire installation. The RCCB monitors current leakage to Earth and disconnects the supply if a fault condition is detected. This approach is often used on the main isolation switch, and for protecting appliances used outside where water presents an additional hazard.
This apparatus demonstrates the action, and shows all the working parts of, a modern RCCB as used in domestic consumer units. The apparatus is contained within a robust plastic tray with protective acrylic cover and includes a clear circuit layout on the main panel. Applications of electromagnetism (movement from a solenoid) are clearly demonstrated as well as the performance of the RCCB itself.
The apparatus requires a 12V a.c. supply (and an oscilloscope if signal monitoring is required). A switch on the main panel is used to create a leakage path to ‘Earth’, and this produces an immediate response from the solenoid to disconnect the supply. The solenoid can be disabled to allow for a more detailed analysis of the action.
This apparatus is a companion to the Circuit Breaker Demonstration (ELP-375-100), and should prove invaluable to those wishing to show how this type of device operates as well as for teachers requiring an additional aid to show applications of electromagnetic devices.
Dimensions: 285 x 200 x 80 mm (l x w x h). Weight: 0.900 kg.

Applications include:
• Magnetic effect of a current
• Electro-mechanical devices
• Domestic electricity