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Brand: Bender
Bender VMD460-NA-D-2 Network and System Protection Relay
Description
Grid-parallel protection for generating plants
The Bender VMD460-NA-D-2 is a network and system protection relay (NS protection) for monitoring the network feed-in of generating plants. It protects the public network and the generating plant from inadmissible operating states and disconnects them, and it permits (re)connection only when the switch-on conditions are met. The datasheet says the device is designed according to single-fault tolerance principles, and the country-specific application standards and guidelines are stored in the device as selectable basic programs. Examples listed are central NS protection to VDE-AR-N 4105, protective disconnection to VDE-AR-N 4110 and BDEW, interface protection to the UK Engineering Recommendations (EREC G99, G59, G83) and protezione di interfaccia to CEI 0-21.
The VMD460-NA-D-2 is the 100 to 240 V AC/DC supply version with article number B93010045. It monitors 1AC, 3AC and 3NAC systems and continuously evaluates the phase and line-to-line voltages and the frequency.
Technical specification
| Parameter | Specification |
|---|---|
| Type / article number | VMD460-NA-D-2, B93010045 |
| Supply voltage Us | AC/DC 100 to 240 V; operating range 75 to 300 V (DC and 40 to 70 Hz); power consumption below 7.5 VA / 3.5 W at 230 V (max. 9 VA); bridging time 600 ms at 230 V and dip to 0 V |
| Monitored systems | 1AC 230 V 50 Hz and 3(N)AC 400/230 V 50 Hz; nominal voltage L-N 0 to 300 V, L-L 0 to 520 V; frequency 45 to 65 Hz |
| Protection functions | U>, U>> (rise in voltage), U<, U<< (under-voltage), f>, f>>, f<, f<<, df/dt (ROCOF), vector shift, unbalance detection |
| Voltage accuracy | U up to 280 V: plus/minus 1 %; above 280 V: plus/minus 3 %; setting resolution 1 % |
| Frequency accuracy / resolution | Plus/minus 0.1 %; setting resolution 0.05 Hz; f< and f<< settings 45 to 60 Hz; f> and f>> 50 to 65 Hz; df/dt 0.05 to 9.9 Hz/s |
| Time response | Reconnection delay 40 ms to 60 min; operating time voltage half a supply period; operating time frequency max. 40 ms; recovery time 300 ms |
| Reconnection and monitoring | Reconnection after short interruptions; monitoring of tripping circuits and interface switches via contact feedback; remote trip via ripple-control receiver; test function for the trip circuit |
| Digital inputs | D1, D2 feedback of contacts K1 and K2; D3 local control; D4 external signal; RT1 remote trip; low 0 to 4 V, high 6 to 30 V; cable length max. 3 m |
| Outputs | 2 changeover contacts K1, K2, N/C or N/O operation; 10 000 cycles; AC-13 230 V 4 A (UL/CSA) / 5 A, AC-14 3 A, DC-12 24 V 1 A, 110 V 0.2 A, 220 V 0.1 A |
| Display and memory | Illuminated multi-functional LC display, 0 to 520 V; history memory of last 300 messages with one measured-value record each; password off/on 0 to 999 |
| Insulation coordination | Rated voltage 400 V; rated impulse voltage 6 kV, overvoltage category III; pollution degree 2; voltage test 3.32 kV |
| Environment | Operating temperature -25 C to +55 C; climatic class 3K23; mechanical class 3M11; EMC per DIN EN 60255-26 / CEI 0-21 |
| Connection | Screw-type or push-wire terminals; rigid 0.2 to 4 mm2, flexible 0.2 to 2.5 mm2; 0.5 to 0.6 Nm; stripping 8 to 9 mm |
| Enclosure | Polycarbonate UL 94 V-0; IP30 / IP20 terminals; DIN rail IEC 60715 or 2 x M4 screws; weight max. 360 g |
Islanding detection and reconnection
When a generating plant keeps feeding a part of the grid after the main supply has failed, the plant forms an unintended island. The VMD460-NA detects this through two methods named in the datasheet: df/dt (rate of change of frequency, ROCOF) and vector shift detection. It also trips on over and under voltage and frequency with two stages each, and on unbalance. Disconnection occurs when at least one activated protective function triggers; reconnection is released only after the configured delay once voltage and frequency are back inside their windows. The feedback contacts of the interface switches allow it to monitor that its own trip commands are executed.
Selection and configuration notes
- Select the basic program for the country or guideline of the installation; settings are stored in the device and shown on the display.
- Wire the feedback contacts of both interface switches to D1 and D2 to enable the tripping-circuit monitoring.
- Use the RT1 input for a remote trip signal from a ripple-control receiver where the network operator requires it.
- The 100 to 240 V supply allows operation from the monitored network or an auxiliary supply; the 600 ms bridging time covers short dips.
- Connection of inputs must not exceed 3 m.
GCC context
Solar plants and captive generators are being connected in parallel with utility networks in the Gulf. National utility rules differ and are not stated in the Bender datasheet, so the applicable grid code must be confirmed with the network operator before selecting a basic program. See the relays category for other Bender monitoring relays on this site.
Selection and installation notes
Insulation and residual current monitoring devices are selected from the system type (IT, TN or TT), the system voltage, the leakage capacitance and the alarm levels needed. Connect the device to the system and to earth as the manual shows, set the response values from the system design, check the coupling or measuring current transformer and its wiring, and test the alarm and relay outputs after commissioning. Do not do an insulation test of the plant with the monitor connected unless the manual allows it.
Information needed for a quotation
Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.
Documents and supply information
The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.
Frequently asked questions
What is the VMD460-NA used for?
As network and system (NS) protection for generating plants: it disconnects the plant on abnormal voltage or frequency, detects islanding and controls reconnection.
Which grid guidelines does it support?
The datasheet lists VDE-AR-N 4105, VDE-AR-N 4110, BDEW, the UK EREC G99, G59 and G83, and CEI 0-21 as selectable basic programs.
What is the supply voltage of the -D-2 version?
AC/DC 100 to 240 V, with an operating range of 75 to 300 V.
Does it detect islanding?
Yes, through df/dt (ROCOF) and vector shift detection.
Is Seven Star LLC the manufacturer?
No. Seven Star LLC is an independent supplier in Muscat; confirm the grid code with the utility before ordering.
Datasheets & Documents
- Datasheet Bender VMD460 datasheet (06.2021) Download
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About brand
Bender is a German family company specialising in electrical safety monitoring, based in Grünberg, Hesse. Walther Bender patented the insulation monitoring device he called the ISOMETER in 1942 and registered the company in Grünberg in 1946. Bender employs about 1,100 people across subsidiaries on four continents.
Seven Star LLC is an independent supplier in Muscat. We list Bender monitoring devices for power, oil and gas, marine, hospital and industrial installations in Oman and the GCC.
Bender company profile
| Founded | 1946, Grünberg, Germany |
|---|---|
| Founder | Walther Bender |
| Ownership | Bender family |
| Key invention | ISOMETER insulation monitor, patented 1942 |
| Product families | ISOMETER insulation monitors such as iso685 and IR425, EDS insulation fault locators, RCMS residual current monitors, NGRM neutral grounding resistor monitors |
Milestones
- 1942: The ISOMETER is patented.
- 1946: The company is registered in Grünberg.
- 2021: Bender marks 75 years.
Bender product series
Insulation monitors include the IR425-D4-2 for systems up to 300 V, the iso685-D-P for 690 V AC systems, the isoUG425-D4-4 earth fault monitor for 12-120 V DC and the IRDH275BM-7 for medium voltage networks. The EDS440-L-4 ISOSCAN locates the faulty feeder once an insulation fault is detected.
Residual current monitors include the RCMS460-D-2 twelve-channel monitor and the RCMA420-D-2 AC/DC monitor for 10 to 500 mA. The NGRM700 supervises neutral grounding resistors, the VMD460-NA-D-2 is a network and system protection relay, and the MK2430-11 COMTRAXX is a remote alarm indicator with twelve inputs.
Where Bender devices are used
IT power systems in plants, ships, hospitals and data centres, DC supplies and battery systems, generator and solar connections to the grid, and earthing systems with neutral grounding resistors.
Bender products we list
Ordering Bender devices: what we need
Send the Bender type and article number, system type (IT, TN or TT), nominal voltage and frequency, the supply voltage of the device and the alarm and communication outputs needed.
Facts checked against Bender's own history and 75th anniversary release, October 2026.
Browse Bender products by category: Switchgear, Enclosures & Distribution.
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Frequently Asked Questions
What is the VMD460-NA used for?
As network and system (NS) protection for generating plants: it disconnects the plant on abnormal voltage or frequency, detects islanding and controls reconnection.
Which grid guidelines does it support?
The datasheet lists VDE-AR-N 4105, VDE-AR-N 4110, BDEW, the UK EREC G99, G59 and G83, and CEI 0-21 as selectable basic programs.
What is the supply voltage of the -D-2 version?
AC/DC 100 to 240 V, with an operating range of 75 to 300 V.
Does it detect islanding?
Yes, through df/dt (ROCOF) and vector shift detection.
Is Seven Star LLC the manufacturer?
No. Seven Star LLC is an independent supplier in Muscat; confirm the grid code with the utility before ordering.
Reviews
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