Residual current monitoring relay Doepke

Residual current monitors (RCM) reliably detect and report fault and differential currents without switching off the system. They are used wherever the system cannot be switched off, or this is not desired. Series DRCM residual current monitors has a number of usable total current transformers and therefore also a number of conductor cross-sections or rated currents. The bar display provides a view of the current residual current. The alarm is triggered at a fixed response threshold. The current level of the residual current, and the point where the response thresholds are exceeded can be seen on a 10-way LED display on the front of the device housing. A faulty connection to the external residual current transformer is immediately indicated by the alarm LED through a flashing pattern and by the activation of the signal contacts. The adjustable response delay in the range from 0.1 s to 1 s (in increments of 100 ms) makes it possible to prevent a response to brief residual current impulses, e.g. lightning strikes and switching overvoltage. This approach allows for selectivity of devices switched in series, simplifying the localisation of faults. Two independent, potential-free changeover contacts provide the option of passing on the alarm to optional indicator panels, indicator lights, acoustic signalling devices, touch panels, PLCs, etc. Monitors with residual current characteristic A detect sinusoidal AC currents as well as pulsating DC residual currents. Devices in the standard design are intended for monitoring circuits with a rated voltage of 230 V and a rated frequency of 50 Hz. Properties: VDE-certified (DIN EN 62020); suitable for detecting type A residual currents; monitored frequency range 50-60 Hz; rated residual operating current adjustable in five levels (30, 100, 300, 1000 and 3000 mA); residual current transformers with internal diameters of 20, 30, 70 and 105 mm available; rated voltage of monitored circuit up to 690 V; fixed response threshold of alarm between 75% and 100% of the set rated residual operating current (Idn); adjustable pre-alarm threshold; alarm relays with two potential-free changeover contacts (230 V AC/5 A) selectivity adjustable in ten levels (0.1 s to 1 s in increments of 100 ms) dependent on auxiliary voltage; compact, robust plastic housing; easy mounting; Mounting: quick fastening to mounting rail; any installation position; Application areas: The monitoring device is suitable for use in power supplied to purpose-built buildings and industrial facilities with TN-S, TN-C-S networks and IT networks, such as in server rooms for data centres, laboratories, in the automotive industry and in conjunction with air conditioning systems, printing machines and packaging machines; Not permitted for use in TN-C networks and direct current networks; not permitted for monitoring systems in which electronic equipment may cause DC residual currents or residual currents with frequencies not equal to the rated frequency of the RCCB; Hints: RCMs may not be used to realise protective measure ‘Automatic switch-off of power supply’ as per DIN VDE 0100-410 (an RCM does not replace an RCD). Residual currents are detected separately by external residual current transformers from series DCT. which are ordered separately. No more than one transformer can be operated on one evaluation unit. The maximum cable length from the control relay to the transformer is 10 m.