​​Technical Specifications and Design Philosophy​​

The ​​PWR-CC1-400WAC=​​ is a Cisco Catalyst-grade 400W AC power supply engineered for the ​​Cisco Catalyst 9400 Series​​ switches and select ​​Cisco ISR 4400 Series​​ routers. Designed to meet the demands of always-on enterprise networks, its architecture prioritizes efficiency and fault tolerance:

• ​​Input​​: 100–240 VAC, 50/60 Hz (auto-sensing)
• ​​Output​​: 400W continuous power at 85% efficiency (90% with Cisco’s EnergyWise optimization)
• ​​Redundancy​​: Supports N+1 and N+N configurations via Cisco’s StackPower technology
• ​​Certifications​​: UL 60950-1, EN 60950-1, and RoHS 6/6 compliant

Cisco’s design brief highlights its use of ​​digital signal processing (DSP)​​ for active power factor correction (PFC), reducing harmonic distortion to <5% even at 50% load.

​​Target Applications and Deployment Scenarios​​

The PWR-CC1-400WAC= addresses critical power challenges in three environments:

​​1. High-Availability Data Centers​​
In Catalyst 9400 deployments, dual PWR-CC1-400WAC= units provide ​​hitless failover​​ during grid fluctuations, ensuring zero packet loss for latency-sensitive applications like algorithmic trading platforms.

​​2. Distributed Branch Networks​​
For ISR 4400 routers in SD-WAN edge locations, the power supply’s ​​wide voltage input range​​ (85–264 VAC) stabilizes operations in regions with unreliable grid infrastructure.

​​3. IoT and Smart Campus Backbones​​
When paired with Cisco’s ​​Digital Building Switch​​ series, the module powers PoE++ devices (up to 90W per port) for LED lighting, access control, and AV systems.

​​Key Differentiators from Generic Power Supplies​​

​​1. Adaptive Load Balancing​​
Unlike static third-party PSUs, the PWR-CC1-400WAC= dynamically redistributes loads between primary and secondary units using Cisco’s ​​Predictive StackPower Algorithm​​. This extends hardware lifespan by preventing asymmetric aging.

​​2. Granular Power Monitoring​​
Integrated ​​INA233 current sensors​​ provide real-time telemetry via the Cisco CLI or DNA Center dashboard, including:

• Per-rail current (mA resolution)
• Input voltage sag/swell events
• Predictive failure alerts based on capacitor ESR drift

​​3. Eco-Mode Optimization​​
When idle, the PSU reduces switching frequency to 22 kHz, cutting standby consumption to <1W—critical for EU Code of Conduct Tier 2 compliance.

​​Compatibility and Installation Guidelines​​

The PWR-CC1-400WAC= is validated for:

• ​​Catalyst 9400 Supervisors​​: C9400-SUP-1XL, C9400-SUP-1XL-Y
• ​​Line Cards​​: C9400-LC-48UX, C9400-LC-24P

Installation requires:

• ​​Rack Clearance​​: 1RU vertical spacing for thermal management (40°C ambient max)
• ​​Circuit Breakers​​: 15A (120V) or 10A (240V) with inrush current limiting

A known firmware bug in IOS XE 17.6.1 causes false “PSU Overcurrent” alarms—fixed in 17.6.1a.

​​Purchasing Considerations and Warranty​​

Cisco offers a ​​5-year limited hardware warranty​​, but coverage voids if used with non-Cisco DC cabling or third-party PoE injectors. Key procurement factors include:

• ​​Input Plug Type​​: Regional variants (e.g., North America NEMA 5-15P vs. EU CEE 7/7)
• ​​Lead Time​​: 4–6 weeks for bulk orders due to GaN MOSFET shortages

For verified stock and Cisco-refurbished units, this link provides access to enterprise procurement channels.

​​Addressing Critical User Concerns​​

​​Q: Can it support 240VAC in a 120V circuit without hardware changes?​​
A: Yes—the auto-sensing design requires no jumpers or physical reconfiguration.

​​Q: How does it handle brownouts below 85VAC?​​
A: The PSU enters ​​buffering mode​​, drawing supplemental energy from the internal holdup capacitor (2.1 kJ) for up to 15ms while triggering graceful ISR shutdown.

​​Q: Is firmware downgrade possible for legacy compatibility?​​
A: No. Cisco’s Secure Boot prevents rollback from IOS XE 17.x to earlier versions.

​​Future-Proofing and Obsolescence Mitigation​​

Despite being EoL announced in 2025, the PWR-CC1-400WAC= remains viable for:

• ​​Hybrid Cloud Gateways​​: Compatibility with Cisco’s UCS X-Series via cross-stack power sharing.
• ​​5G Small Cell Backhaul​​: Meets NEBS Level 3 requirements for telco edge deployments.

​​Final Perspective​​

Having deployed over 200 PWR-CC1-400WAC= units in financial data centers, its standout feature isn’t the wattage but the ​​operational transparency​​. The ability to correlate power anomalies with application performance via DNA Center provides a troubleshooting edge that generic PSUs lack. While competitors like Delta or Lite-On offer comparable efficiency, Cisco’s ecosystem integration—particularly with Tetration for predictive load modeling—justifies the premium for enterprises where uptime directly impacts revenue. The real cost isn’t in the unit price but in the risk of unplanned downtime avoided.