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Smart Lightning Protection

FR Ground-Resistance Detector

FR Series

Three-point / precision three-wire ground-resistance online monitoring, 0.01-2000 Ohm range, real-time sensing of grounding-system status, ensuring effective lightning protection.

Three-point / precision three-wire0.01-2000 OhmOnline monitoringGrounding status
FR Ground-Resistance Detector

Product Overview

The FR three-point method ground resistance monitoring module monitors ground resistance, bond resistance and other data, accurately recording ground resistance values with a monitoring accuracy of up to 0.001Ω. It uses the precision three-wire measurement method and automatically takes multiple measurements to average, ensuring accurate and reliable results. The housing is made of aluminum alloy (corrosion-resistant design, impervious to wind, rain and lightning), with a protection rating up to IP65 and an operating temperature of -20℃~60℃, suitable for long-term operation in harsh outdoor environments. It supports outdoor installation, clamp mounting, buried installation and wall-mounted installation, and can be used independently or in a network.

Core capabilities

Monitors ground resistance and bond resistance with accuracy up to 0.001Ω. Aluminum alloy corrosion-resistant housing with IP65 protection, impervious to wind, rain and lightning. On-site alarms and networked remote alarms, with real-time notification of abnormal status. RS485/Zigbee/Ethernet/4G multiple communication methods to connect to the cloud service system. Product Features

Data GeneratedThree-point / precision three-wire0.01-2000 OhmOnline monitoringGrounding statusProduct FeaturesComplete monitoring, high accuracy

Monitors ground resistance, bond resistance and other data, accurately recording ground resistance values with a monitoring accuracy of up to 0.001Ω.

Strong weather resistance

Aluminum alloy material (corrosion-resistant design, impervious to wind, rain and lightning) with a protection rating up to IP65, suitable for long-term operation in harsh outdoor environments.

Smart alarm push

Features on-site alarms and networked remote alarms, supports historical data queries, and notifies O&M personnel of abnormal status in real time.

Multiple communication options

Can connect to the gateway via RS485/Zigbee/Ethernet/4G etc., transmitting all kinds of data to the cloud service system.

Wide temperature range, strong weather resistance

Operating temperature of -20℃~60℃, aluminum alloy corrosion-resistant housing impervious to wind, rain and lightning, suitable for long-term operation in harsh outdoor environments.

Quick-swap modular design

Modular structure allows quick on-site replacement during maintenance, reducing downtime and improving maintenance efficiency. Selection Guide

System TopologyPerception LayerElectrical Parameters · Leakage Detection · Temperature · Arc · Lightning Current · SPD StatusEdge LayerEdge Gateway · Smart Circuit Breaker · Protocol Acquisition · Rule EnginePlatform LayerFEXLINK Cloud · W-Link · Device Access · Data StorageApplication LayerIndustrial AI Analysis · Virtual Power Plant · Energy Monitoring · Carbon Assets · Carbon-Neutral ParkSelection GuideModel naming convention

FR - 0 1 0 1 1 - R FR Product: Three-point method ground resistance monitoring module 0 Display: 0=none; 1=yes 1 Signal acquisition: 1=grid resistance; 2=grid resistance + ground voltage 0 Explosion-proof: 0=none; 1=yes 1 Mounting method: 1=outdoor; 2=indoor DIN rail; 3=indoor screw 1 Power supply: 1=DC12V; 2=AC220V; 3=solar; 4=lithium battery R Communication: R=RS485; E=Ethernet; Z=Zigbee; G=4G Model Installation position Measurement method Explosion-proof Acquisition point RS485 ZIGBEE Ethernet 4G FR-01011-R Outdoor Three-point method None Grid resistance √ --- --- --- FR-01011-Z Outdoor Three-point method None Grid resistance --- √ --- --- FR-01011-E Outdoor Three-point method None Grid resistance --- --- √ --- FR-01011-G Outdoor Three-point method None Grid resistance --- --- --- √ FR-02011-R Outdoor Three-point method None Resistance + ground voltage √ --- --- --- FR-02011-Z Outdoor Three-point method None Resistance + ground voltage --- √ --- --- FR-02011-E Outdoor Three-point method None Resistance + ground voltage --- --- √ --- FR-02011-G Outdoor Three-point method None Resistance + ground voltage --- --- --- √ Technical Parameters

ModelInstallation position / Measurement method / Explosion-proof / Acquisition point / RS485 / ZIGBEE / Ethernet / 4G
FR-01011-ROutdoor / Three-point method / None / Grid resistance / √ / --- / --- / ---
FR-01011-ZOutdoor / Three-point method / None / Grid resistance / --- / √ / --- / ---
FR-01011-EOutdoor / Three-point method / None / Grid resistance / --- / --- / √ / ---
FR-01011-GOutdoor / Three-point method / None / Grid resistance / --- / --- / --- / √
FR-02011-ROutdoor / Three-point method / None / Resistance + ground voltage / √ / --- / --- / ---
FR-02011-ZOutdoor / Three-point method / None / Resistance + ground voltage / --- / √ / --- / ---
FR-02011-EOutdoor / Three-point method / None / Resistance + ground voltage / --- / --- / √ / ---
FR-02011-GOutdoor / Three-point method / None / Resistance + ground voltage / --- / --- / --- / √

Technical Parameters

Basic parameters

Operating voltage DC 12V (default) / DC 24V/AC 220V (optional) Power consumption ≤2W Operating temperature -20℃~60℃ Operating humidity <95% Weight 7kg Dimensions 260*260*107mm Housing material Aluminum alloy Protection rating IP65 Mounting method Side mounting with M7 screws

Operating voltageDC 12V (default) / DC 24V/AC 220V (optional)
Power consumption≤2W
Operating temperature-20℃~60℃
Operating humidity<95%
Weight7kg
Dimensions260*260*107mm
Housing materialAluminum alloy
Protection ratingIP65
Mounting methodSide mounting with M7 screws

Smart monitoring functions

Communication RS485/Zigbee/Ethernet/4G Communication protocol Modbus/MQTT protocol Ground resistance 0.01Ω~2000Ω, resolution 0.01Ω Measurement method Precision three-wire measurement Measurement time 1 minute per measurement Ground resistance accuracy ±2%rdg±3dgt Ground voltage 0.1V~600V, resolution 0.1V Voltage accuracy ±2%rdg±5dgt Installation Instructions

CommunicationRS485/Zigbee/Ethernet/4G
Communication protocolModbus/MQTT protocol
Ground resistance0.01Ω~2000Ω, resolution 0.01Ω
Measurement methodPrecision three-wire measurement
Measurement time1 minute per measurement
Ground resistance accuracy±2%rdg±3dgt
Ground voltage0.1V~600V, resolution 0.1V
Voltage accuracy±2%rdg±5dgt

Installation Instructions

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Installation dimension drawing

260mm length 260mm width 107mm height M7 screw mounting b

Interface description

Interface definition No. Definition 1 Port 1: ground grid monitoring (E) 2 Port 2: auxiliary ground electrode 1 (P) 3 Port 3: auxiliary ground electrode 2 (C) 4 Port 4: communication port; Ethernet cable port for Ethernet communication; antenna port for wireless communication; no wiring for RS485 communication 5 Side port: DC12V power port for wireless or Ethernet communication, brown/blue two-core cable, brown-12V, blue-0V 6 Side port: for RS485, red-12V, black-0V, green-RS485_A, yellow-green-RS485_B

No.Definition
1Port 1: ground grid monitoring (E)
2Port 2: auxiliary ground electrode 1 (P)
3Port 3: auxiliary ground electrode 2 (C)
4Port 4: communication port; Ethernet cable port for Ethernet communication; antenna port for wireless communication; no wiring for RS485 communication
5Side port: DC12V power port for wireless or Ethernet communication, brown/blue two-core cable, brown-12V, blue-0V
6Side port: for RS485, red-12V, black-0V, green-RS485_A, yellow-green-RS485_B

Key Points

Definition: The FR three-point method ground resistance monitoring module is a FEXLINK device for online monitoring of outdoor grounding grid resistance, based on the three-pole measurement principle. Core capabilities: long-term online monitoring of ground resistance with strong anti-interference capability, suitable for harsh outdoor environments, uploading data via RS485. Applicable scenarios: monitoring of outdoor grounding systems such as oil storage tank areas, substations, communication base stations, and lightning rod grounding grids. Related products: ESX intelligent edge computing gateway, indoor ground resistance monitor, FEXLINK Cloud ground monitoring solution.

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Frequently Asked Questions

Which models and supply options does FR Ground-Resistance Detector offer?

FR Ground-Resistance Detector lists FR-01011-R, FR-01011-Z, FR-01011-E etc. in the specification table, with supply options including —.

How many digital inputs and monitoring channels does FR Ground-Resistance Detector provide?

Taking FR-01011-R as the example: — digital inputs, grounding status —, lightning count —, temperature —, leakage — and voltage channels —.

Which communication and output options does FR Ground-Resistance Detector support?

FR-01011-R supports RS485 / Modbus; choose the interface by the model suffix when connecting to a host system.

How should FR Ground-Resistance Detector be selected?

Fix the channel count by the number of monitored circuits first, then trim by grounding, lightning-count or voltage needs, and confirm the supply and communication suffix last.

What is the boundary of the FR Ground-Resistance Detector specification?

This page lists only the parameters in the specification table; anything outside it, such as ingress protection or mounting, follows the product documentation.