Plant Electrical Systems Upgrade & SCADA Installation

Plant Electrical Systems Upgrade & SCADA Installation

Location: Benton, Ill.

Client: Rend Lake Conservancy District

Completion Date: 2007

Burns & McDonnell completed design of a $4.6 million major renovation of the electrical power and SCADA systems for the 20 million gallon per day (MGD) Rend Lake Conservancy District water plant at Rend Lake, Ill. This project was designed in 2006.

The project consisted of two components. The first was an upgrade of the major electrical equipment. The second was design of a radio based telemetry and SCADA system. The existing plant was constructed in 1972 and has an average daily production of 13.2 MGD.

The work at the treatment plant consisted of relocating and replacing electrical switchgear, upgrading from 2400 to 4160 volt service, replacing variable frequency drives (VFD) and motors for the high service pumps and raw water pumps, and replacing the emergency generator. The work for the distribution system included design of a radio base telemetry system, upgrading remote site data and control features, upgrading remote site electrical components, and installing a distribution system control workstation.

The distribution system included a backup generator sized to support the entire plant electrical load. as well as handle any harmonic loading caused by the various VFDs being added to the plant. The automatic transfer switch system included protective relaying devices and a switch scheme coordinated with all utility requirements to allow safe operation of both the plant and utility.

The transfer switch equipment, as well as the main medium voltage distribution equipment, and the high service pump VFDs was designed on an existing concrete slab behind the main water plant building. The design includes a structure to provide weather protection for the new switchgear.

The high service pump motors were replaced with 4160 volt units.  The new high service pump VFDs were designed to be powered at 4160 volts from the new plant medium voltage distribution equipment. They were collocated with the medium voltage distribution equipment.

All other electrical equipment that currently operates at 2400 volts, such as various plant distribution transformers, must either be reconnectable at 4160 volts or be replaced.

All exterior medium voltage feeders were located underground. This includes the service from the utility substation to the main plant as well as the feed from the main plant to the intake structure.

The SCADA portion of the project included remote monitoring and some control of numerous pump stations, meters and tanks. The proposed system was designed to use radio telemetry signals to link the control room at the main water plant with the various field locations. CRTs or flat screen monitors were designed to replace the rows of instruments located in the existing plant control room. Continued operation of the existing equipment and a clean switch over to the new SCADA system were critical to the day-to-day operation of the water system.

Construction at the plant began in 2007. Burns & McDonnell is providing construction engineering work, site visits and limited construction inspection.