RMU MV HV Insulated Switchgear Panel with VCB

What Is It?

The RMU MV HV Insulated Switchgear Panel with VCB is a factory-assembled, metal-enclosed electrical distribution device combining Ring Main Unit (RMU) functionality with Vacuum Circuit Breaker (VCB) technology. The RMU enables ring network configuration—power can flow from either direction, ensuring supply continuity. The VCB, housed in a sealed vacuum interrupter, extinguishes arcs within milliseconds when faults occur.

RMU (Ring Main Unit) refers to a compact switchgear assembly designed for looped electrical networks. Unlike radial distribution systems where a single fault can cut power to entire downstream loads, an RMU enables you to create a ring configuration: power can flow from either direction. When a fault occurs on one section, you simply isolate that section while the rest of the network continues receiving power from the alternative feed.

VCB (Vacuum Circuit Breaker) is the heart of this panel's protection system. Inside a sealed vacuum interrupter, the circuit breaker can extinguish electrical arcs within milliseconds when a fault occurs. Because there is no air or oil inside the interrupter, the arc is quenched almost instantly, minimizing damage to downstream equipment and extending contact life.

MV HV Insulated Switchgear indicates that this product operates in the Medium Voltage to High Voltage range (typically 12kV to 40.5kV) and uses advanced insulation technology—either SF6 gas or solid dielectric—to isolate live parts from the environment.

What Can It Do?

1. Power Distribution Control – Switch circuits on/off manually or via SCADA

2. Fault Protection – Interrupt short-circuit currents up to 31.5kA

3. Network Isolation – Safely ground outgoing cables for maintenance

This panel enables utilities, industrial plants, and commercial buildings to achieve near-zero downtime while maintaining absolute personnel safety. Every RMU MV HV Insulated Switchgear Panel with VCB is built to perform in the harshest environments.

Product Parameter (Specification)

Product Feature And Application

Key Features

Integrated VCB Protection---Unlike standard RMUs with fuses, our RMU MV HV Insulated Switchgear Panel with VCB provides full-rated fault interruption. The vacuum interrupter requires no maintenance over its lifetime.

Sealed SF6 Insulation Tank---All live parts are housed in a 3mm stainless steel tank with <0.1% annual leakage. No cleaning, no insulation testing, no exposure to dust or salt fog.

Three-Position Switch-Disconnector Offers Connected, Disconnected, and Grounded positions with mechanical interlocking to prevent incorrect sequences.

Internal Arc Withstand---Tested at 20kA/1s with pressure relief directing hot gases away from the operator.

Compact Footprint---Occupies 30-50% less floor space than air-insulated switchgear, ideal for space-constrained substations.

Remote Monitoring---Standard auxiliary contacts plus optional Modbus or IEC 61850 communication.

Applications

● Urban power distribution (basement substations, commercial complexes)

● Wind and solar farms (withstands vibration, temperature extremes)

● Industrial plants (steel, cement, petrochemical)

● Data centers (Tier III/IV uptime requirements)

● Railway traction substations (25kV systems)

● Mining operations (dusty, humid environments)

Feature Q&A

Q: How does the VCB differ from a load-break switch?

A: A load-break switch interrupts normal load currents only. The VCB in this RMU MV HV Insulated Switchgear Panel with VCB interrupts fault currents up to 31.5kA in milliseconds, using a vacuum interrupter with no ionizable medium.

Production Details

Manufacturing Process

● Tank Fabrication---Laser-cut 316L stainless steel, robot-welded, X-ray inspected, pressure-tested at 0.4MPa for 24 hours.

● Vacuum Interrupter Assembly---Each interrupter undergoes 70kV AC high-voltage test and contact resistance measurement.

● SF6 Processing---Tank evacuated to <10Pa, then filled with SF6 gas (>99.97% purity, dew point <-50°C). Halogen sniffer checks all seals.

● Testing---Mechanical endurance (1,000 cycles), dielectric (70kV/1min), partial discharge (<5pC), and internal arc (20kA/1s) tests.

Quality Assurance & Certifications

Why Choose Lugao Power?

RMU with VCB vs RMU with Fuse

In general, VCB RMUs are recommended for medium- and large-capacity power distribution systems that require frequent switching operations, advanced protection, and remote monitoring. Fuse RMUs are a cost-effective solution for transformer protection and smaller distribution networks with relatively stable loads.

Packaging, Shipping & After-Sales

Packaging

1. VCI film inner wrap + foam padding + 9mm plywood crate

2. SF6 pressure reduced to 0.05MPa for transport

After-Sales & Warranty

1. Warranty Period: 12 months from commissioning or 18 months from shipment, whichever comes first.

2. Coverage: Material/workmanship defects, SF6 refill for leaks >0.5%/year, VCB vacuum loss.

3. Exclusions: Incorrect installation, force majeure, unauthorized modification, consumables.

Services:

1. Free remote troubleshooting (24-hour response)

2. Spare parts dispatch within 48 hours (regional warehouses)

3. Extended warranty available (2, 3, or 5 years)

Frequently Asked Questions 

Q1: Can you provide type test reports and FAT?

A: Yes. IEC type test reports available. Factory Acceptance Testing at our Zhejiang factory is welcome. Third-party inspection (SGS, BV) available at customer's cost.

Q2: How are warranty claims handled internationally?

A: Email photos/videos to lugaoteam@lugaoelectric.com. Remote diagnosis within 24 hours. For defects covered by the insurance, we will send replacement parts free of charge..

Q3: What is the expected service life of this RMU MV HV Insulated Switchgear Panel with VCB?

A: SF6 tank and busbars: 30 years. VCB interrupter: 10,000 operations or 30 years. Mechanism overhaul: 15-20 years. Total service life: 25-30 years with proper maintenance.

Q4: What payment terms do you accept?

A: First-time customers: 30% T/T advance, 70% before shipment. Established customers: 20% T/T + 80% against B/L copy. L/C at sight accepted.

Q5: Can the RMU MV HV Insulated Switchgear Panel with VCB be used at high altitude?

A: Standard design ≤2000m. High-altitude version (increased creepage, higher SF6 pressure) available for up to 3500m. Custom engineering for >3500m.