TN monitoring device LINETRAXX® MRCDB423

electrical safetyfor medical IT systems

The AC/DC sensitive MRCDB423 with the corresponding CTUB101-CTBC… measuring current transformers are used as additional protection (protection against indirect contact) in earthed systems (TN and TT systems) in which AC or DC fault currents may occur. Part of these systems are particularly loads containing six-pulse rectifiers or one-way rectifiers with smoothing, such as converters, battery chargers, construction site equipment with frequency-controlled drives. Since the values are measured with measuring current transformers, the MRCDB423 is almost independent of the nominal voltage and the operating current of the monitored system. The residual operating current IΔn2, the response delay ton2 as well as the currently measured residual current IΔ are shown on the standard display. By using an MRCDB423 with a suitable current transformer and a switching element with isolating properties, the device combination fulfils the requirements of IEC 60947-2 Annex M for an MRCD protective device. The application is specifically intended for protection goals such as protection of persons, fire protection and plant protection. The switching element must not exceed a switch-off time of 17 ms.