Indication of important instructions and information...............5 Signs and symbols............................5 Service and Support............................5 Training courses and seminars........................6 Delivery conditions............................6 Inspection, transport and storage......................6 Warranty and liability.............................6 Disposal of Bender devices..........................7 1.10 Safety..................................7 Safety instructions......................8 Product description......................9 Intended use..............................9 Area of application............................9 Device features..............................
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Table of contents Installation instructions for measuring current transformers............21 Commissioning........................23 Setting addresses............................23 Offset calibration............................24 Completing and checking installation....................25 Test, reset, function test....................26 Periodic self test............................26 Manual self test..............................26 7.2.1 Integrated "T" button..........................26 7.2.2 External test/reset button..........................26 Function test..............................
Protect from dust Temperature range Recycling RoHS directives Service and Support Information and contact details about customer service, repair service or field service for Bender devices are available on the following website: Fast assistance | Bender GmbH & Co. KG. MRCDB300-series_D00343_06_M_XXEN/07.2024...
Regular face-to-face or online seminars for customers and other interested parties: www.bender.de > know-how > seminars. Delivery conditions The conditions of sale and delivery set out by Bender GmbH & Co. KG apply. These can be obtained in printed or electronic format. The following applies to software products: "Software clause in respect of the licensing of standard software as part of deliveries,...
MRCDB300 series Disposal of Bender devices Abide by the national regulations and laws governing the disposal of this device. For more information on the disposal of Bender devices, refer to www.bender.de > service & support. 1.10 Safety If the device is used outside the Federal Republic of Germany, the applicable local standards and regulations must be complied with.
This manual is intended for qualified personnel working in electrical engineering and electronics! Part of the device documentation in addition to this manual is the enclosed supplement "Safety instructions for Bender products". DANGER Risk of fatal injury due to electric shock! Touching live parts of the system carries the risk of: •...
Product description Intended use The AC/DC sensitive residual current monitors of type MRCDB300 series are used in combination with a CTBC… measuring currentt transformer 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.
Product description Variants Electronic modules • MRCDB301 Type B modular residual current protective device acc. to IEC 60755 for the protection of persons in case of indirect contact, response value 30 mA • MRCDB302 Type B+ modular residual current protective device acc. to VDE 0664-100 for fire protection, response value 300 mA •...
MRCDB300 series page 24). After successful offset calibration, the multicolour LED lights up green and the device is ready for operation. Test Press the "T" button or the external test button for 5…10 s to start the manual self test of the device.
Mounting Mounting Only skilled persons are permitted to carry out the work necessary to install, put into service and run a device or system. DANGER Risk of fatal injury due to electric shock! Touching live parts of the system carries the risk of: •...
Mounting Mountings CTBC20(P) / CTBC35(P) CTBC60(P) CTBC120(P) / CTBC210(P) Type CTBC20(P) 31.4 2 x ø 5.5 CTBC35(P) 49.8 2 x ø 5.5 CTBC60(P) 2 x ø 6.5 CTBC120(P) 4 x ø 6.5 CTBC210(P) 4 x ø 6.5 all dimensions in mm, tolerance ±0.5 mm Assembly Slide the electronic module onto the plug contacts of the measuring current transformer.
MRCDB300 series Connection Connecting the device DANGER Risk of fatal injury due to electric shock! Touching live parts of the system carries the risk of: • Risk of electrocution due to electric shock • Damage to the electrical installation • Destruction of the device Before installing the device and before working on its connections, make sure that the installation has been de-energised.
Connection Wiring diagrams The following applies to all wiring diagrams: • The use of a type 2 surge protection device (SPD) is mandatory due to possible impulse voltages and in order to comply with normative requirements. • The surge protection device must be connected upstream of the power supply unit on the supply side. •...
Connection 5.3.2 N/C principle with contact feedback Wiring diagram MRCDB30… (N/C principle with contact feedback) 11, 12, 14 = 21, 22, 24 = Legend Relay for prewarning Relay for main alarm surge protection device The contact feedback ensures that the trip circuit is in the desired switching state. If due to events such as - burnt relay contacts (K2) on the MRCDB30…...
MRCDB300 series of state. A failure of the trip circuit, which would otherwise go undiscovered, is detected immediately. This information can be forwarded via the RS-485 interface or relay K1 to a control centre. 5.3.3 N/O principle without contact feedback Wiring diagram MRCDB30…...
MRCDB300 series We recommend operating the alarm relay K1 according to the N/C principle. This allows detecting and reporting the failure of the supply voltage and the internal power supply unit. For economical installation reasons, alarm relay K2 can be operated according to the N/O principle.
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Connection Live conductors Ensure that all live cables/conductors are routed through the measuring current transformer. Protective conductors Never route an existing protective conductor through the measuring current transformer. The cable diameter should not exceed half the diameter of the measuring current transformer. Bending of cables The cables/conductors should only be bent at a certain distance from the measuring current transformer.
MRCDB300 series Commissioning Setting addresses Every MRCDB300 series 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 If the preset address is to be changed, this can be done •...
The residual current monitoring module must be calibrated to the system to be monitored so that the selected protective function can be fulfilled. Each electronic module MRCDB300 series must be individually calibrated to the CTBC… built-in measuring current transformer. Calibration can be carried out by means of the "T"...
MRCDB300 series • A replacement of an MRCDB300 serieselectronic module • A 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.
Test, reset, function test Periodic self test The MRCDB300 series electronic module carries out a self diagnosis at regular intervals and thus ensures the device function. The electronic module feeds a test current into the test winding of the measuring current transformer.
MRCDB300 series Modbus register This chapter provides a complete description of the Modbus register for the MRCDB300/RCMB300 series to allow access to information. The following Modbus function codes are supported • Holding register for reading out values (Read Holding Register; function code 0x03) •...
Modbus register 8.1.4 Representation of values Value Description Value Description No test Hertz Test status Internal test Baud External test Farad No alarm Henry Prewarning Degree Celsius Error Degree Fahrenheit Alarm status Reserved Second Warning Minute Main alarm Hour Unit <...
String UTF-8 Serial number Example: yyyyyyyyy\0 Maximum 96 characters (\0 = 1098 String UTF-8 Manufacturer name end character) Bender GmbH & Co. KG\0 Character is in the LoByte 1194 UINT16 Application D-number Version number multiplied by 1195 UINT16 Application version Example: 123 = V1.23...
With the detailed measured values, status information and units etc. are also transmitted in addition to the measured values. This function is mainly required for the Bender COMTRAXX® system. However, it can also be of interest for direct readout of the Modbus registers, as these registers can be used to query the measured values and associated status information all at once and in direct succession.
MRCDB300 series Pro- Register Format Description Value/unit perty 4032 UINT16 Measuring channel number (3) 4033 Float32 Residual current measured value (RMS) 4035 UINT16 Test and alarm status 4036 UINT16 Range and unit 4037 UINT16 Description 4038…4047 Reserved 4048 UINT16 Measuring channel number (4)
Modbus register Pro- Register Format Description Value/unit/comment perty Measured value I (AC) 8000 Float32 Measured value I (DC) 8002 Float32 Measured value I (RMS) 8004 Float32 8006 Float32 Device error and status information Device/info code 8008 UINT32 Number of alarms Measured value I (AC unfiltered) 8010...
The device restarts completely (switching 6.00 Calibration error of relays possible). If the error persists, return the device or contact Bender service. No offset measurement No initial offset 6.10 Calibration error has been performed in the Perform offset measurement.
Modbus register Pro- Register Format Description Value/unit/comment perty 12000 UINT16 Event 1 measuring channel number 12001 UINT32 Event 1 start 12003 UINT32 Event 1 end 12005…12006 Reserved 12007 Float32 Event 1 min. value 12009 Float32 Event 1 max. value 12011 UINT16 Event 1 unit/test status HiByte: unit | LoByte: test status...
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MRCDB300 series Value range MRCDB Register Format Property Description Unit {Step size} Limit value 0.03… 3.00 A 16012 Float32 0.03 A 0.3 A 0.03 A 0.3 A 0.03 A main alarm {1 mA} Limit value 50…100 % 16014 Float32 60 %...
Modbus register Pro- Factory Register Format Description Value/unit/comment perty setting Flag to allow changing important registers. Is automatically Allow register write deactivated after five seconds. 20005 UINT16 access 1 = deny 2 = allow Makes the LED flash quickly red and green in alternation to detect the device in its environment faster.
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MRCDB300 series Sub-function code Sub-function code name Error counter Supported Notes number (decimal) Return Bus Message Count Return Bus Communication Error Count Return Bus Exception Error Count Return Server Message Count Return Server No Response Count Return Server NAK Count...
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Modbus register Device Identification (function code 0x2B) Object ID Object name / Description Data type Category Supported Notes 0x00 Manufacturer name Corresponds to register 1098 0x01 Article number Corresponds to register 1034 Basic Application software, version and Corresponds to registers 1194, 0x02 build number 1195 and 1196...
MRCDB300 series Technical data System states: LED and output relays slowly Error medium Mode change quickly Ready for address setting mode slowly flashing Address setting mode once Confirmation The LED indicates the system state by means of colours and lighting/flashing. The changeover contacts of relay outputs K1 and K2 have defined switching positions for each system state.
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Technical data Changeover contact System state Notes Alarm (green) (red) The reset status is achieved by pressing and holding the "T" button in the alarm Flashes Reset status. To perform the reset, release the slowly "T" button when the red LED flashes slowly (1.5...5 s).
Technical data Type B Fire protection 100 kHz Tabular data ( )* = factory setting MRCDB300-series_D00343_06_M_XXEN/07.2024...
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MRCDB300 series Insulation coordination acc. to IEC 60664-1/IEC 60664-3 Definitions Measuring circuit (IC1) Primary conductors routed through the current transformer Terminal block 1 Secondary (IC2) (24 V, GND, D1, DG, T/R, GND, A, B, X1, X2) Control circuit 1 (IC3)
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Technical data Supply voltage Supply voltage U DC 24 V Operating range of U ±20 % Ripple U ≤ 1 % Power consumption ≤ 2.5 W Inrush current 1.7 A for 1 ms Measuring circuit Internal diameter measuring current transformer see “Dimension diagrams”, page 13 Characteristics according to IEC 62020 and IEC/TR AC/DC sensitive, type B...
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MRCDB300 series Operating uncertainty ±17.5 % Relative uncertainty 0…–35 % Test winding Possible response values (to be set on the evaluator) CTBC20, CTBC20P 10…500 mA CTBC35, CTBC35P, CTUBC60, CTBC60P 30 mA…10 A CTBC120P, CTBC210P 100 mA…10 A CTBC120, CTBC210 300 mA…10 A...
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Technical data Outputs Number of changeover contacts Relay mode MRCDB301, MRCDB302, MRCDB305 N/C principle MRCDB303 N/C principle or N/O principle, (freely configurable), (N/C principle)* MRCDB304 N/O principle Switching outputs (K1, K2) 250 V, 5 A Switching capacity 1500 VA / 144 W Contact data acc.
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MRCDB300 series Connection Required terminals are included in the scope of delivery (except MRCDB304). Terminal block 1 Manufacturer Phoenix Contact Type DFMC 1,5/5-ST-3,5 BK The connection conditions of the manufacturer apply. Connection properties rigid 0.2…1.5 mm² (AWG 24…16) flexible 0.2…1.5 mm² (AWG 24…16) with ferrules 0.25…0.75 mm²...
≤ 620 g CTBC120 ≤ 1390 g CTBC120P ≤ 1750 g CTBC210 ≤ 4220 g CTBC210P ≤ 4870 g Standards and certifications Conformity EU Declaration of Conformity The EU Declaration of Conformity is available at the following Internet address: https://www.bender.de/fileadmin/content/Products/CE/CEKO_MRCDB30x.pdf MRCDB300-series_D00343_06_M_XXEN/07.2024...
MRCDB300 series Ordering details Electronic modules Supply voltage Variant Type Art.No. Protection of persons MRCDB301 B74043120 Fire protection MRCDB302 B74043121 Protection of persons, fire protection and plant MRCDB303 B74043122 DC 24 V protection (freely configurable) (19.2…28.8 V) Plant protection MRCDB304...
Technical data Suitable system components Max. number of Description Type Art. No. current transformers STEP-PS/1 AC/24 DC/1.75 B94053111 Voltage supply STEP-PS/1 AC/24 DC/4.2 B94053112 Document revision history Document Date Starte/Changes version Added 07.2021 Certifications Lloyds and UKCA Added Note acc. to standard DIN EN 45545-2 04.2024 Editorial revision Dimension diagrams, wiring diagrams, layout complete document...
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MRCDB300 series MRCDB300-series_D00343_06_M_XXEN/07.2024...
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