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Modular Building Institute

With Ethernet Switches, New BAS Helps Keep Efficiency Under Control

Dec. 29, 2006
Chicago building’s outdated DDC system replaced

In an effort to reduce energy, facilities-maintenance, and personnel costs, a plan to upgrade a 500,000-sq-ft building in downtown Chicago was implemented. A return on the investment was achieved by installing a dedicated building-automation network using Contemporary Controls’ industrial-grade Skorpion Ethernet switches, eliminating the structure’s hard-to-maintain, outdated direct digital-control system.

“The project involved complete facility management, including all HVAC-plant and terminal controls, lighting, access control, video, fire alarming monitoring, energy metering, and reporting employing Lon-Works, Modbus, BACnet, and SMTP protocols through HTTP,” Roland Gutknecht, director of customer service for Environmental Systems of Chicago, said. “After reviewing all its options, the customer decided on the Niagara Framework to monitor and control the system via BACnet over IP for the devices and systems. The framework is 100-percent open, a requirement that had to be met. In addition, more than 80 percent of the building’s motors were replaced, as well as converting to variable-frequency drives. This enabled a huge energy savings.” Gutknecht added that cooling and heating systems were updated, which resulted in more energy conservation.

These systems are joined into the building- automation system (BAS) so engineers can make essential repairs in the event of an alarm. In addition to e-mail alarming, Environmental Systems of Chicago implemented automatic fault detection- and-diagnostic rules to notify engineers of a deteriorating or energy wasting mode of operation among central-plant equipment.

The “Skorpion switches made the difference,” Gutknecht said. “They solved the problem. Our original switches did not support cascading, and there were many missed messages and packet losses. The Skorpion switches support cascading, but, more importantly, Contemporary Controls’ technical-support team tested our network architecture in their labs before deployment to ensure these devices would work.”

The compact EISK5-100T and EISK8-100T were employed. Using switching technology, the Skorpion 5 provides five 10/100-Mbps shielded RJ-45 ports, while the Skorpion 8 provides eight such ports. Each port supports the auto-negotiation protocol to select data rate, duplex, and flow control.

Gutknecht said the switches met specified needs, including reliability, ease of mounting and access, no wall-wart power supply, and low-voltage (8 to 24 v) AC power. The Ethernet network connects floors and areas of three remote sites through the Internet. Five IP-connected building automation controllers were added to support the various protocols.

Gutknecht said 64 areas of access (door security) are connected to the network with a central server and multiple operator interfaces for reporting. More than 30 cameras are attached to two digital video recorders (DVRs) that are viewed live over the network. The network, which is a combination local area network and wide area network, is supported via virtual-private-network (VPN) routers and firewalls.

The Skorpion switches are located on both ends of the VPN and firewalls, mounted within UL508A panels constructed by Environmental Systems of Chicago. Thirty-two switches network two servers, two printers, two workstations, the DVRs, 44 IP-connected access-control devices, and the five IP-connected building automation controllers. A combination of CAT5 and CAT6 copper wiring is employed, with segment lengths of less than 300 ft.

All of the systems, including the BAS, were centralized in the building’s engineering room so every facet of security, fire, and video can be monitored by one operator. In the event of an emergency, the operator can shut down an entire system, effectively securing the building. Environmental Systems of Chicago taught building engineers how to operate the equipment properly.

Information and photograph courtesy of Contemporary Controls.