Technology of Electrical Automatic

ZJS-102 DC System Insulation Monitor

ZJS-102 DC System Insulation Monitor

The ZJS-102 DC System Insulation Monitor employs the pure DC leakage current monitoring principle, featuring both balanced bridge and unbalanced bridge detection modes. It provides a real-time display of the leakage current for each circuit. The ZJS-102 online insulation monitoring system offers comprehensive DC insulation fault monitoring, capable of detecting various ground faults in the DC system. These include single-point grounding, multi-point grounding, two-pole grounding, AC intrusion, DC mutual interference, battery grounding and positioning, voltage balance, timing detection, pressure difference alarm, automatic calibration, and more. Additionally, it features instantaneous grounding monitoring and line selection alarm functions.

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The ZJS-102 DC System Insulation Monitor employs the pure DC leakage current monitoring principle, featuring both balanced bridge and unbalanced bridge detection modes. It provides a real-time display of the leakage current for each circuit. The ZJS-102 online insulation monitoring system offers comprehensive DC insulation fault monitoring, capable of detecting various ground faults in the DC system. These include single-point grounding, multi-point grounding, two-pole grounding, AC intrusion, DC mutual interference, battery grounding and positioning, voltage balance, timing detection, pressure difference alarm, automatic calibration, and more. Additionally, it features instantaneous grounding monitoring and line selection alarm functions.

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Overview

The online insulation monitoring system comprises three essential components: the main controller (host), the current collector, and the dedicated DC leakage current sensor. The main controller serves as the central control unit for the entire system, functioning as the primary interface for monitoring information display and setting information input. Sensors are installed at each DC feeder outlet loop. Positioned between the host and the sensor, the current collector offers flexibility in installation location based on requirements. It can be directly linked to the host via the communication bus or indirectly connected through the cascade port of another slave machine, simplifying installation and wiring. Each current collector can connect with up to 8 sensors.

components of ZJS-102 online insulation monitoring system

Working principle of ZJS-102 online insulation monitoring system
In balanced bridge detection mode, the insulation monitor computes the system’s equivalent resistance to the ground by utilizing the system-to-ground voltage. It then determines the equivalent resistance value for each branch based on the current returned by individual current detectors. In unbalanced bridge detection mode, the online insulation monitoring system utilizes the internal unbalanced bridge to calculate the actual positive and negative resistance of the system to the ground. Subsequently, it calculates the actual positive and negative resistance of each branch to the ground based on the current change values from each current detector under the unbalanced bridge.

Apart from the manually set working modes, the insulation monitor device can enter various working modes based on user-selected function items. These include balanced bridge calculation mode, voltage balance mode, instantaneous ground detection mode, and waiting mode.

working principle insulation monitoring system Conversion relationships between modes

Function & Feature of Insulation Monitoring System

  • Real-time monitoring of system AC and DC voltage and alarm

Real-time monitoring of system bus-to-ground voltage, including system voltage, positive-to-ground voltage, negative-to-ground voltage, and AC channeling voltage, and displays them in real-time. When the voltage exceeds the preset setting value, the host LCD screen displays alarm information, and the voltage over-limit indicator light and buzzer alarm simultaneously.

  • Real-time monitoring of system insulation and alarms

Real-time monitoring of system bus-to-ground impedance, including positive-to-ground resistance and negative-to-ground resistance, and displays them in real-time. When a fault occurs in the DC system and the positive and negative voltages to the ground are no longer balanced and exceed the preset setting value, the host LCD screen displays an alarm message, and the system grounding indicator light and buzzer alarm at the same time.

  • Instantaneous ground recording function

This insulation monitor can set instantaneous ground sampling wave recording functions at different frequencies such as 1KHz, 500Hz, 250Hz, and 125Hz. Each record provides 8-channel waveforms, including positive and negative ground voltages and up to 6 instantaneous ground loop currents.

  • Grounding history analysis

The insulation monitoring system can automatically save AC current leakage and grounding records in EEPROM, including detailed information such as date and time, ground impedance, leakage voltage, etc., while providing complete historical records, including system and loop fault information.

  • Voltage balancing function

The insulation monitor employs an internal ground voltage deviation compensation bridge to rectify the DC system ground voltage to a balanced state if the ratio of the DC system negative bus voltage to ground surpasses 1.222 compared to the positive bus voltage.

  • Battery circuit insulation monitoring function

The insulation monitoring device monitors the battery circuit in real-time through a data collector and Hall sensor, detects insulation degradation or ground fault, and can also locate the number of faulty batteries. When using the monitoring function, the data collected by the corresponding Hall sensor is the real-time data of the battery circuit. data.

feature of dc system insulation monitor relay

  • The system-distributed capacitance detection function

It can detect the distributed capacitance of the DC system connected to this device.

  • Equipment self-test function

The insulation monitoring system self-tests each module when it is powered on, detects the connection status of the balance bridge in real-time during operation, and at the same time regularly detects the bridge connection status.

  • Circuit insulation classification warning
  • Loop leakage current detection and diagnosis
  • Real-time communication status monitoring function
  • Data upload and alarm output functions
  • Calibration and configuration functions
  • High-performance hardware

The host and collector use 32-bit industrial control CPUs and support up to dozens of CPUs running simultaneously. Each DC loop data acquisition channel uses an independent high-precision 16-bit AD converter, with a conversion speed of more than 1,000 times per second and a resolution of more than 1/50,000. The sensor resolution reaches 0.01m.

  • Advanced architecture, Smart software, and Humanized interface

 

Application of ZJS-102 online insulation monitoring system
The ZJS-102 insulation monitor is widely used in DC Systems including DC power supply, DC load, DC loop, and related control and monitoring equipment. It is commonly used to monitor Grounding resistance and Insulation decreasing of DC bus and branch circuits in industrial or utility substations.

ZJS-102 Insulation Monitor Display

zjs-102 dc system insulation monitor product display

Specifications

Monitoring range of system insulation resistance to ground
Earthing alarm 0-99.9K
Pre-warning 100-999.9K
Monitoring and detect range of branch insulation resistance to ground
0-300K
Working voltage range
Positive pole to ground 0-300V
Negative pole to ground 0-300V
System voltage 0-300V
AC injection voltage 0-280V
Busbar-II system voltage (DC cross detect) 0-300V
Battery bank insulation fault location error ±1 cell
Alarm history record
Record list quantities 2000 lists
Each record alarm list volume ≤32 branches
Real-time leakage current measurement
Screen display resolution 0.01mA
Current sensor range 10mA, 20mA, 50mA, 100mA optional
Each ZJS-102 port detect current volume ≤ 240 branches
Each ZJS-CU collector unit connected current sensor ≤8
Instant event record
Capture sampling ratio 1KHz, 500Hz, 250Hz, 125Hz configurable
Record quantities 2000
Waveforms for each instantaneous event 8
Others
Passive digital output 7
Fault alarm indicator 6
Distributed capacitance range of the system 0-200uF
Voltage monitoring error ≤0.5%
Communication interface RS485, Ethernet
System voltage balance compensation bridge 40K, 60K, 120K;
Optional AUX 220Vac

Typical wiring

Typical wiring of ZJS-102 DC System Insulation Monitor

Notes:

1*ZJS-102 can connect max 30pcs ZJS-CU.

1*ZJS-CU can connect 8pcs of CT, to monitor 8 feeder loops.

CT can selection depends on feeder cable diameter, please contact our sales team for more help.

Products do not include wiring cable, Blue Jay suggest use CAT5e cable.

Downloads

Brochure of IMD-SERIES-DC-INSULATION-MONITORING-DEVICES

ZJS-102-User manual V1.11

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