Tetra Tech Digital Systems designed and delivered a fully redundant chiller control system for a major Australian data center without disrupting operations.
A leading data center operator needed to upgrade an AE1 data center chiller control system in South Australia while keeping the live facility online. The existing system required higher availability, stronger fault tolerance, and clearer chiller performance visibility across the site. The upgrade also had to integrate multiple chillers and remote input/output (I/O) panels, maintain compatibility with existing plant and Schneider building management system (BMS) platforms, and follow strict client control philosophy and sequencing standards.
Our team designed and delivered a high-availability control architecture using redundant ControlLogix programmable logic controllers (PLC), dual redundant power supplies, and a Device Level Ring (DLR) network. We configured the main control panel with dual 230-volt alternating current (VAC) feeds and redundant 24-volt direct current (VDC) power supplies. The panel also housed ControlLogix 5580 processors and a human machine interface (HMI) using approved symbols and faceplates. The team integrated three remote Point I/O panels and four CompactLogix PLC panels, each managing individual chiller strings to site-specific sequencing standards.
Our engineers built, installed, and commissioned dedicated chiller control panels, integrated existing chillers into the Schneider BMS, and wired instrumentation back to chiller I/O panels. Triplicated I/O cards, temperature transmitters, Siemens magnetic (MAG) flow meters, and differential pressure transmitters improved monitoring and fault tolerance. Danfoss variable speed drives (VSD) enabled remote monitoring. The upgrade moved chiller sequencing from a single commercial controller to dual redundant industrial ControlLogix PLCs, removing a single point of failure and delivering zero downtime.
Benefits
- Completed major chiller plant upgrade with zero operational downtime
- Removed critical single point of failure through dual redundant ControlLogix PLCs
- Remote monitoring capability improved across all chiller assets