Grounding Resistance Monitor (Indoor) - grounding monitoring
Precision Three-Wire Method + Local LCD Display, 35mm DIN Rail Indoor Grounding Grid Monitor
Suitable for online monitoring of lightning protection grounding grids. Uses precision three-wire method to measure grounding resistance and ground voltage in real time. Data can be uploaded to the cloud platform via RS485 (Modbus) and integrated into lightning protection systems. Supports local LCD display and button operation, easy installation, suitable for indoor environments such as distribution rooms.
Product Overview
The Indoor Grounding Resistance Monitor is an indoor screw/DIN-rail mounted grounding resistance monitoring device suitable for online monitoring of lightning protection grounding grids. It uses the precision 3-wire method to measure grounding resistance and ground voltage in Real-Time, and data can be uploaded to the cloud platform via RS485 (Modbus), integrating with the lightning protection system.
The device supports local LCD display and button operation, with easy installation suitable for distribution rooms and other indoor environments. It automatically performs a measurement every minute, reflecting grounding grid health status in Real-Time without manual intervention.
Core Capabilities
- Precision three-wire measurement, resistance 0.01Ω~2000Ω, voltage 0.1V~600V.
- Auto measurement every minute, real-time dynamically reflects grounding grid health status.
- Standard Modbus, supports bus networking, remote cloud monitoring via gateway.
- LCD + multi-button interaction, supports line resistance clearing, ID setting, test start/stop and other field operations.
Product Features
Precision 3-Wire Measurement
Resistance 0.01Ω~2000Ω, voltage 0.1V~600V, captures minor changes clearly, grounding resistance accuracy ±2%rdg±3dgt.
Wide Range, High Resolution
Standard Modbus, supports bus networking, remote cloud monitoring via gateway, grounding grid health at a glance.
RS485 Remote Transmission
Auto executes one measurement every minute, real-time dynamically reflects grounding grid health status, no manual intervention needed, data remote transmission to Cloud Platform.
Smart Self-Test
Auto executes one measurement every minute, real-time dynamically reflects grounding grid health status, no manual intervention needed, ensuring data continuous update.
Convenient Local Control
LCD with multi-button interaction, supports line resistance clearing, ID setting, test start/stop and other field operations, configuration without external devices.
DIN Rail Quick Mount
35mm standard DIN rail clip-on mounting, compact size (62×117×88mm), suitable for dense deployment in indoor distribution cabinets.
Selection Guide
Model Naming Rules
| Model | Mounting Location | Measurement Method | Acquisition Points | Dimensions (mm) | Mounting | Communication | ZIGBEE | Ethernet | 4G |
|---|---|---|---|---|---|---|---|---|---|
| FR-12021-R | Indoor | 3-point method | Resistance + Ground voltage | 62*117*88 | IndoorDIN Rail | RS485 | Yes | --- | --- |
| FR-12021-E | Indoor | 3-point method | Resistance + Ground voltage | 62*117*88 | IndoorDIN Rail | Ethernet | --- | Yes | --- |
| FR-12021-Z | Indoor | 3-point method | Resistance + Ground voltage | 62*117*88 | IndoorDIN Rail | Zigbee | Yes | --- | --- |
| FR-12031-R | Indoor | 3-point method | Resistance + Ground voltage | 62*117*88 | Indoorscrew | RS485 | Yes | --- | --- |
Technical Parameters
Basic Parameters
| Operating Voltage | 12V±1VDC,150mA Max |
| Power Consumption | 2W |
| Operating Temperature | -10℃~40℃ |
| Operating Humidity | <95% |
| Weight | 230g |
| Dimensions | 62*117*88mm |
| Display Size | 34.5mm×23mm; display area: 29.42mm×14.7mm |
| Enclosure Material | flame-retardant material(Indoor) |
| Protection Rating | IP20(Indoor) |
| Mounting | 35mm DIN Rail(Indoor) |
| Communication | RS485 |
| Protocol | Modbus |
Monitoring Functions
| Grounding Resistance | 0.01Ω~2000Ω, 0.01Ω |
| Measurement Method | Precision 3-Wire Measurement |
| Measurement Time | 1min/orders |
| Grounding Resistance Accuracy | ±2%rdg±3dgt |
| Ground Voltage | 0.1V~600V, 0.1V |
| Voltage Accuracy | ±2%rdg±5dgt |
| Acquisition Points | Resistance + Ground voltage |
| Acquisition Method | 3-point method |
Installation Instructions
Installation Example
Interface Diagram
Interface Definition
| No. | Definition |
|---|---|
| 1 | Power positive (VCC) |
| 2 | Power ground (GND) |
| 3 | RS485 A terminal (T/A) |
| 4 | Communication ground (GND) |
| 5 | RS485 B terminal (R/B) |
| 6 | C terminal (current electrode) |
| 7 | Reserved terminal |
| 8 | P terminal (voltage electrode) |
| 9 | E terminal (grounding electrode) |
| 10 | LCD screen |
| 11 | Down button |
| 12 | Confirm & Test button |
| 13 | Down button |
| 14 | Mounting hole |
| 15 | Clip |
| 16 | DIN rail slot (35mm) |
Key Points
- Definition： The Indoor Ground Resistance Monitor is FEXLINK's indoor device for online ground-grid resistance monitoring in electrical rooms, supporting continuous measurement without power interruption.
- Core Capabilities： Continuous online ground-resistance monitoring without power outage; supports RS485 upload; integrates with smart lightning protection systems.
- Scenarios： Suitable for continuous indoor grounding system monitoring in electrical rooms, equipment rooms and telecom base stations.
- Related Products： FR Three-Point Ground Resistance Monitor, FG Smart Gateway, FEXLINK Cloud grounding monitoring solution.
Frequently Asked Questions
Product FAQ
What is Indoor Ground Resistance Monitor?
The Indoor Ground Resistance Monitor is FEXLINK's indoor device for online ground-grid resistance monitoring in electrical rooms, supporting continuous measurement without power interruption.
What scenarios does Indoor Ground Resistance Monitor apply to?
Suitable for continuous indoor grounding system monitoring in electrical rooms, equipment rooms and telecom base stations.
How does Indoor Ground Resistance Monitor differ from traditional solutions?
Compared with manual periodic megger testing, the indoor monitor provides continuous online monitoring without on-site personnel and Real-Time data upload.
How is Indoor Ground Resistance Monitor installed and integrated?
DIN-rail mount inside the distribution cabinet, wire per the auxiliary-electrode and main-unit code, and configure the sampling interval.
How can I purchase FEXLINK products or request a demo?
Submit requirements via the Contact page on the FEXLINK website, or call +86-755-8653-6148 to request a demo and selection consultation; engineers will propose a matched solution and quotation based on your scenario.
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FEXLINK Business Scope
FEXLINK specializes in smart lightning protection and electrical safety, offering a product portfolio covering lightning protection, lightning online monitoring, lightning protection online monitoring, lightning arrester, intelligent lightning arrester, lightning arrester monitoring, grounding resistance, grounding monitoring for smart lightning protection scenarios, while addressing digital distribution, smart distribution, electricity meter, carbon neutral, industrial internet, carbon asset for digital business, helping enterprises achieve safe, efficient and low-carbon energy management.