Neutral Grounding Resistor Monitor

_Efc BENDER Neutral Grounding Resistor Monitor Device features • Determination of Rngr with passive and active measurement methods • Continuous monitoring of the Rngr even if the installation is de-energized; • Alarm or trip on ground fault • Monitoring of the voltage UNGR • Faulted phase indication (optional; up to 690 V direct coupling, otherwise via potential transformers) • Ethernet communication • Language selection (German, English GB and US, Spanish, French) • Test button (internal, external) with/without tripping • FFT analysis of neutral current and voltage • Pulser control for manual...

Function The NGRM7… monitors NGR resistance RNGR, neutral voltage UNGR and current INGR. NGR resistance is monitored using an active and a passive procedure: active The device generates an active test pulse and measures RNGR even if the installation is de-energised. passive Only effective when installation is energized: The resistance RNGR is determined when INGR or UNGR exceeds an internal threshold. The device measures the existing current and voltage and calculates RNGR. In the case of the “auto” method, monitoring switches automatically between “active” and “passive” when the measured current...

NGR monitor NGRM Kr BENDER Display elements 4 - TRIPPED The LED is on when the trip relay has been tripped due to an NGR fault, ground fault or a device error. 5 - NGR FAULT The LED flashes in case of a prewarning: NGR fault detected, NGR-fault relay has tripped, trip relay has not tripped yet (fNGR trip elapses). The LED is on when an NGR fault has been detected. Trip relay and NGR-fault relay have tripped. 6 - GROUND The LED flashes in case of a prewarning: ground FAULT fault detected, ground-fault relay has tripped, trip relay has not tripped yet ((gf trip elapses). on when power supply is...

Connection star connection: Usys ≤ 690 V For these voltages, the phase monitor of the NGRM7… can be connected directly to the phase conductors to be monitored. Circuit breaker L1 Ground fault The “N” connection of the CD-series coupling device should be as close to the transformer star point as possible. Connection Star connection: Usys ≤ 690 V with pulser Circuit breaker L1 Ground fault X1 X1 Ethernet Pulser OUT RP = RPulser The “N” connection of the CD-series coupling device should be as close to the transformer star point as possible. An intermediate relay may be required between the power...

Connection star connection: Usys > 690 V For these voltages, the phase monitor of the NGRM7… can only be connected to the conductors to be monitored via potential transformers (PT). Circuit breaker Ground fault Note: * PT ratio "primary: secondary" can be adjusted in the NGRM7…. The “N” connection of the CD-series coupling device should be as close to the transformer star point as possible Artificial neutral (delta connection): Connection with a zigzag transformer If no star point is available, the following circuit can create an artificial neutral. Circuit breaker L1 L2 L3 Ground fault

Measuring current transformer connection Depending on the system to be monitored, a suitable measuring current transformer has to be chosen. All common measuring current transformers (50 mA or 5 A on the secondary side) can be used. The following table helps you with the choice: System type Transformation ratio Bender measuring current transformer Measuring range (see CTUB103 manual) 5 A 100:1 10 A 200:1 25 A 500:1 Connecting cable CTAC… / CTAS… Any standard current transformer can be used. Connection of relays (ground-fault, NGR and trip relay) Ground-fault relay NGR-fault relay Trip relay The...

NGR monitor NGRM Kr BENDER Switch open closed Digital 1, active Reset, passive Test _n_r Switch open closed Digita| 1,active Reset, passive Test Connection to Q1, Q2: external relay or PLC. £ Observe maximum current values! The maximum output current on X1(+24 V) is 100 mA. In case of higher currents, the relays require an external 24 V supply. The maximum current on Q1 and Q2 is 300 mA each. Input I1...3: Potential-free contact to common or Analogue output

Technical Data Insulation coordination according to IEC 60664-1/IEC 60664-3/DIN EN 50178 Monitoring RNGR Measuring input RS < 33 V RMS Measuring range NGR (with RS = 20 kΩ) active 0…10 kΩ Measurement uncertainty for T = 0…+40 °C ±20 Ω Measurement uncertainty for T = –40…+70 °C ±40 Ω Measuring range NGR (with RS = 100 kΩ) active 0…10 kΩ Measurement uncertainty for T = 0…+40 °C ±30 Ω Measurement uncertainty for T = –40…+70 °C ±80 Ω HRG Setting range RNGR nom15 Ω…5 kΩ Response value RNGR nom 110…200 % RNGR nom LRG Setting range RNGR nom0.1…200 Ω Response value >RNGR nom200…500 Ω Response delay,...

Digital inputs Galvanic separation Length connecting cables Uin Overload capacity Digital outputs Galvanic separation Length connecting cables Currents (sink) for each output Voltage Overload capacity Analogue output (M+) Operating principle linear Functions INGR, RNGR Current 0…20 mA (≤ 600 Ω), 4…20 mA (≤ 600 Ω), 0…400 μA (≤ 4 kΩ) Voltage 0…10 V (≥ 1 kΩ), 2…10 V (≥ 1 kΩ) Tolerance related to the current/voltage end value ±20 % Ground-fault, NGR, trip relay Switching elements Operating mode Electrical endurance, number of cycles Switching capacity Contact data acc. to IEC 60947-5-1 Rated operational...

RBENDER Ordering information 11 All types and ordering informations of this series are available on our website

RBENDER Bender GmbH & Co. KG • Germany Londorfer StraRe 65 • 35305 Grunberg Tel.: +49 6401 807-0 • [email protected] www.bender.de USA, Mexico, Central America • Exton PA, USA 800.356.4266 / 610.383.9200 • [email protected] www.bender.org Canada • Missisauga ON, Canada 800.243.2438 / 905.602.9990 [email protected] • www.bender-ca.com South America • Santiago de Chile © Bender GmbH & Co. KG, Germany Subject to change! The specified standards take into account the edition valid until 07.2023 unless otherwise indicated.