Electrical Safety

ESB Three-Phase Unbalance Monitor

Exclusive Zero-Sequence/Negative-Sequence Unbalance Monitoring, Precisely Locating Grid Imbalance Root Causes

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0.2 Class
Measurement Accuracy
130+
Monitoring Parameters
<2%
Unbalance Error
Zero/Negative Sequence Decomposition OLED Display Modbus-RTU 35mm DIN Rail Mounting 0~6000A Range
Product Overview

Product Overview

ESB Three-Phase Unbalance Monitor is a smart monitoring terminal dedicated to in-depth unbalance diagnosis in low-voltage three-phase distribution systems. It dynamically computes zero-sequence voltage unbalance, negative-sequence voltage unbalance, zero-sequence current unbalance and negative-sequence current unbalance, and provides key indicators such as phase angle and voltage difference for each phase.

The product exclusively decomposes positive-, negative- and zero-sequence components to accurately locate the root cause of grid unbalance. Combined with a proprietary vector computation model, it directly provides 130+ monitoring items covering 17 parameters in 6 categories (voltage, current, power, energy, power factor, phase angle, unbalance, frequency), equivalent to 5 instruments in one.

Core Application Scenarios

  • Three-phase unbalance monitoring and mitigation in low-voltage distribution cabinets.
  • Precision power distribution balancing in data centers.
  • Power quality diagnosis and optimization for industrial production lines.
  • Smart power distribution O&M for commercial buildings.
Product Features

Product Features

Deep Unbalance Diagnosis

Exclusive monitoring of zero-sequence and negative-sequence voltage/current unbalance, decomposing positive/negative/zero-sequence components, accurately locating the abnormal phase.

130+ Parameters in One Table

6 categories 17 parameters: voltage/current/power/energy/power factor/phase angle/unbalance/frequency, equivalent to 5 instruments in one.

Industry-Leading Accuracy

Voltage and Current Measurement Accuracy up to Class 0.2, unbalance measurement error <2%, accuracy 10 times stricter than national standard, frequency accuracy 0.01Hz.

Multi-Level Smart Alarm Linkage

Supports 8 alarm types: overvoltage/undervoltage/overcurrent/overpower/voltage unbalance/current unbalance/undercurrent/underpower, "AND/OR" logic programming, alarms on limit violation with automatic linkage.

HD OLED Display

OLED display shows real-time three-phase voltage, current and other key parameters, with exclusive unbalance analysis interface, transforming abstract issues into concrete values.

Remote Calibration & Open Data

Supports remote software calibration of current/voltage/power gain, 200+ read/write registers fully transparent, supports deep secondary development.

Selection Guide

Selection Guide

Model Naming Rules

ESB - 1 2 1 1 1 - R
1
Power
1=DC 5V / 2=AC 220V
2
Display
1=7-segment / 2=OLED
3
Wiring
1=Three-phase four-wire
4
Current Parameter
1=5A / 2=100A / 3=400A / 4=600A
5
I/O
1=1-channel relay output+2-channel digital input
6
Communication
R=RS485
Model Power Supply Display Current Rating Voltage Rating DI Inputs Relay Output RS485 Modbus
ESB-12111-R DC 5V OLED 3×5A 3×220/380V 2-ch 1-ch Yes
ESB-12121-R DC 5V OLED 3×100A 3×220/380V 2-ch 1-ch Yes
ESB-12131-R DC 5V OLED 3×400A 3×220/380V 2-ch 1-ch Yes
ESB-12141-R DC 5V OLED 3×600A 3×220/380V 2-ch 1-ch Yes
ESB-22111-R AC 220V OLED 3×200A 3×220/380V 2-ch 1-ch Yes
ESB-22121-R AC 220V OLED 3×1000A 3×220/380V 2-ch 1-ch Yes
ESB-22131-R AC 220V OLED 3×400A 3×220/380V 2-ch 1-ch Yes
ESB-22141-R AC 220V OLED 3×600A 3×220/380V 2-ch 1-ch Yes

* Other electrical parameters include: frequency, power, power factor, etc. For other ranges or communication configurations, please contact sales for customized solutions.

Technical Parameters

Technical Parameters

Basic Parameters

Operating VoltageDC 4.75~5.25V(5V model)/ AC 180~250V(220V model)
Power Consumption≤ 2W
Operating Temperature-20℃ ~ 60℃
Operating Humidity< 95%
Weight150g
Dimensions36 × 110 × 69mm(L×W×H)
Enclosure MaterialThermoplastic UL94V0
Protection RatingIP20
MountingStandard 35mm DIN Rail Mounting
DisplayOLED
CommunicationRS485
ProtocolModbus

Monitoring Functions

Voltage (AC) Rated: 220V/380V; overload: 1.2x rated continuous, 2x rated for 1 second; Accuracy: Class 0.5/0.2S
Current (AC) Rated: 5A, 100A, 400A, 600A; overload: 1.2x rated continuous, 2x rated for 1 second; Accuracy: Class 0.5/0.2S
Frequency 45~65Hz, accuracy: 0.01Hz
Active Energy Accuracy: Class 1
Reactive Energy Accuracy: Class 2
Three-Phase Unbalance Zero-sequence/negative-sequence Voltage/Current unbalance, unbalance measurement error <2%
DI Input Dry contact input, built-in power,2-channel
DO Output Relay output, contact capacity AC250V/3A, DC30V/3A, normally open contact
Installation Instructions

Installation Instructions

a

Installation Dimensions

ESB Three-Phase Unbalance Monitor installation dimensions
ESB Three-Phase Unbalance Monitor DIN rail mounting
36mm
Width
110mm
Height
69mm
Depth
35mm
Standard DIN Rail
b

Sensor Description

The product uses external three-phase current transformers, with different rated values corresponding to different aperture specifications. Split-core design enables installation without power outage, dedicated high-precision sensors with patented smart locking design ensure high stability in complex environments.

Current sensor 5A
5A
Aperture 16mm
Current sensor 100A
100A
Aperture 24mm
Current sensor 200A
200A
Aperture 36mm
Current sensor 400A
400A
Aperture 36mm
Current sensor 600A
600A
Aperture 36mm
Current sensor 1000A
1000A
Aperture 52mm
Rated Value Current Ratio Aperture
5A5A / 0.33V16mm
100A100A / 0.33V24mm
200A200A / 0.33V36mm
400A400A / 0.33V36mm
600A600A / 0.33V36mm
1000A1000A / 0.33V52mm
c

Interface Diagram

ESB Three-Phase Unbalance Monitor Interface diagram

Wiring Definition

Power Supply 220V: L1 live, N neutral; 5V: 5V positive, GND 0V (alternative)
RS485 Communication A: RS485 A terminal; B: RS485 B terminal
DI Input DI1/DI2: Digital input, the other end connects to GND, direction-independent
DO Output DO1/DO1': Relay output, direction-independent
Current Input IA+/IA-, IB+/IB-, IC+/IC-: Three-phase Current positive/negative terminals
Voltage Input L1/L2/L3: Three-phase Voltage; N: Neutral

Note: 220V AC input and 5V DC power input are mutually exclusive. Do not connect both simultaneously.