Suzhou Gongyuan Automation Technology Co., Ltd. | Electrical Safety Monitoring for New Energy Systems
WhatsApp: +86 18813093352 / +86 16606190906   |   Email: dongbin.zhang@bjgongyuan.com
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Certified obtained from TUV
DC Insulation Monitoring Device Manufacturer for EV Charging, Energy Storage and Solar PV

Gongyuan develops DC, AC, and high-voltage insulation monitoring solutions for EV charging, energy storage, photovoltaics, industrial distribution, and rail transit.

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1000+
New energy enterprises served
TUV / CE
International product certification
DC / AC
Insulation monitoring portfolio
RS485
MODBUS RTU data communication
hom e1786448232963
1000~4000Vd.c.

High-voltage DC monitoring with self-test, relay alarm, and MODBUS RTU.

What Is an Insulation Monitoring Device?

An insulation monitoring device (IMD) continuously measures the insulation resistance between an ungrounded (IT) power system and earth. When the resistance falls below a set threshold, it raises an alarm before a second fault causes a short circuit, fire or electric shock. IMDs are used in DC EV chargers, battery energy storage, solar PV and rail systems.

In an ungrounded system, the first insulation fault does not trip a breaker, so the system keeps running and the fault stays hidden. An IMD makes that hidden fault visible. It injects a small measuring signal, calculates the resistance of the positive and negative poles to earth, and reports the value in kΩ or MΩ over RS485, CAN or a relay contact.

  • Measuring range: Gongyuan monitors measure from 0 kΩ up to 50 MΩ, depending on the model.
  • Voltage range: models cover DC systems up to 4000 Vdc and AC systems up to 750 Vac.
  • Output: RS485 Modbus RTU, CAN bus and dry-contact relay alarm, depending on the model.
Product Center

DC Insulation Monitoring Device Manufacturer for EV Charging, Energy Storage and Solar PV

Gongyuan designs and manufactures TUV and CE certified insulation monitoring devices for DC and AC floating systems up to 4000 Vdc. Engineers at charger, battery storage and PV companies use our monitors to detect insulation faults early, before they cause a shutdown, fire or electric shock.

Product Categories

Insulation Monitor - DC Applications / AC Applications / Supporting LCD Screen

GYIM-DAR DC Insulation Monitor Device
Multi-Circuit Applications

GYIM-DAR DC Insulation Monitor Device

Real-time monitoring of positive and negative pole insulation resistance, unaffected by DC voltage fluctuation.

  • 100~1000Vd.c. DC floating system
  • 0kΩ~10MΩ resistance measurement
  • RS485 communication, MODBUS RTU protocol
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GYDCG-UBCW2K High Voltage Insulation Monitor
2000V System

GYDCG-UBCW2K High Voltage Insulation Monitor

Designed for DC charging systems, photovoltaic systems, energy storage systems, and DC grid applications.

  • 100~2000Vd.c. monitoring range
  • Insulation monitoring module self-test
  • Dry contact relay alarm output
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GYID Insulation Monitoring Device
AC / DC Applications

GYID Insulation Monitoring Device

Monitors DC floating systems, AC floating systems, passive equipment insulation status, and vehicle systems.

  • 0~1000Vd.c. DC and 0~750Va.c. AC
  • Measurement range up to 50MΩ
  • CAN bus communication interface
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GYDCG-MBC1500 Multi-Branch DC Insulation Monitor
Multi-Circuit Applications

GYDCG-MBC1500 Multi-Branch DC Insulation Monitor

Simultaneous monitoring for multi-branch circuits in power distribution systems.

  • Up to 30 separate monitoring channels
  • RS485 / Modbus communication standard
  • LCD display for local interface
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GYDCG-UBCW4K 4000 Vdc Insulation Monitor
AC / DC Applications

GYDCG-UBCW4K 4000 Vdc Insulation Monitor

High-performance insulation monitoring designed for heavy industrial systems.

  • Extended voltage range up to 4000Vdc
  • Robust construction with sealing caps
  • Features a dry-contact relay output for alarms
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GYDCG-UBCH1 Multifunction DC Insulation Monitor
Multi-Function

GYDCG-UBCH1 Multifunction DC Insulation Monitor

Versatile and compact insulation monitoring with programmable settings.

  • Compact DIN-rail mount design
  • Programmable alarm thresholds
  • Optional vehicle DC voltage and shunt voltage monitoring
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GYID AC/DC Insulation Monitoring Device
AC / DC Applications

GYID AC/DC Insulation Monitoring Device

Monitors DC floating systems, AC floating systems, passive equipment insulation status, and vehicle systems.

  • 0~1000Vd.c. DC and 0~750Va.c. AC
  • Measurement range up to 50MΩ
  • CAN bus communication interface
Request a Quote →
DMG10600T070_A5WTR Supporting LCD Screen
Supporting Screen

DMG10600T070_A5WTR Supporting LCD Screen

Interactive high-resolution smart display terminal designed for real-time monitoring system parameters.

  • 7-inch HD touch screen display
  • Adjustable parameter settings
  • RS485 communication interface
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Insulation Monitoring Devices up to 4000 Vdc

Choose by system voltage first, then by the number of circuits and the communication your controller uses. Every model below is designed and built by Gongyuan in Suzhou, China.

ModelSystem voltageMeasuring rangeCommunication / output
GYIM-DAR100–1000 Vdc0–10 MΩRS485 Modbus RTU
UBCW2K100–2000 Vdc0–10 MΩRS485 Modbus RTU + relay
UBCW4K1000–4000 Vdc0–50 MΩRS485 Modbus RTU + relay
MBC1500up to 1500 Vdc, 30 branchesproduct page par nahiRS485
UBCH1100–1000 Vdc0–10 MΩRS485, proprietary protocol (Modbus nahi)
GYID AC/DC0–1000 Vdc / 0–750 Vac0–50 MΩCAN bus
About Us

Why Buyers Choose Gongyuan as Their IMD Manufacturer

Suzhou Gongyuan Automation Technology Co., Ltd. has designed and manufactured insulation monitoring devices since 2017. Insulation monitoring is our core product line, not one item in a catalogue of meters and relays.

Our R&D team builds monitors for DC and AC floating systems up to 4000 Vdc, used in EV chargers, energy storage, solar PV and rail transit. Buyers work directly with the factory that designs, builds and supports the product.

2017
Founded in the insulation monitoring industry
56+
Patent and intellectual property achievements
100+
Product and solution capability
1000+
New energy enterprise customers served
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Insulation Monitoring Solutions by Application

EV Chargers and DC Charging Piles

DC charger outputs are isolated from earth, so an insulation fault in the cable, connector or vehicle does not trip a breaker. An IMD checks insulation before and during charging and stops the session when resistance drops.

Battery Energy Storage Systems (BESS)

Storage containers run long DC strings at up to 1500 V, where condensation, coolant leaks or damaged cables slowly lower insulation. Multi-branch monitoring shows which rack or cluster is failing before the whole container shuts down.

Solar PV Systems

PV arrays sit outdoors for 25 years and their insulation ages with sun, moisture and rodents. Continuous monitoring finds a ground fault early, instead of waiting for an inverter isolation alarm. Recommended: GYDCG-UBCW2K, GYIM-DAR.

Rail Transit and Industrial DC Systems

Rail auxiliary power, substations and industrial DC panels cannot afford an unplanned stop. Gongyuan monitors give early warning in DC and AC floating systems and report over Modbus to your SCADA. Recommended: GYID AC/DC, GYIM-DAR, GYDCG-MBC1500.

Why Choose Us

What Global Buyers Get From Gongyuan

A factory that designs, builds and supports its own insulation monitors, so you get the right model, the right documents and fast answers from engineers.

01

High-Voltage Range

Monitors for DC floating systems from 100 Vdc up to 4000 Vdc, with measuring range up to 50 MΩ.

02

Proven in New Energy

Used in EV chargers, storage cabinets, PV systems, DC grids and rail transit by 1000+ customers.

03

Certified and Documented

TUV and CE certified, with RoHS and REACH SVHC reports ready to download for supplier approval.

04

Fast Engineering Support

Send your voltage and application. Our engineers reply with a model recommendation, datasheet and certificates.

Solutions & Application Areas

How to Choose the Right Insulation Monitor

What is the maximum system voltage?

Up to 1000 Vdc: GYIM-DAR or GYID. Up to 2000 Vdc: GYDCG-UBCW2K. 1000–4000 Vdc: GYDCG-UBCW4K.

Is it DC, AC, or both, and how many circuits?

One DC circuit: a single-channel monitor. Many feeders or battery clusters: GYDCG-MBC1500 with up to 30 channels. Mixed AC and DC: GYID AC/DC.

How will it report alarms?

Modbus RTU over RS485 to a PLC or SCADA, CAN bus to a charger or vehicle controller, or a dry-contact relay to trip or signal locally.

Application Cases

Field-Proven New Energy Applications

Application photos show real integration in charging equipment and electrical systems.

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Charging Pile Integration

Integrated insulation monitoring inside charging equipment cabinets.

爱普拉充电机应用

EV Charger Safety

Supports safety warning in DC charging applications.

德利势

Industrial DC Systems

Monitoring for high-reliability power and equipment systems.

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New Energy Projects

Application coverage for charging, storage, photovoltaic, and DC grids.

Certifications & Technical Documents

Compliance Materials for Procurement

Clear proof for safety review, quality checks, and market-entry evaluation.

Compliance Snapshot

Verified documents for faster buyer approval.

TÜV, CE, RoHS, REACH, quality system, and patent materials support engineering and procurement review.

TUV认证

TUV

Product safety validation

CE

EU market conformity

RoHS

Restricted substance control

REACH

SVHC report available

TUV认证
CE证书
QUALITY MANAGEMENT SYSTEM CERTIFICATE 01
1 实用新型 2023219388333 直流绝缘监测仪快速安装结构 证书 01 1

Certificate PDF

TUV Certificate

Open document →

Certificate PDF

RoHS Certificate

Open document →

ISO 9001 Certificate

REACH SVHC Report

Open document →
Online Inquiry / Technical Support

Request a Quote for Your Voltage Range

Tell us your system voltage, application and communication protocol. Our engineers will reply with a recommended model, datasheet and certificates.

  • Model selection
  • Certification files
  • Technical parameters
  • Project integration
News & Information

Technical Articles and Insights

Guides for insulation monitoring principles, safety value, product selection, and maintenance.

IMD vs RCD: What Is the Difference and When to Use Each

IMD vs RCD is a common question among electrical engineers designing EV charging systems, battery energy storage systems, industrial DC networks, and other critical electrical applications. Both devices are designed to improve electrical safety, but they solve different protection challenges. Choosing the wrong device can result in missed faults, unnecessary shutdowns, or reduced system reliability. […]

DC Ground Fault Detection Methods: How to Find a Ground Fault in a DC System

Short answer: The main DC ground fault detection methods are the balanced bridge, the unbalanced bridge, low-frequency signal injection, branch leakage current sensors and portable locators. The first three detect that a fault exists. The last two help locate which circuit it is on. A ground fault in a DC system is an unwanted conductive […]

Insulation Monitoring for Battery Energy Storage Systems: 1500 V BESS Guide

DC insulation detection supports uptime, preventive maintenance, and safer operation in PV, storage, and DC grid projects.

How Does an Insulation Monitoring Device Work? IMD Working Principle Explained

Insulation monitoring helps teams detect degradation before it becomes a safety risk, especially in floating DC and new energy systems.

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