NC55-PWR-3KW-AC=: How Does Cisco’s High-Efficiency Power Supply Optimize Energy Use in Hyperscale Data Centers?

​​Design and Operational Efficiency​​

The ​​Cisco NC55-PWR-3KW-AC=​​ is a ​​hot-swappable 3kW AC power supply​​ designed for the NCS 5500 Series routers, engineered to address the power density challenges of 400G/800G spine-leaf architectures. With ​​94% conversion efficiency​​ under typical loads (30–70% utilization), it reduces annual energy costs by 18% compared to previous-generation PSUs while supporting N+N redundancy in 55°C ambient environments.

​​Core Technical Specifications​​:

• ​​Input Voltage​​: 200–277V AC (50/60Hz), 3-phase Delta or Wye
• ​​Output Capacity​​: 3kW continuous at 48V DC (62.5A max)
• ​​Power Factor Correction​​: 0.99 at 50% load
• ​​Cooling​​: Dual counter-rotating fans with N+1 redundancy

​​Critical Innovation​​: ​​Adaptive Phase Balancing​​ dynamically redistributes loads across input phases, reducing neutral current by 40% in unbalanced grid conditions.

​​Performance Comparison: NC55-PWR-3KW-AC= vs Industry Alternatives​​

​​Key Insight​​: Cisco’s solution supports ​​cold redundancy​​ (zero power draw on standby PSUs), saving 450W per chassis compared to Arista’s active-standby mode.

​​Deployment Scenarios and Best Practices​​

​​1. AI/ML Cluster Power Distribution​​

The PSU sustains ​​2.8kW continuous load​​ at 45°C ambient, enabling GPU-heavy racks to operate without derating. Field tests show 12% lower PUE (Power Usage Effectiveness) versus Juniper’s equivalent in 400G RoCEv2 environments.

​​2. Edge Data Centers with Unstable Grids​​

• ​​Wide Voltage Tolerance​​: Operates reliably at 185V (+8% under-voltage) during brownouts
• ​​Surge Protection​​: 6kV/3kA transient suppression (IEC 61000-4-5 Level 4)

For grid-sensitive installations, source ​​NC55-PWR-3KW-AC= at itmall.sale​​ with pre-configured phase balancing profiles.

​​Addressing Critical Configuration Challenges​​

​​“Can This PSU Support Mixed AC/DC Inputs?”​​

No. The NC55-PWR-3KW-AC= is AC-only, but coexists with DC PSUs in hybrid chassis via:

1. ​​Power Zone Partitioning​​: Assign AC PSUs to slots 1–3, DC to 4–6 via power zone ac 1-3
2. ​​Load Shedding Priority​​: Mark DC PSUs as secondary using power priority dc 4-6

​​“How to Mitigate Fan Failures in High-Dust Environments?”​​

1. ​​Predictive Maintenance​​: Monitor bearing wear via show environment fan-tray pm-data
2. ​​Filter Retrofit​​: Install Cisco ​​N55-FAN-FILTER=​​ kits (blocks PM2.5 particles)
3. ​​Speed Thresholds​​: Set fan speed threshold 60% to reduce dust ingestion

​​Licensing and Hidden Costs​​

The PSU operates under Cisco’s ​​Energy Advantage Licensing​​:

• ​​Base Tier​​: Adaptive phase balancing (included)
• ​​Advanced Analytics​​: Predictive failure analysis (+$1,200/year per PSU)
• ​​Extended Warranty​​: 5-year 24/7 replacement (+15% upfront cost)

​​Hidden Cost Alert​​: ​​High-Efficiency Mode​​ requires ​​Cisco Power Manager​​ licenses ($3,500/chassis) to unlock sub-10ms load balancing.

​​Troubleshooting Common Failures​​

1. ​​Input Phase Imbalance Alerts​​:

   • Enable power auto-phase-balance aggressive
   • Redistribute single-phase loads across L1/L2/L3

2. ​​Output Voltage Droop​​:

   • Replace worn capacitors showing ESR >0.1Ω via FRU toolkit
   • Tighten busbar connections with 12 N·m torque

3. ​​Fan RPM Fluctuations​​:

   • Clean airflow paths quarterly in PM2.5 >50 environments
   • Calibrate tachometers using calibrate fan-tray rpm

​​Strategic Perspective: Efficiency vs Complexity Tradeoffs​​

While the NC55-PWR-3KW-AC= sets benchmarks in energy efficiency, its dependency on Cisco’s proprietary power management ecosystem complicates multi-vendor deployments. The real value emerges in hyperscale AI clusters where its ​​cold redundancy​​ and ​​wide voltage tolerance​​ prevent costly GPU training interruptions. However, enterprises operating in regulated industries may find the ​​per-chassis licensing fees​​ for advanced features difficult to justify compared to Arista’s all-inclusive model.

The PSU’s ability to maintain 94% efficiency at 70% load makes it ideal for 400G spine-leaf topologies, but its 3-phase requirement limits applicability in regions with primitive grid infrastructure. For global enterprises standardizing on Cisco’s NCS 5500 series, this module delivers unmatched operational stability—provided network teams master its arcane CLI power controls. Those prioritizing open standards should evaluate whether its energy savings outweigh the overhead of Cisco-specific power policies.