Selection Recommendations Section
"Choosing the right switchgear saves more than just budget—it saves the O&M costs of the next decade."
1-1. High Voltage Switchgear Selection Guide(11kV/24kV/27kV/33kV/38kV/10kV/35kV)
Step 1:Clarify Basic Parameters (Customer Self-Check List)
| Parameter | Why It Matters | Common Pitfalls |
|---|
| Rated Voltage | Determines insulation level and cubicle dimensions | A 35kV project mistakenly selects a 12kV cubicle—scrapped outright |
| Rated Current | Determines busbar specifications and temperature rise | Select based on peak load, leave 20% margin |
| Short-Circuit Breaking Current | Determines circuit breaker capability | Ignoring maximum system short-circuit current—undersized selection can explode |
| Protection Degree | Determines cubicle sealing method | IP40 vs IP41, IP4X vs IP54—huge difference between outdoor/indoor |
| Operating Mechanism | Manual/motorized/spring | Unattended substations must be equipped with motorized + remote |
Step 2: Cubicle Type Quick Reference Table
| Application Scenario | Recommended Cubicle Type | Key Rationale |
|---|
| Urban Substation | KYN28A-12 | Withdrawable type, easy maintenance, mainstream application |
| Industrial & Mining Enterprises | XGN15-12 (Ring Main Unit) | Compact, low cost, maintenance-free |
| Data Center | Dual Power + Bus Tie Cubicle | Power supply continuity is top priority |
| Offshore Platform/Chemical | Fully Enclosed Gas-Insulated Cubicle (C-GIS) | Corrosion-resistant, explosion-proof, adapts to harsh environments |
⚠️ Three Common Misconceptions in Customer Selection
- Only looking at price, not short-circuit capacity — Cheap cubicles work in systems with small short-circuit currents, but once the system expands, it becomes a hidden danger
- Ignoring five-prevention interlocks — Inadequate mechanical interlocks lead to misoperation and direct injury
- Insufficient cable compartment space — During later capacity expansion, cables cannot be connected, forcing cubicle replacement
1‑2. Low Voltage Switchgear Selection Guide (0.4kV)
Core Selection Dimensions
Load Type → Determines choice of withdrawable/fixed partition/frame circuit breaker
├── Motor Load (frequent start/stop) → MCC Cubicle + Molded Case Circuit Breaker
├── Capacitor Compensation → Dedicated Reactive Power Compensation Cubicle
├── Lighting/Small Power → Fixed Partition Type is Sufficient
└── Main Incoming/Bus Tie → Air Circuit Breaker (ACB) + Intelligent Protection Unit
Cubicle Type Comparison Overview
| Cubicle Type | Applicable Scenario | Advantages | Limitations |
|---|
| GGD | Small factories, temporary power for infrastructure | Low price, simple structure | Average safety, inconvenient maintenance |
| GCK/GCS | Commercial buildings, medium-sized factories | Withdrawable, maintenance without power outage | Large depth, medium cost |
| MNS | Large-scale industry, data centers | Highest modularity, best safety | Relatively high price |
| BlokSeT/MDmax | High-end projects, foreign-funded factories | International brand quality, complete certifications | Long lead time, obvious premium |
Golden Rules of Selection
Rated current of main incoming cubicle circuit breaker ≥ 1.2× transformer rated current
Number of feeder cubicles = Actual number of circuits × 1.3 (reserve 30% spare circuits)
1‑3. Industry-Customized Selection Recommendations
| Industry | Special Requirements | Our Recommended Solution |
|---|
| New Energy PV/Wind | DC component, large harmonics | Add Active Power Filter (APF) + Dedicated surge protection module |
| Hospital/Data Center | Zero interruption | Dual power ATS + Bus tie auto-transfer & auto-recovery + Online monitoring |
| Metallurgy/Mining | Heavy dust, strong vibration | IP54 protection + Seismic design + Dust filter |
| Chemical/Petroleum | Explosion-proof, corrosion-proof | Explosion-proof certified cubicle + Positive pressure ventilation/sand-filled structure |
| Rail Transit | Limited space | Compact gas-insulated cubicle + Seismic brackets |