Bender GmbH   RCMA423   The AC/DC sensitive residual current monitor RCMA423 is designed for monitoring earthed power supply systems (TN and TT systems) where smooth DC fault currents or residual currents continuously greater than zero may occur. These are in particular loads containing six-pulse rectifiers or one way rectifiers with smoothing, such as converters, battery charders, construction site equipment with frequency-controlled drives. Currents in single conductors can also be monitored by RCMA423. The prewarning stage (50...100 % of the set response value / Δn2 ) allow to distinguish between prewarning and alarm. Since the values are measured with measuring current transformers, the device is nearly independent of the load current and the nominal voltage of the system. Device features AC/DC sensitive residual current monitor Type B acc. to IEC 62020 and IEC/TR 60755 r.m.s. value measurement (AC+DC) Two separately adjustable response values 30...3 A Frequency range 0...2000 Hz Start-up delay, response delay and delay on release Digital measured value display via LC display Measured value memory for operating value CT connection monitorind LEDs: Power On, Alarm 1, Alarm 2 Internal / external test / reset button Two separate alarm relays (one changeover contact each) N/O or N/C operation and fault memory selectable Continuous self monitoring Multi-functional LC display Password prostection for device settings Sealable transparent cover Push-wire terminal (two terminals per connection) Two-module enclosure (36 mm)