ABB CPD 11 Redundant Power Supply Rack

The ABB CPD 11 redundant power supply rack is a mechanical and electrical assembly designed to house two independent power supply modules, providing a redundant power source for ABB control systems, particularly within the Symphony Plus and earlier Symphony families. This rack ensures high availability by allowing one power supply to instantly take over the full load should the other fail, without any interruption to the powered equipment.

Redundancy Architecture

The CPD 11 accommodates two identical or compatible power supply modules (such as those from the SPS series) in a primary/standby configuration. Both modules are connected to the input AC or DC source and their outputs are diode-ORed within the rack to combine power while preventing reverse current. In normal operation, both modules share the load; if one fails, the other immediately supplies the full current. The rack includes monitoring circuitry that provides alarm signals (via relay contacts) for loss of one supply, ensuring that maintenance can be scheduled without shutting down the system.

Mechanical Design and Mounting

The rack is constructed from rugged metal and designed for installation in standard 19-inch cabinets or on a panel. It typically occupies 3U of vertical space and includes guides for easy insertion and removal of power modules. The backplane provides all necessary connections: input power terminals, output distribution bus, and alarm wiring. The rack also features a protective cover over the high-voltage areas for operator safety.

Electrical Specifications

• Input voltage range: Compatible with the inserted power modules (e.g., 100-240V AC or 125/250V DC).

• Output voltage: 24V DC (or as per modules) with total current up to 40 A (depending on module rating).

• Redundancy mode: N+1 with automatic switchover.

• Alarm outputs: Form C relay contacts for fail and warning signals.

• Operating temperature: -20°C to +60°C.

• Dimensions (HxWxD): 133 x 483 x 200 mm (typical).

Integration with ABB Control Systems

The CPD 11 is specifically designed for use with ABB's distributed control systems (DCS) and programmable logic controllers (PLC). It mounts in the same cabinet as controllers and I/O modules, distributing redundant 24V DC power via the system backplane or external wiring. The rack's alarm outputs can be connected to a digital input module to notify the control system of power supply status, enabling proactive maintenance.

Hot-Swap Capability

Both power modules are hot-swappable, meaning they can be replaced while the system remains powered. The CPD 11 rack includes keying and retention mechanisms to ensure correct insertion. This feature drastically reduces downtime during power supply maintenance or upgrades.

Applications

• Powering critical controllers and I/O in power generation plants.

• Redundant power for safety systems and emergency shutdown (ESD).

• Industrial automation where continuous process operation is essential.

• Substation automation and telecontrol equipment.

Reliability and Compliance

The CPD 11 rack is built to meet industrial standards for vibration, shock, and electromagnetic compatibility (IEC 61000). It carries CE marking and UL recognition when used with approved power modules. The use of redundant supplies significantly increases overall system MTBF.

With its robust construction and seamless redundancy, the ABB CPD 11 redundant power supply rack is a key component for achieving high availability in mission-critical automation environments.