ROCKWILL 12kV MV Switchgear Solution: Reliable Power Control with Minimized Downtime

ROCKWILL

06/12/2025

1. Solution Overview

Product: KYN28 Indoor Metal-Clad Withdrawable Switchgear
Voltage: 3.6kV, 7.2kV, 12kV, or 24kV (Select based on system voltage)
Application: Power plant distribution, substation receiving/transmission, industrial plant power distribution, large HV motor starting.
Key Advantage: Centralized draw-out design for partial de-energization during maintenance, minimizing downtime.

2. Core Technical Specifications

Parameter	Value
Rated Voltage (kV)	3.6 / 7.2 / 12 / 24
Rated Frequency (Hz)	50 / 60
Rated Current (A)	630 / 1250 / 1600 / 2000 / 2500 / 3150 / 4000
Rated Short-Circuit Breaking Current (kA)	20 / 25 / 31.5 / 40
Rated Short-Time Withstand Current (4s) (kA)	20 / 25 / 31.5 / 40
Power Frequency Withstand (1 min)	Dry: 34-65kV (varies by voltage) Wet: 28-50kV (varies by voltage)
Lightning Impulse Withstand (kV)	75-125kV (varies by voltage)
Protection Class (Housing)	IP4X
Ambient Temperature	-15°C to +40°C
Max. Installation Altitude	1000m
Mechanical Life (Circuit Breaker)	VS1/VD4: 10,000 ops VSM: 100,000 ops

3. Key Design Features

Armored Compartmentalization: Four fully segregated metal compartments (Busbar, Breaker, Cable, Instrumentation) for enhanced safety (IEC 298 / GB 3906-91 compliant).
Centralized Draw-Out: Breaker (e.g., VD4, VS1, 3AH3) mounted on a withdrawable truck. Enables "hot" busbar maintenance without full system shutdown.
Modular & Flexible: Standard widths (800mm/1000mm) allow easy combination of functional units (incomer, feeder, metering, PT).
Special CT Design: Facilitates front-end wall-mounting and maintenance access.
High-Performance Components: Superior insulating materials & conductive elements ensure stability under fault conditions.
Compatibility: Supports major vacuum breakers (VS1, ABB VD4, Siemens 3AH3, GE VB2, ROCKWILL VSM).

4. Physical Layout & Dimensions

(Select based on Rated Current & Configuration)

Cabinet Width (A)	Depth (B) (mm)	Height (mm)	Typical Weight (kg)	Recommended Use Case
650 mm	1400 mm	2200 mm	700	<1250A, Compound Insulation, Front Cable Access
800 mm	1500 mm	2200 mm	800	<1250A, Air Insulation, Front Cable Access
800 mm	1600 mm	2200 mm	900	<1250A, Rear Overhead Line
1000 mm	1500 mm	2200 mm	1100	>1250A, Front Cable Access
1000 mm	1600 mm	2200 mm	1200	>1250A, Rear Overhead Line
900 mm	1700 mm	2200 mm	1000	Specific config (e.g., with Siemens 3AH5)

Note: Height may reduce to 1660mm for 1000mm wide cabinets with rear overhead lines >1600A.

5. Component Selection

Instrumentation: Special CTs for front access, VTs, surge arresters, relay protection devices (overload, short-circuit, earth fault).
Busbars: Main & branch busbars rated equal to circuit current.
Earthing: Integral earthing switch.

6. Implementation & Service

Specification: Define voltage, current, SC rating, breaker type, and layout (front/rear cable access).
Customization: ROCKWILL provides tailored solutions (design, assembly, testing).
Installation: Requires stable environment (<1000m, -15°C to +40°C, <95% humidity). No corrosive gases/vibration.
Commissioning: Functional & safety checks per IEC/GB standards.
Maintenance: Utilize draw-out feature for partial de-energization. Minimal maintenance due to robust design.
After-Sales Support:

7. Why Choose This Solution?

Safety: Segregated compartments, front-access CTs, compliance with IEC/GB/DL standards.
Reliability: High-quality components, proven design, comprehensive testing.
Minimal Downtime: Draw-out breaker enables partial maintenance without shutdown.
Flexibility: Modular design simplifies expansion/modification.
Global Support: ROCKWILL’s 20+ years of expertise and direct technical support