ESM Full-Factor SPD Terminal
ESM Series
Self-developed 10uA leakage-current sensor, monitoring leakage/temperature/voltage/lightning-count/grounding/remote-signaling, with proprietary life prediction and health records.
Product Overview
Full-factor SPD monitoring (ESM lightning protection monitoring module) is a full-factor SPD intelligent monitoring terminal integrating "measure, compute, display, and intelligence" in one unit. The product's self-developed 10μA leakage current sensor delivers a 100x accuracy improvement. With algorithm models trained on massive usage data, it achieves multi-dimensional status monitoring and degradation analysis. It monitors leakage current, body temperature, voltage, lightning strike count, grounding status, SPD remote signal, and upstream circuit breaker status in real time, dynamically calculates a 0~100.0% life value based on 4 key factors, and builds a fine-grained SPD health profile, leaving no hidden risk undetected. Widely applied in parks, railways, ports, airports, agriculture, mining, equipment, meteorology, water utilities, environmental protection, and new energy, it is an ideal "IoT + lightning protection" terminal that leverages high-precision feature data capture and analysis to deliver true degradation trend and degradation ratio functions.
Core Capabilities
Microampere-level leakage current monitoring (10.0~3000.0μA) for early degradation warning. Precision temperature tracking (-30~125°C) to prevent thermal breakdown. 0.1kA-sensitive lightning strike counting, recording 0~9999 surge events. Exclusive life estimation algorithm to quantify remaining value. Product Features
Data Generated
Product Features
10μA-Level Leakage Current Sensing
Self-developed 10μA leakage current sensor with a 100x accuracy improvement. Algorithm models trained on massive usage data enable multi-dimensional status monitoring and degradation analysis.
Exclusive Life Estimation Algorithm
Dynamically calculates a 0~100.0% life value based on 4 key factors - remote signal, count, temperature, and leakage current - with programmable alarm thresholds, shifting from "replacement after failure" to "maintenance before failure".
Multi-Level Intelligent Alarm Linkage
Supports dual protection of local audible/visual alarms and remote communication. Thresholds can be configured for leakage current >3000μA, temperature >60°C, or life
Open Protocol, Seamless Integration
Standard Modbus RTU protocol with 200+ read/write registers fully open. Supports RS485 networking and MQTT cloud access, with configurable byte order and zero integration barriers.
Full-Factor Status Visibility
Use the panel buttons to navigate multi-level query menus to view full-dimensional data including SPD life, three-phase leakage current, temperature, voltage, lightning strike count, and grounding, making hidden risks precisely visible.
Compact, Flexible and Convenient
Default LED digital tube display with optional OLED screen; physical buttons for convenient on-site query and configuration; pluggable terminals, 35mm DIN-rail mounting, and a compact 36mm width for easy installation even in tight spaces. Selection Guide
System Topology
Selection Guide
Model Naming Rules
ESM - 1 1 1 1 2 - R 1 Power supply 1=DC5V / 2=AC220V 2 Display 1=LED digital tube / 2=OLED screen 3 Number of phases 0=none / 1=single-phase / 3=three-phase 4 Current parameter 0=none / 1=0.05~2.4mA (2.4mA/480mV silver coil) 5 Version 1=basic / 2=flagship R Communication method R=RS485 (Modbus) Model Power supply Display Digital inputs Grounding status Lightning strike count Temperature Leakage current channels Voltage channels Life estimation RS485 ESM-21001-R AC 220V LED digital tube 2 channels 1 channel 1 channel 1 channel --- --- --- Supported ESM-11112-R DC 5V OLED 2 channels 1 channel 1 channel 2 channels 1 channel 1 channel Supported Supported ESM-11312-R DC 5V OLED 2 channels 1 channel 1 channel 2 channels 3 channels 3 channels Supported Supported ESM-21112-R AC 220V OLED 2 channels 1 channel 1 channel 2 channels 1 channel 1 channel Supported Supported ESM-21312-R AC 220V OLED 2 channels 1 channel 1 channel 2 channels 1 channel 3 channels Supported Supported * Digital input monitoring is used to monitor SPD remote signals and upstream circuit breaker status. For other configurations, please contact sales for a customized solution. Technical Parameters
| Model | Power supply / Display / Digital inputs / Grounding status / Lightning strike count / Temperature / Leakage current channels / Voltage channels / Life estimation / RS485 |
| ESM-21001-R | AC 220V / LED digital tube / 2 channels / 1 channel / 1 channel / 1 channel / — / — / — / Supported |
| ESM-11112-R | DC 5V / OLED / 2 channels / 1 channel / 1 channel / 2 channels / 1 channel / 1 channel / Supported / Supported |
| ESM-11312-R | DC 5V / OLED / 2 channels / 1 channel / 1 channel / 2 channels / 3 channels / 3 channels / Supported / Supported |
| ESM-21112-R | AC 220V / OLED / 2 channels / 1 channel / 1 channel / 2 channels / 1 channel / 1 channel / Supported / Supported |
| ESM-21312-R | AC 220V / OLED / 2 channels / 1 channel / 1 channel / 2 channels / 1 channel / 3 channels / Supported / Supported |
Technical Parameters
Basic Parameters
Operating voltage DC 4.75~5.25V (5V version) / AC 160~280V (220V version) Power consumption ≤ 2W Operating temperature -20℃ ~ 60℃ Operating humidity < 95% Product weight 150g Dimensions 36 × 110 × 69mm (L×W×H) Housing material Thermoplastic material UL94V0 Protection rating IP20 Installation method Standard 35mm DIN-rail mounting Display LED digital tube / OLED (optional) Communication RS485 Communication protocol Modbus
| Operating voltage | DC 4.75~5.25V (5V version) / AC 160~280V (220V version) |
| Power consumption | ≤ 2W |
| Operating temperature | -20℃ ~ 60℃ |
| Operating humidity | < 95% |
| Product weight | 150g |
| Dimensions | 36 × 110 × 69mm (L×W×H) |
| Housing material | Thermoplastic material UL94V0 |
| Protection rating | IP20 |
| Installation method | Standard 35mm DIN-rail mounting |
| Display | LED digital tube / OLED (optional) |
| Communication | RS485 |
| Communication protocol | Modbus |
Monitoring Functions
Digital inputs Dry contact inputs with built-in power supply, 2 channels (monitoring SPD remote signals and upstream circuit breaker status) Grounding status Ground loop monitoring, 1 channel Lightning strike count 0~9999 times, minimum trigger 0.1kA Temperature NTC measurement: -30~125°C, accuracy ±1°C Leakage current (AC) 50.0~2400.0μA, accuracy ±20μA Voltage (AC) 0~600.0V, accuracy ±1V Life estimation 0~100.0%, dynamically calculated from remote signal/count/temperature/leakage current Alarm output Local audible/visual + remote communication, programmable thresholds Installation Instructions
| Digital inputs | Dry contact inputs with built-in power supply, 2 channels (monitoring SPD remote signals and upstream circuit breaker status) |
| Grounding status | Ground loop monitoring, 1 channel |
| Lightning strike count | 0~9999 times, minimum trigger 0.1kA |
| Temperature | NTC measurement: -30~125°C, accuracy ±1°C |
| Leakage current (AC) | 50.0~2400.0μA, accuracy ±20μA |
| Voltage (AC) | 0~600.0V, accuracy ±1V |
| Life estimation | 0~100.0%, dynamically calculated from remote signal/count/temperature/leakage current |
| Alarm output | Local audible/visual + remote communication, programmable thresholds |
Installation Instructions
a
Installation Dimension Drawing
36mm Width 110mm Height 69mm Depth 35mm Standard DIN rail b
Sensor Description
Sensor Specification Applicable version Lightning strike count magnetic ring Aperture 12mm, cable length 1m Basic, flagship Leakage current coil 4 turns, current ratio 2.4mA/480mV, aperture 11mm Flagship NTC temperature sensor Resistance 10kΩ (R25°C), cable length 15cm Basic, flagship c
| Sensor | Specification / Applicable version |
| Lightning strike count magnetic ring | Aperture 12mm, cable length 1m / Basic, flagship |
| Leakage current coil | 4 turns, current ratio 2.4mA/480mV, aperture 11mm / Flagship |
| NTC temperature sensor | Resistance 10kΩ (R25°C), cable length 15cm / Basic, flagship |
Interface Description
Wiring definition Terminal ID Name Description L / N Power L: live wire; N: neutral wire (220V version) 5V / GND Power 5V: positive; GND: 0V (5V version, choose one of 5V or 220V) A / B RS485 communication A: RS485 A terminal; B: RS485 B terminal DI1 Digital input 1 Remote signal input, other end connects to GND, non-directional DI2 Digital input 2 Circuit breaker input, other end connects to GND, non-directional T Temperature NTC temperature input, other end connects to GND, non-directional C+ / C- Lightning strike count Lightning strike count input, non-directional PE Grounding status Ground input, requires a loop between live wire L and ground Note: Choose only one of the 220V AC input or 5V DC power input - do not connect both simultaneously.
| Terminal ID | Name / Description |
| L / N | Power / L: live wire; N: neutral wire (220V version) |
| 5V / GND | Power / 5V: positive; GND: 0V (5V version, choose one of 5V or 220V) |
| A / B | RS485 communication / A: RS485 A terminal; B: RS485 B terminal |
| DI1 | Digital input 1 / Remote signal input, other end connects to GND, non-directional |
| DI2 | Digital input 2 / Circuit breaker input, other end connects to GND, non-directional |
| T | Temperature / NTC temperature input, other end connects to GND, non-directional |
| C+ / C- | Lightning strike count / Lightning strike count input, non-directional |
| PE | Grounding status / Ground input, requires a loop between live wire L and ground |
Key Points
Definition: The SPD intelligent monitoring terminal is FEXLINK's universal monitoring device for online surge protective device (SPD) status monitoring, compatible with multiple SPD types. Core capabilities: collects SPD leakage current, temperature, lightning strike count, and remote signal status, supports RS485/MQTT upload, and can connect to FEXLINK Cloud. Applicable scenarios: online SPD status monitoring in power distribution rooms and smart lightning protection system construction. Related products: FSS intelligent surge protective device, FS surge protective device monitor, ESX intelligent edge computing gateway.
FAQ
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