DMRCD 1 A Hz pulsating AC/DC-sensitive type A, for frequencies ? 50 Hz0 pages

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DATA SHEET
DMRCD 1 A Hz
pulsating AC/DC-sensitive type A, for frequencies ≠ 50 Hz
Article No. 09340353

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AT
Function
MRCDs (modular residual current devices) consist of a combination of residual current transformer and evaluation unit. In connection
with a separate external circuit-breaker, they allow the implementation of protective measure "Automatic switch-o of power supply" as
per DIN VDE 0100-410 and IEC 60364-4-41. They are primarily useful when no RCCBs or CRBs can be used due to high load currents or
mains voltages. The MRCD detects the residual current and evaluates it in terms of its level and duration. If the residual response current
thresholds and the response time are exceeded, it activates a separate switch-o device that disconnects the system part for which it is
responsible from the power supply. Modular residual current circuit-breakers from series DMRCD have a number of usable total current
transformers and therefore also a number of conductor cross-sections or rated currents. They have one changeover contact and one LED
each for the pre-alarm and main alarm. The bar display provides a view of both the current residual current and the set value for the prealarm. The devices have two response thresholds. The response thresholds for the pre-alarm can be set from 10% to 90% of the response
threshold for the alarm. The set value for the pre-alarm threshold is displayed as a continuously lit LED on the bar display. The alarm is
triggered at a xed response threshold. The current level of the residual current, the response threshold of the pre-alarm 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 ashing 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. Modular protective
devices with residual current characteristic A detect sinusoidal AC currents as well as pulsating DC residual currents. The "Hz" variant is
suitable for monitoring circuits with frequencies from 50 Hz to 60 Hz (type A) and from 40 Hz to 2000 Hz (type AC). The residual response
current is xed at 2000 Hz.
Features
suitable for detecting type A residual currents, monitored frequency range type A 50-60 Hz, type AC 40-2000 Hz, rated residual operating
current 30 mA, large selection of dierent residual current transformers, rated currents up to 400 A, rated voltage of monitored circuit
up to 690 V, with alarm relay, one potential-free changeover contact, selectivity adjustable at ten levels, dependent on auxiliary voltage,
compact, robust plastic housing, easy mounting, complies with DIN EN 60947-2 / VDE 0660-101, VDE 0100-410 / IEC 670364-4-41 and
VDE 0100-530
Mounting
quick fastening to mounting rail, any installation position
Applications
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., especially suitable for use in welding machines, especially suitable for protection of
persons and preventative re control, 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 50 Hz.
Notes
Type A residual currents are detected separately by external residual current transformers from series DCT A, which are ordered
separately. No more than one transformer can be operated on one evaluation unit. The VDE certication is only fullled with approved
switch-disconnector combinations and undervoltage trips (see operating instructions). To meet DIN VDE 0100-410, the electrical system
must be isolated from the mains by an external isolating device with a response time of less than 15 ms. The maximum cable length from
the control relay to the transformer is 10 m. If residual currents with frequencies ≠ 50/60 Hz are expected (multiphase operated electronic
equipment such as frequency converters), correct display and indication of a 50/60 Hz residual current cannot be guaranteed. For these
applications we recommend our AC/DC sensitive residual current control relays from series DMRCD type B+.

2015_03_13

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