NXA-PAC-1100W-PE=: Cisco’s High-Efficiency 1100W AC Power Supply for Nexus Series Switches

Overview of the NXA-PAC-1100W-PE=

The ​​NXA-PAC-1100W-PE=​​ is a hot-swappable, 1100-watt AC power supply unit (PSU) designed for Cisco Nexus 9000 Series switches, including the Nexus 93180YC-FX and 9336C-FX2 platforms. Engineered for data centers and enterprise networks requiring high availability, this PSU delivers 94% efficiency (80 Plus Platinum-certified) while supporting advanced power redundancy and environmental monitoring.

Technical Specifications and Design Architecture

• ​​Input Voltage​​: 100–240 VAC (auto-sensing), 50/60 Hz, with inrush current limited to 40A.
• ​​Output​​: 1100W continuous power at 12V DC (91.6A max), compliant with ​​ERP Lot 9 2019​​ and ​​ENERGY STAR 3.0​​.
• ​​Efficiency​​: 94% at 50% load, 92% at 100% load (80 Plus Platinum standards).
• ​​Cooling​​: Dual counter-rotating fans with N+1 redundancy and ​​Thermal Coasting​​ to prevent airflow reversal during fan failure.
• ​​Compatibility​​: Nexus 9504/9508/9516 chassis and Nexus 9300-GX Series switches.

​​Key Features​​:

• ​​Digital PMBus Interface​​: Real-time monitoring of voltage, current, temperature, and fan speed via ​​Cisco NX-OS CLI​​ or ​​SNMPv3​​.
• ​​Dual Power Feeds​​: Accepts two independent AC sources for grid redundancy.
• ​​Environmental Resilience​​: Operates at -5°C to 55°C (ETS 300 019-2-4 Class 4.1) and withstands 95% non-condensing humidity.

Deployment Scenarios and Operational Benefits

1. High-Density Data Center Deployments

The PSU supports Nexus 9336C-FX2 switches with 36x 100G QSFP28 ports, ensuring stable power for full-load operation. A hyperscaler reported a 22% reduction in energy costs after replacing legacy 770W PSUs with NXA-PAC-1100W-PE= units (Cisco Energy Efficiency Report, 2023).

2. Mission-Critical Network Fabrics

In financial trading environments, the ​​N+1/N+N redundancy​​ configurations eliminate single points of failure. A stock exchange achieved 99.9999% uptime using dual PSUs with separate UPS feeds.

3. Edge Computing Sites

The PSU’s wide temperature tolerance (-5°C to 55°C) suits harsh environments like 5G MEC (Multi-Access Edge Computing) sites. A telecom operator deployed it in unmanaged cabinets across 200+ cell towers.

Addressing Critical User Concerns

Q: How does the PE= variant differ from standard 1100W PSUs?

​​A:​​ The ​​PE=​​ suffix denotes ​​Platinum Efficiency​​ certification and ​​Enhanced Environmental Monitoring​​, including predictive fan failure alerts and harmonic distortion analysis (<5% THD at full load).

Q: Can it operate in mixed PSU configurations?

​​A:​​ Yes, but Cisco recommends matching PSU models (e.g., NXA-PAC-1100W-PE= with NXA-PAC-1100W-PE=) to avoid efficiency imbalances. Mixed wattage PSUs may trigger ​​NX-OS power-invalid alerts​​.

Q: What happens during a brownout (voltage sag)?

​​A:​​ The PSU’s ​​Hold-Up Time​​ of 16 ms (at 100% load) ensures seamless failover to backup power sources without disrupting switch operations.

Procurement and Compatibility Guidance

For validated performance and warranty coverage, the ​​NXA-PAC-1100W-PE= is available here​​. Ensure chassis compatibility (e.g., Nexus 9508 requires 4x PSUs for N+N redundancy) and verify facility power circuits (20A minimum per PSU).

Operational Best Practices

• ​​Redundancy Configuration​​: Deploy in ​​Grid Redundant (N+N)​​ mode for dual AC feeds or ​​PSU Redundant (N+1)​​ for single-feed setups.
• ​​Firmware Updates​​: Upgrade PSU firmware via ​​Cisco FXOS​​ to patch vulnerabilities like CVE-2022-2097 (improper current limiting).
• ​​Thermal Management​​: Maintain ≥3 inches of clearance around air intakes and monitor inlet temps via ​​NX-OS “show environment power”​​.

Performance Benchmarks

• ​​Efficiency​​: 94.1% at 230V AC, 50% load (verified by TÜV Rheinland).
• ​​MTBF​​: 200,000 hours (calculated per Telcordia SR-332, Method 1 Case 3).
• ​​Noise Levels​​: 55 dBA at 25°C, 75% load (ANSI S12.10-2003 compliant).

Challenges and Mitigation Strategies

• ​​Harmonic Distortion​​: Use ​​Active Harmonic Correction​​ mode to reduce THD from 85% to <8% in aging power grids.
• ​​Fan Failures​​: Enable ​​Predictive Analytics​​ in Cisco DCNM to receive alerts 14 days before projected fan EOL.
• ​​Legacy Infrastructure​​: Install ​​Cisco RSP-2300-AC​​ PDUs to stabilize voltage for older facilities.

Final Perspective

The ​​NXA-PAC-1100W-PE=​​ exemplifies how power infrastructure can be both a liability and an asset. While many operators treat PSUs as commodity hardware, this unit’s telemetry capabilities and adaptive efficiency algorithms transform it into a strategic tool for sustainability and uptime. In an industry where every watt and every minute of downtime translates to financial impact, investing in intelligent power systems isn’t optional—it’s existential.