{"product_id":"bender-ir420-d4-2-300v-insulation-monitor-for-ac-it-systems","title":"Bender VMD421H-D-3 500V 15-460Hz Voltage Monitoring Relay for 3AC Systems","description":"\u003cdiv\u003e\u003cspan\u003eThe VMD421H-D-3 is a multifunctional voltage monitoring relay from Bender, part of the LINETRAXX® series. It is designed for 3(N)AC systems to monitor undervoltage, overvoltage, underfrequency, overfrequency, asymmetry, phase failure, and phase sequence. The device uses true RMS measurement to ensure accuracy even in harmonic‑rich industrial environments.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eThe device requires no external auxiliary supply; its operating power is taken internally from the monitored nominal system voltage. An integrated backup power supply ensures that the device remains operational and event records are not lost even when the monitored voltage is interrupted.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eTechnical Specifications\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Rated system voltage (Uₙ): 3(N)AC 70…500 V (phase‑to‑phase) \/ 288 V (phase‑to‑neutral), 15…460 Hz\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Alarm relays: Two independent changeover contacts (K1, K2), AC 250 V \/ 6 A\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Monitoring functions: Undervoltage, overvoltage, underfrequency, overfrequency, asymmetry, phase failure, phase sequence, window discriminator function\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Measurement accuracy: Voltage (50\/60 Hz) ±1.5%, ±2 digits; frequency ±0.2%, ±1 digit\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Response time: Voltage ≤ 140 ms; frequency ≤ 335 ms\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Measuring range: Voltage 0…500 V (AC); frequency 10…500 Hz\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Display: Multi‑function LCD display showing real‑time measured values\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· LED indicators: Power On (green), Alarm 1 (yellow), Alarm 2 (yellow)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Power consumption: ≤ 6 VA\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Operating temperature: –25 °C … +55 °C\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Mounting: DIN rail (35 mm), width 36 mm (2 standard modules)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Protection class: Terminals IP20, internal components IP30\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Housing: Sealable transparent cover to prevent unauthorised parameter changes\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Standards compliance: IEC 61010‑1, IEC 60255‑6, IEC 60664‑1\/IEC 60664‑3\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Connection types: Push‑wire terminals (B73010007) or screw terminals (B93010007)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Order numbers: B73010007 (push‑wire), B93010007 (screw)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eKey Features\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· No external supply required – Operating power taken internally from the monitored nominal system voltage, simplifying installation\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Integrated backup power – Maintains operation and event records even during monitored voltage interruption\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· True RMS measurement – Accurate voltage monitoring even with harmonic distortion and non‑sinusoidal waveforms\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Multifunctional monitoring – Undervoltage, overvoltage, underfrequency, overfrequency, asymmetry, phase failure, phase sequence, window discriminator\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Two independent alarm relays – Configurable for different alarm conditions with selectable N.O.\/N.C. operation and optional fault memory\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Adjustable hysteresis – Prevents relay chatter due to voltage fluctuations\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Adjustable time delays – Start‑up delay, response delay, and release delay to prevent nuisance tripping\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Preset function – Automatically assigns basic parameters upon first connection, simplifying commissioning\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Event memory – Stores measured values at the time the alarm relay was activated for diagnostic purposes\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Continuous self‑monitoring – Internal self‑test ensures operational reliability\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Built‑in test\/reset button – Manual testing and reset without external controls\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eTypical Applications\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Monitoring of voltage‑sensitive equipment and electrical installations\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Emergency and standby generator monitoring – ensures voltage and frequency stability before load transfer\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Voltage monitoring for portable loads\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Three‑phase motor protection – prevents phase loss and phase faults\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Transformer protection – detects unbalanced loads\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Grid stability monitoring at the point of connection for renewable energy systems (solar, wind)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Power quality monitoring in data centres\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Power quality monitoring in medical locations (operating theatres, ICUs)\u003c\/span\u003e\u003c\/div\u003e","brand":"Bender","offers":[{"title":"Default Title","offer_id":44144494248024,"sku":null,"price":1195.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0580\/2799\/9320\/files\/VMD421H-D-3.jpg?v=1779794014","url":"https:\/\/gexufein.com\/products\/bender-ir420-d4-2-300v-insulation-monitor-for-ac-it-systems","provider":"Gexufein Automation","version":"1.0","type":"link"}