Alcatel-Lucent 3HE00272DB 7750 SR-7 DC Chassis with PEM3+EFT

The Alcatel‑Lucent 3HE00272DB is a DC‑powered 7‑slot chassis for the 7750 SR‑7 service router, featuring the PEM3+EFT power entry module and enhanced fault tolerance (EFT). This platform is the physical foundation for building carrier‑grade IP/MPLS networks that require high availability, scalability, and deterministic performance. The 7750 SR‑7 is designed for service provider core, edge, and aggregation deployments, as well as large enterprise WAN environments.

Overview

The 7750 SR‑7 chassis provides seven slot positions that can accommodate a mix of I/O modules, switch fabric modules (SFMs), and control processor modules (CPMs). The DC power configuration includes redundant, hot‑swappable power entry modules (PEM3) that convert ‑48 VDC input to the voltages required by the system. The EFT (Enhanced Fault Tolerance) feature adds additional protection against power disturbances, over‑voltage, and current surges, ensuring continuous operation even in harsh electrical environments.

Key Features

• 7‑slot modular chassis supporting I/O, fabric, and control modules

• DC input: ‑48 VDC to ‑60 VDC, with dual feed redundancy

• PEM3+EFT power entry modules with surge suppression and transient protection

• Hot‑swappable fans, power supplies, and all field‑replaceable units

• High‑speed backplane with 2.4 Tbps switching capacity when fully populated with SFM5

• Front‑to‑back cooling with multiple fan trays for optimum thermal management

• Alarm and status LEDs for rapid fault isolation

• Compliance with NEBS Level 3 and ETSI standards

Technical Specifications

• Chassis Slots: 7 (including 2 control slots, 5 I/O slots, or flexible assignment)

• Power Input: ‑48 VDC to ‑60 VDC, 20 A per feed (dual feeds)

• Power Supply Modules: PEM3+EFT, 1200 W each, N+N redundancy

• Cooling: Three fan trays with variable speed fans

• Dimensions: 444.5 mm (H) × 482.6 mm (W) × 546 mm (D) – 10U rackmount

• Weight: 25.4 kg (empty chassis) / 35.5 kg (fully loaded)

• Operating Temperature: 0°C to 45°C

• Storage Temperature: -40°C to 70°C

Applications

This DC‑powered chassis is ideal for central office, data center, and remote site deployments where DC power is standard. The 7750 SR‑7 is used for IP/MPLS core routing, business VPN services, mobile backhaul aggregation, and metro Ethernet transport. Its compact 7‑slot form factor provides a balance between port density and physical space, making it suitable for both large and medium‑sized network nodes.

Compatibility

The 3HE00272DB chassis supports all 7750 SR‑series line cards, SFM5‑7 switching modules, and CPM7 or CPM5 control modules. The PEM3+EFT power modules are specifically designed for this DC variant; they are not interchangeable with AC power modules. The chassis backplane is compatible with the latest SR OS software releases, enabling features like Segment Routing, EVPN, and SR‑TE.

Installation and Maintenance

Installation requires standard 19‑inch rack mounting, with grounding and DC power connections made to the PEM3 terminals. The chassis includes a ground stud and protection against reverse polarity. Routine maintenance includes checking fan operation, air filters, and power supply status via the front panel LEDs or remote monitoring. The modular design allows for field upgrades and repairs without taking the entire chassis out of service.

Conclusion

The Alcatel‑Lucent 3HE00272DB 7750 SR‑7 DC chassis with PEM3+EFT provides a rugged, high‑availability foundation for next‑generation IP/MPLS networks. Its robust power design, NEBS compliance, and flexible slot architecture enable service providers to meet demanding reliability and performance requirements while simplifying operations and reducing total cost of ownership.