Bender MRCDB300 Series User manual

MRCDB300-series_D00343_06_Q_XXEN/01.2024
MRCDB300 series
AC/DC sensitive residual current monitoring module
for MRCD applications
Quick-start guide EN

2 MRCDB300-series_D00343_06_Q_XXEN/01.2024
MRCDB300 series
c
b
de
a
Type a b c d e f g
MRCDB30…-CTBC20(P) 81 112 37 ø 20 46 60
MRCDB30…-CTBC35(P) 97 130 47 ø 35 46 61
MRCDB30…-CTBC60(P) 126 158 57 ø 60 56 78
MRCDB30…-CTBC120(P) 188 232 96 ø 120 65 96 139
MRCDB30…-CTBC210(P) 302 346 153 ø 210 67 113 277
MRCDB30… 74 37 44 2 4,6
MRCDB30…
MRCDB30... + CTBC20(P)/CTBC35(P) MRCDB30... + CTBC60(P) MRCDB30... + CTBC120(P)/CTBC210(P)
d
b
f
c
a e
d
e
f
c
b
a
k
d
a
b
e
f
c
MRCDB300 series
AC/DC sensitive residual current monitoring module for MRCD applications
This quick-start guide does not replace the manual!
Quick-start guide for the following devices
Type Supply voltage Intended purpose Art. No. Manual No.
MRCDB301 DC 24 V (19,2…28,8 V) Protection of persons (30 mA) B74043120 D00343
MRCDB302 DC 24 V (19,2…28,8 V) Fire protection (300 mA) B74043121 D00343
MRCDB303 DC 24 V (19,2…28,8 V) Freely configurable (30 mA…3 A) B74043122 D00343
MRCDB304 DC 24 V (19,2…28,8 V) Plant protection (300 mA) On request D00343
MRCDB305 DC 24 V (19,2…28,8 V) Protection of persons (30 mA) B74043125 D00343
Scope of delivery
• MRCDB30x
• Measuring current transformer core CTBCxx
• Safety instructions
• Quickstart DE/EN
Intended use
The AC/DC sensitive residual current monitors of type MRCDB30… are used in combination with a CTBC… meas-
uring current transformer core and a circuit breaker according to IEC 60947-2 as additional protection in industrial
power supplies. According to IEC 60364-5-53, the use in earthed power supplies (TN and TT systems) up to 800 V is
possible. These devices are suitable for monitoring AC and DC fault currents (type B).
Any other use than that described in this document is regarded as improper.
Dimension diagrams MRCDB30... + CTBC... (all dimensions in mm, tolerance ±0.5 mm)
Manaual

MRCDB300-series_D00343_06_Q_XXEN/01.2024 3
MRCDB300 series
Slide the electronic module onto the plug contacts of
the measuring current transformer.
i
Avoid repeated plugging and unplugging of the
electronics (10 plugging cycles).
2
1
Dimensions of mountings
Assembly
A complete residual current monitoring module consists of the MRCDB30x evaluation electronics and a
CTBC20(P)…210(P) series measuring current transformer core. If ordered separately, these two components must
be plugged together and calibrated during commissioning.
CTBC20(P)/CTBC35(P) CTBC60(P) CTBC120(P)/CTBC210(P)
Type a b c
CTBC20(P) 31,4 49 2 x ø 5,5
CTBC35(P) 49,8 49 2 x ø 5,5
CTBC60(P) 56 66 2 x ø 6,5
CTBC120(P) 103 81 4 x ø 6,5
CTBC210(P) 180 98 4 x ø 5,5
a
b
c
a
b
c
a
b
c
Device view MRCDB30…
21 22 2411 12 14
K1 K2
12345
10 9876
11 12
11 12
13 14
No. Terminal Meaning
124 V Supply voltage US
2 GND
3 D1 Contact feedback
4 DG
5 T/R
Connection external test/reset
6 GND
7 A RS-485 interface
8 B
9 X1 Terminals for cable bridge for connection of the inte-
grated terminating resistor of the RS-485 interface
10 X2
11 11, 12, 14 Relay K1 (prewarning)
12 21, 22, 24 Relay K2 (alarm)
13 – LED: operation“ON”and“Alarm”
14 – Test and reset button“T”

4 MRCDB300-series_D00343_06_Q_XXEN/01.2024
MRCDB300 series
Connection - N/C principle with contact feedback
Refer to the manual for further connection options.
Commissioning - Modbus RTU
i
Within an interconnection of devices via the RS-
485 interface, the first and the last device must
each be provided with a terminating resistor.
This device-internal resistor can be connected by
means of a wire jumper or a DIP switch.
X1 X2
120 Ω 120 Ω
Wire jumper
DIP switch
COM465IP
last device
MRCDB30…
first device
Address setting
i
Every MRCDB3… has a factory-set Modbus address. The address is 1XX, where XX = the last two digits of the
serial number. Example: Serial number = 12345678 -> Modbus address = 178
The preset address can be changed via a COMTRAXX gateway, via Modbus or directly on the device.
The address can be changed on the device before installation and offset calibration. The electronic module must
not be connected to the measuring current transformer during address setting. Each address in the bus system
may only be assigned once.
i
The use of a type 2 surge protection device (SPD)
is mandatory due to possible impulse voltages
and in order to comply with normative require-
ments.
The surge protection device must be connected
upstream of the power supply unit on the supply
side.
Features of the surge protection device:
– Nominal discharge current In(8/20 μs): 20 kA
– Response time: 25 ns
– Two-stage: 1 varistor + 1 spark gab
– Alternatively, the power supply unit must
be connected to a CAT II supply without a
surge protection device.
U<
F 6 A
L1
L2
L3
N
DC 24 V
AC
DC
21
GND
T/R
GND
24 V
22 24
21
22 24
11
12 14
3
MRCDB30...-CTBC...
DG
D1
i
For UL applications:
Only use 65/75 °C copper lines!
*

MRCDB300-series_D00343_06_Q_XXEN/01.2024 5
MRCDB300 series
LED flashing modes
slowly error
medium mode change
quickly ready for address modification
slow flashing address setting mode
once confirmation
System state LED and output relays
The LED indicates the system state by means of colours and lighting/flashing. The changeover contacts of the re-
lay outputs K1 and K2 have defined switching positions for each system state.
System state
GREEN
LED
ON
RED LED
Alarm Notes Relay K1 Relay K2
Device switched off off off Device is de-energised, no monitoring, no monitoring
function. de-energised de-energised
Normal operating state lights off
The device is supplied with the specified voltage and
monitors the primary circuit. No residual current flows
which would lead to tripping.
energised energised
Prewarning lights flashes
briefly
The device is supplied with the specified voltage and
monitors the primary circuit. A fault current flows which
exceeds the set limit of the prewarning.
de-energised energised
Alarm state off lights
The device is supplied with the specified voltage and
monitors the primary circuit. A fault current flows which
exceeds the set limit of the alarm.
de-energised de-energised
Device error off flashes
slowly
The device is supplied with the specified voltage and
monitors the primary circuit. An error is detected by the
periodic self tests.
de-energised de-energised
Device in calibration mode see manual for DC calibration procedure de-energised de-energised
Device in address mode see manual for procedure
Device signalling flash quickly in
alternation
Modbus register 20006 = 2
Use to detect the device in its environment faster.Is
automatically deactivated after one minute.
Reset off flashes
slowly
State is reached by pressing and holding the“T”button
during alarm state.To perform the reset, release the“T”
button when the red LED flashes slowly (1,5…5 s).
Test flashes
quickly off
State is reached by pressing and holding the“T”button
in normal operating state. To perform the test, release
the“T”button when the green LED flashes quickly
(5…10 s).
switches switches
A
B
C
D
E

6 MRCDB300-series_D00343_06_Q_XXEN/01.2024
MRCDB300 series
Offset calibration
The residual current monitoring module must be calibrated to the system to be monitored so that the selected
protective function can be fulfilled. Each MRCDB30… electronic module must be individually calibrated to the
built-in CTBC… measuring current transformer. Calibration can be carried out by means of the “T” button or via
the Modbus interface. A calibration must always performed in case of:
• New installation
• Replacement of a CTBC… measuring current transformer
• Replacement of an MRCDB30… electronic module
• Modification of the response value
In case of response values > 300 mA, no offset calibration is required.
If the device is not calibrated, the LED lights red permanently, commissioning is not possible. Note that during the
offset calibration the system is switched off and no current flows through the measuring current transformer.
If a current flows through the measuring current transformer despite the system being switched off, this indicates
a device error. Replace the measuring current transformer immediately.
i
The alarm relays switch to safe state during offset calibration (system is switched off).
Procedure of the first offset calibration
Action LED
1Install the measuring current transformer in the system off
2Plug the electronic module and the measuring current transformer together lights red
3Disconnect the electronic module from the supply voltage off
4a Press and hold the“T”button off
4b Press and hold the“T”button, supply the electronic module with supply
voltage US
lights red permanently (not ready for operation)
flashes red slowly (A) (ready for calibration)
flashes red quickly (B) (calibration mode)
5Start calibration: release“T”
6Calibration in progress flashes red quickly (B)
7Calibration successful, values are accepted, relay switches lights green permanently
8Calibration finished, normal operating status lights green permanently
Installation instructions measuring current transformer
I Caution! Device damage due to high induction currents! High currents can be induced into the conductor
loop due to the AC/DC sensitive measuring technology used. Do not route protective conductors and low-resist-
ance conductor loops through the measuring current transformer!
I Caution! Device damage due to interference pulses! The connecting cable (supply, analogue interface…)
must not be routed directly past the current transformer core.
I Caution! Risk of injury due to accessible live conductors!
The measuring current transformer must be connected to the corresponding evaluator before the first use and
before commissioning of the monitored system.

MRCDB300-series_D00343_06_Q_XXEN/01.2024 7
MRCDB300 series
i
Application in railway vehicles / DIN EN 45545-2:2016!
If the horizontal or vertical distance to adjacent components which do not meet the requirements in table 2 of
DIN EN 45545-2 is less than 20 mm or less than 200 mm respectively, they are to be regarded as grouped. Refer
to DIN EN 5545-2 chapter 4.3 Grouping rules.
i
Do not route any shielded cables through the measuring current transformer.
PE
L1
L2
L3
N
P1 (K): YE P2 (L): GY
Never route an existing protective conductor through the
measuring current transformer.
The primary conductors should only be bent from the specified minimum
distance.The minimum bending radius specified by the manufacturers for
the conductors used must be observed.
* Distance to 90° angle = 2 x outer diameter.
**
The cables must be aligned with the centre of the measuring
current transformer.
All current-carrying cables must be routed through the measuring current
transformer.
Completing and checking installation
The installation must be completed with a functional test: Press the “T” button for 5…10 s.
The system operator is obliged to have the MRCD protective devices checked at regular intervals by an electrically
skilled person to ensure that they are functioning properly. This requirement is deemed to be satisfied for normal
and environmental conditions if the test intervals mentioned in DGUV V3 (German Social Accident Insurance
Regulation 3) are adhered to. The test intervals are to be interpreted in accordance with the risk assessment.
The recurrent tests must include at least the following:
• Testing the environmental conditions for pollution, mechanical damage or insulation damage.
• To trip the circuit breaker, the integrated or the external test button is to be pressed.
Technical data
Rated voltage ...................................................................................... 800 V
Overvoltage category................................................................................. III
Nominal supply voltage Us.................................................................DC 24 V
Operating range Us..............................................................................±20 %
Power consumption..........................................................................≤ 2.5 W
Measuring circuit
Characteristics acc. to IEC/TR 60755 ..........................AC/DC sensitive, type B
Response values IΔn ...............................refer to intended purpose on page 2
Prewarning.......................................................................50 %…100 % IΔn
Rated current In
CTBC20 when IΔn ≥ 30 mA...............................................................40 A
CTBC20 when IΔn ≥ 300 mA............................................................. 63 A
CTBC20P ..........................................................................................80 A
CTBC35 when IΔn ≥ 30 mA...............................................................80 A
CTBC35 when IΔn ≥ 300 mA........................................................... 125 A
CTBC35P ........................................................................................160 A
CTBC60 when IΔn ≥ 30 mA............................................................. 160 A
CTBC60 when IΔn ≥ 300 mA........................................................... 250 A
CTBC60P ....................................................................................320 A

Bender GmbH & Co. KG
Londorfer Straße 65
35305 Grünberg
Germany
Tel.: [phone]
[e-mail]
www.bender.de
© Bender GmbH & Co. KG, Germany
Subject to change! The specified
standards take into account the edition
valid until 01/2024 unless otherwise
indicated.
Alle Rechte vorbehalten.
Nachdruck und Vervielfältigung nur mit
Genehmigung des Herausgebers.
All rights reserved.
Reprinting and duplicating only with
permission of the publisher.
EU Declaration of Conformity
The full text of the EU Declaration of
Conformity is available via the QR Code:
CTBC120 when IΔn ≥ 100 mA.....................................................330 A
CTBC120P when IΔn ≥ 100 mA...................................................630 A
CTBC210 when IΔn ≥ 300 mA.....................................................630 A
CTBC210P when IΔn ≥ 100 mA...................................................630 A
CTBC210P when IΔn ≥ 300 mA.................................................1000 A
Measurement accuracy........................................±1 % of full scale value
Test winding........................................................................................ yes
Rated continuous thermal current Icth.................................................30 A
Rated short-time thermal current 1) Ith.......................................2.4 kA/1 s
Rated dynamic current 1) Idyn....................................................6 kA/40 ms
1) refers to the residual current
Operating uncertainty ................................................................ ±17.5 %
Relative uncertainty .................................................................0…-35 %
Outputs
Outputs.................................................................. 2 changeover contacts
Operating principle............................................configurable, see manual
Switching outputs (K1, K2) .......................................................250 V, 5 A
Switching capacity............................................................1500 VA/144 W
Contact data acc. to IEC 60947-5-1
Rated operational voltage AC........................................ 250 V/250 V
Utilisation category .......................................................AC-13/AC-14
Rated operational current AC .................................................5 A/3 A
Rated operational voltage DC...................................... 220/110/24 V
Utilisation category ................................................................... DC12
Rated operational current DC...........................................0.1/0.2/1 A
Minimum current ..................................................... 10 mA at DC 5 V
Ordering details
Suitable measuring current transformer cores
ø current
transformers Type Art. No.
20 mm CTBC20 B98120001
CTBC20P B98120002
35 mm CTBC35 B98120003
CTBC35P B98120004
60 mm CTBC60 B98120005
CTBC60P B98120006
120 mm CTBC120 B98120007
CTBC120P B98120020
210 mm CTBC210 B98120008
CTBC210P B98120021
System components
max. connected
current transformers Type Art. No.
14 STEP-PS/1 AC/24 DC/1.75 B94053111
34 STEP-PS/1 AC/24 DC/4.2 B94053112
Accessories
Type Art. No.
USB to RS-485 interface converter B95012045
Terminal set for RCMB module (spare part) B74043124