Honeywell 900RR0-0101 Redundant CPU Rack Assembly

Product Overview

The Honeywell 900RR0-0101 is a Redundant CPU Rack Assembly designed for the ControlEdge HC900 controller family. This specialized rack chassis houses dual redundant C75 CPUs and the Redundant Switch Module (RSM), providing a fault-tolerant controller foundation for high-availability process automation. Unlike standard I/O racks, the 900RR0-0101 is a dedicated controller rack with no local I/O slots, communicating with up to 12 remote I/O racks over Ethernet for distributed, scalable control architectures.

Key Features

• Dedicated redundant CPU rack — houses dual C75 CPUs and RSM
• No local I/O slots — controller rack is separate from I/O racks for clean architecture
• Supports dual independent power supplies — one per CPU for true power redundancy
• Communicates with up to 12 remote I/O racks via 100Base-T Ethernet
• Passive cooling design — no fans required, reducing maintenance
• High-grade aluminum construction for industrial durability
• Compact footprint: 137 × 261.6 × 151.7 mm
• Wide temperature tolerance for harsh industrial environments

Technical Specifications

• Model: 900RR0-0101
• Product Type: Redundant CPU Rack Assembly
• Series: ControlEdge HC900
• Rack Function: Dedicated redundant controller chassis
• CPU Capacity: 2 × redundant C75 CPUs (C70R compatible per configuration)
• RSM Slot: 1 × Redundant Switch Module (900RSM-0101 / 900RSM-0001)
• Local I/O Slots: None — I/O resides in separate remote racks
• Remote I/O Capacity: Up to 12 remote I/O racks via Ethernet
• Communication: 100Base-T Ethernet to remote racks and host systems
• Power Supply: Dual independent 900P01 / 900P24 power modules (one per CPU)
• Cooling Method: Passive (no fans)
• Construction: High-grade aluminum
• Dimensions (W × H × D): 261.6 × 137 × 151.7 mm (10.3" × 5.4" × 6.0")
• Weight: Approx. 1.75 kg (3.9 lbs)
• Operating Temperature: 0°C to +60°C
• Storage Temperature: −40°C to +85°C
• Humidity: 0% to 95% RH (non-condensing)
• Mounting: Panel or 19-inch rack mount compatible
• Certifications: CE, UL, CSA

Typical Applications

• High-availability redundant controller foundations
• Large-scale distributed control systems (DCS)
• Safety instrumented systems (SIS) with CPU redundancy
• Oil & gas central control room architectures
• Chemical plant and refinery process control

FAQ

Installation Guide

1. Mounting: Secure the 900RR0-0101 to a flat panel or 19-inch rack rail in the control cabinet. Ensure adequate clearance for airflow and module access.
2. CPU Installation: With power OFF, insert the two redundant CPUs into their designated slots. The RSM installs in the slot between them.
3. Power Supply Wiring: Install independent power modules for each CPU. Connect to separate power sources or UPS units for maximum availability.
4. Ethernet Networking: Connect the CPU Ethernet ports to industrial Ethernet switches using shielded CAT5e/CAT6 cable. Plan switch port capacity for up to 12 remote I/O rack connections plus host/operator interface links.
5. Grounding: Connect the rack chassis ground terminal to the cabinet earth bus using a minimum 4 mm² grounding conductor.
6. Commissioning: Power on and verify both CPUs and the RSM are recognized in the Hybrid Control Designer software. Perform a redundancy failover test to validate system integrity.

Selection Tips

• Select the 900RR0-0101 as the controller foundation for redundant HC900 architectures.
• Pair with two C75 CPUs and one 900RSM-0101 (or compatible RSM) for a complete redundant controller assembly.
• Plan remote I/O rack quantity (up to 12) and Ethernet switch port count during system design.
• Use fiber optic media converters if remote racks exceed 300 m from the controller.
• Verify whether your application requires the 900RR0-0101 or the newer 900RR0-0300 rack revision for latest CPU compatibility.