ZN63(VS1)-12 Indoor Vacuum Circuit Breaker 12kV

The ZN63(VS1)-12 indoor vacuum circuit breaker is a highly reliable 12kV medium voltage switchgear component, widely used in power distribution systems for safe fault interruption and circuit protection. It is ideal for KYN28A-12 metal-clad switchgear, with both fixed and withdrawable (truck-mounted) options available.

🔧 Product Overview

ZN63(VS1)-12 is a three-phase, AC 50Hz indoor vacuum circuit breaker, designed for medium voltage applications. It features a spring-operated mechanism, high mechanical endurance, and arc-free switching capability using vacuum interrupters. This model supports frequent operation and rapid reclosing, making it suitable for industrial and utility networks.

Key Advantages:

Compact design for easy integration into 12kV switchgear
Arc quenching in vacuum: no gas, no pollution
Spring or electric operating mechanisms
Fixed-mounted and withdrawable versions
Long mechanical life (up to 10,000 operations)

📐 Technical Specifications

Parameter	Value
Rated Voltage	12 kV
Rated Frequency	50 Hz
Rated Current	630 A / 1250 A / 1600 A
Rated Short-Circuit Breaking	25 / 31.5 kA
Mechanical Life	≥ 10,000 operations
Operating Mechanism	Spring / Electric
Insulation Level (1 min)	42 kV
Lightning Impulse Withstand	75 kV
Mounting Type	Fixed / Withdrawable
Compliance Standard	IEC 62271-100

ZN63(VS1)-12 Indoor Vacuum Circuit Breaker 12kV

🌍 Typical Applications

12kV distribution networks
KYN28A-12 or HXGN series switchgear panels
Industrial motor control centers
Wind and solar power stations
Power plants, substations, and utilities

📊 Real Project Case

🔷 Ethiopia Substation Expansion Project (2023)
In 2023, 800+ ZN63(VS1)-12 VCBs were installed in metal-clad switchgear units across 14 substations in Ethiopia’s national grid upgrade.
Results:

Zero arc flash incidents reported during operation
Fully compatible with locally assembled KYN28A cabinets
Enabled over 5,000 successful auto-reclosing cycles without contact wear

Source: EEU Project Data Sheet, 2023

🛠 Installation and Maintenance

Position the breaker in the switchgear frame (fixed or withdrawable chassis);
Connect main terminals to busbars via standard plug-in or bolt connections;
Wire auxiliary circuits and control cables to the operating mechanism;
Perform a mechanical close-open test before energization.
Annual inspection recommended: check contact resistance, vacuum interrupter integrity, and mechanism lubrication.

❓ Frequently Asked Questions (FAQ)

1. What’s the difference between ZN63 and VS1?
They are the same product: “ZN63” is the standard designation, while “VS1” is the manufacturer’s model.

2. Is the breaker available as withdrawable?
Yes. The ZN63(VS1)-12 is offered as both fixed and truck-mounted for KYN28 switchgear.

3. How does vacuum arc extinguishing work?
The arc is quenched inside a sealed vacuum interrupter—no gas release, no external arc flash.

4. Can it support reclosing or frequent operation?
Absolutely. It is designed for load switching, capacitor bank operation, and up to 30 operations/day.

5. Does it comply with international standards?
Yes. Fully compliant with IEC 62271-100 and type-tested.