Description
ABB NVAR-45
Technical Specifications: Model: NVAR-45 Monitored supply: Three phase AC voltage Voltage monitoring range: Configurable according to rated specification Detection functions: Overvoltage, undervoltage, phase loss, phase unbalance, phase sequence Output type: Electromechanical relay contact output Power supply: Derived from monitored three-phase supply Operating temperature range: -20℃ ~ +60℃ Storage temperature range: -40℃ ~ +85℃ Relative humidity: 5% to 95%, non-condensing Mounting: DIN rail mounting Protection grade: IP20
Functional Features: Continuous real-time monitoring of three-phase AC line voltage. Detect overvoltage and undervoltage condition with adjustable threshold setting. Identify phase loss, phase unbalance and wrong phase sequence automatically. Adjustable time delay for fault detection to avoid false trip caused by transient voltage fluctuation. Relay contact output for alarm signal or equipment trip interlock. LED indicators for power supply status and fault alarm indication. No separate auxiliary power supply required, power taken from monitored three-phase lines. Robust circuit design for heavy industrial power distribution environment.
Application Scenarios: Motor control center cabinet, water pump motor protection, HVAC fan power supervision, conveyor drive power monitoring, frequency converter input voltage protection, industrial machine tool power supply monitoring, power distribution cabinet three-phase voltage supervision.
Performance Parameters: Fast detection response for permanent phase loss and severe voltage deviation. Adjustable time delay suppress transient voltage disturbance to prevent false alarm. Relay contact rated capacity for direct interlock and alarm circuit driving. Continuous operation: 24 hours stable monitoring inside low voltage power cabinet. High tolerance to normal minor voltage fluctuation of industrial power grid.
Material Composition: PCB substrate: FR4 glass fiber epoxy printed circuit board. Core components: Voltage sampling circuit, comparator IC, timing circuit, electromechanical relay. Housing: Black flame retardant PA plastic DIN rail enclosure. Terminal blocks: PA66 flame retardant plastic screw terminals with nickel plated copper contacts. Front cover: Transparent polycarbonate window for LED viewing.
Structural Features: Compact rectangular DIN rail housing structure. Front panel with transparent window, LED indicators and adjustment potentiometers for threshold and delay setting. Screw terminals arranged at bottom of housing for three-phase voltage input and relay output wiring. Rear side integrated DIN rail clip for fast installation and removal. Internal circuit separated into high voltage sampling area and low voltage logic control area.
Working Principle: Three-phase AC voltage is connected to module input terminals. Internal voltage sampling circuit reduces high line voltage to low level signal for logic circuit. Sampled voltage signal is compared with preset threshold value set by front panel potentiometers. When voltage exceeds overvoltage threshold, drops below undervoltage threshold, phase is missing, phase unbalance exceeds limit or phase sequence is reversed, timing circuit starts countdown according to set delay time. After delay period completes, relay coil is energized and relay contact changes state to send alarm or trip signal. LED indicator lights up to show fault type. When three-phase voltage returns to normal condition, relay resets automatically.
Installation Requirements: Mount NVAR-45 onto standard DIN rail inside low voltage electrical cabinet. Disconnect three-phase power supply before wiring. Connect three-phase monitored voltage lines to input terminals and connect relay contact wiring to alarm or interlock circuit. Adjust overvoltage, undervoltage threshold and fault delay time on front panel potentiometers. Ensure cabinet protective earth ground connection is reliable. Leave small clearance around module for heat dissipation. Use copper wires with proper cross section for power input wiring.
Usage Notes: Cut off three-phase supply before opening housing or modifying wiring. Do not exceed rated input voltage range of module. Check phase sequence setting before commissioning. Regularly inspect terminal screw tightness to avoid loose connection under vibration. Do not touch internal circuit after power is connected. Do not operate module outside rated temperature range. Keep housing cover closed during normal operation.
