Bender MRCDB300 Series User manual

Quickstart guide ENMRCDB300-series_D00343_05_Q_XXEN/01.2022
MRCDB300 series
AC/DC sensitive residual current monitoring module
for MRCD applications

2 MRCDB300-series_D00343_05_Q_XXEN/01.2022
MRCDB300 series
i
Part of the device documentation in addition to this quick-start guide is the enclosed "Safety
instructions for Bender products" and the operating manual. This quick-start guide applies to the
following devices:
Type Supply voltage Intended purpose Order number
MRCDB301 DC 24 V (19.2…28.8 V) Protection of persons (30 mA) B74043120
MRCDB302 DC 24 V (19.2…28.8 V) Fire protection (300 mA) B74043121
MRCDB303 DC 24 V (19.2…28.8 V) Freely congurable (30 mA…3 A) B74043122
MRCDB304 DC 24 V (19.2…28.8 V) Plant protection (300 mA) On request
MRCDB305 DC 24 V (19.2…28.8 V) Protection of persons (30 mA) B74043125
Intended use
The AC/DC sensitive residual current monitors of type MRCDB30… are used in combination with
a CTBC… measuring 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. This quickstart guide
does not replace the operating manual of the device. Download: www.bender.de/manuals
Safety instruction
I Danger of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
- An electric shock
- Damage to the electrical installation
- Destruction of the device
Before installing and connecting the device, make sure that the installation has been de-ener-
gised. Observe the rules for working on electrical installations.
Dimension diagrams MRCDB30... + CTBC... (all dimensions in mm, tolerance ±0.5 mm)
c
b
de
aType 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
g
a
d
e
c
f
b

MRCDB300 series
MRCDB300-series_D00343_05_Q_XXEN/01.2022 3
Dimensions of mountings
a
b
c
a
b
c
a
b
c
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 6.5
CTBC20(P)/CTBC35(P) CTBC60(P) CTBC120(P)/CTBC210(P)
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.
Device view
21 22 2411 12 14
K1 K2
34789
125610
11 12
11 12
13 14
No. Terminal Meaning
124 V Supply voltage US
2GND
3D1 Contact feedback
4DG
5T/R Connection external test/reset
6GND
7ARS-485 interface
8B
9X1 Terminals for cable bridge for connection of the
integrated 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"
Slide the electronic module onto the
plug contacts of the measuring current
transformer.
2
1
i
Avoid repeated plugging
and unplugging of the elec-
tronics (10 plugging cycles).

4 MRCDB300-series_D00343_05_Q_XXEN/01.2022
MRCDB300 series
Connection - N/C principle with contact feedback
Refer to the manual for further connection options.
Commissioning - Modbus RTU
Address setting
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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 de-
vice.
The address can be changed on the device before installation and offset calibration. The electron-
ic module must not be connected to the measuring current transformer during address setting.
Each address in the bus system may only be assigned once.
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The use of a type 2 surge protection de-
vice (SPD) is mandatory due to possible
impulse voltages and in order to comply
with normative requirements.
The surge protection device must be con-
nected 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
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 con-
nected by means of a wire jumper or a
DIP switch.
X1 X2
120 Ω 120 Ω
DIP switch
COM465IP
last device
MRCDB30...
first device
Wire jumper

MRCDB300 series
MRCDB300-series_D00343_05_Q_XXEN/01.2022 5
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 relay 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 o o o Device is de-energised, no monitoring, no moni-
toring function. de-energised de-energised
Normal operating state lights o
The device is supplied with the specied voltage
and monitors the primary circuit. No residual
current ows which would lead to tripping.
energised energised
Prewarning lights ashes
briey
The device is supplied with the specied
voltage and monitors the primary circuit. A fault
current ows which exceeds the set limit of the
prewarning.
de-energised energised
Alarm state o lights
The device is supplied with the specied voltage
and monitors the primary circuit. A fault current
ows which exceeds the set limit of the alarm.
de-energised de-energised
Device error o ashes
slowly
The device is supplied with the specied 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 ash quickly in
alternation
Modbus register 20006 = 2
Use to detect the device in its environment faster.
Is automatically deactivated after one minute.
Reset o ashes
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 ashes
slowly (1,5…5 s).
Test ashes
quickly o
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
ashes quickly (5…10 s).
switches switches
A
B
C
D
E

6 MRCDB300-series_D00343_05_Q_XXEN/01.2022
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 in-
dividually calibrated to the built-in CTBC… measuring current transformer. Calibration can be car-
ried out by means of the "T" button or via the Modbus interface. A calibration must always per-
formed 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.
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The alarm relays switch to safe state during offset calibration (system is switched off).
Procedure of the first offset calibration
Action LED
1 Install the measuring current transformer in the system o
2Plug the electronic module and the measuring current transformer
together lights red
3 Disconnect the electronic module from the supply voltage o
4a Press and hold the "T" button o
4b Press and hold the "T" button, supply the electronic module with
supply voltage US
lights red permanently (not ready for operation)
ashes red slowly (A) (ready for calibration)
ashes red quickly (B) (calibration mode)
5 Start calibration: release "T"
6 Calibration in progress ashes red quickly (B)
7 Calibration successful, values are accepted, relay switches lights green permanently
8 Calibration nished, 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 pro-
tective conductors and low-resistance conductor loops through the measuring current trans-
former!
I Caution! Device damage due to interference pulses! The connecting cable (supply, analogue
interface…) must not be routed directly past the current transformer core.

MRCDB300 series
MRCDB300-series_D00343_05_Q_XXEN/01.2022 7
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.
i
Do not route any shielded cables through the measuring current transformer.
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Application in railway vehicles / DIN EN 45545-2:2016!
If the horizontal or vertical distance to adjacent components which do not meet the require-
ments 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.
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.
All current-carrying cables must be routed through the mea-
suring 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.

Alle Rechte vorbehalten.
Nachdruck und Vervielfältigung
nur mit Genehmigung des Herausgebers.
Bender GmbH & Co. KG
Postfach 1161 • 35301 Grünberg • Deutschland
Londorfer Str. 65 • 35305 Grünberg • Deutschland
Tel.: [phone] • Fax: [phone]
E-Mail: [email protected] • www.bender.de
All rights reserved.
Reprinting and duplicating
only with permission of the publisher.
Bender GmbH & Co. KG
PO Box 1161 • 35301 Grünberg • Germany
Londorfer Str. 65 • 35305 Grünberg • Germany
Tel.: [phone] • Fax: [phone]
E-mail: [email protected] • www.bender.de
MRCDB300-series_D00343_05_Q_XXEN/01.2022/ pdf / © Bender GmbH & Co. KG, Germany – Subject to change! The specied standards take into account the edition valid until 02/2022 unless otherwise indicated.
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
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