The ABB 2CSB804101R4000 is a DDA804 residual current device (RCD) block from the DDA800 range. It assembles on site onto an ABB S800 series miniature circuit breaker and adds residual-current protection to that breaker's overcurrent protection. Building a board this way means the earth-fault function can be added only to the ways that need it, instead of holding a separate RCBO in every rating. It is 4-pole, rated 100 A, with a rated residual current of 500 mA. Type A means it responds to sinusoidal AC residual currents and to pulsating DC residual currents, which is what circuits feeding electronic loads require. At 500 mA it is intended for protection against earth-fault fire and for equipment protection, not for protection against direct contact — that requires a 30 mA device. It has an instantaneous tripping characteristic. Rated voltage 230/400 V AC; 240/415 V AC; 400/690 V AC. It fits S800S, S800N, S800C and S800B miniature circuit breakers. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.