Distributed digital control system in the Washington Mutual Center.
Debra Biela,
Marketing and Communications Specialist, Contemporary Controls
Among cities that stand out for their own architectural style, Seattle, Washington, is a clear leader thanks to the construction of the 42-story Washington Mutual Center and the Seattle Art Museum in its downtown area.
Its contemporary architectural style is as unique as the Alerton distributed digital control and monitoring system installed in it, which serves as the hub for integrating all the systems operating in the building.
The building was built through a joint venture between Washington Mutual Bank (WAMU) and the Seattle Art Museum (SAM).
As a result, the museum gained 300,000 square feet of additional space (12 full or partial floors), and WAMU's office space increased by 900,000 square feet. In addition, underneath the office building is a 6-story parking structure capable of accommodating over 700 cars.
When the project began in 2004, ATS Automation, Inc. of Seattle offered its expertise as a control system installer to ensure optimal operation of the building's management system. ATS used an Alerton distributed digital control system, installing it in WAMU's portion of the building and using it as the central element to integrate the entire building's management system.
“What makes this project unique is the smoke detection and control system it uses,” said Pete Segall, senior sales engineer for ATS. “Most buildings do not have a distributed digital control system to handle smoke detection and control. These functions are often handled by fire alarm systems.”
As Segall explained, the goal of the project was to address the need to develop a control system that could monitor and control the operation of heating, ventilation and air conditioning (HVAC) systems, smoke detection and control systems, and combination systems that combine all of the above functions, both during routine operation and during emergency situations.Dedicated smoke control systems do not operate on a day-to-day basis; unlike HVAC and combination systems, firefighters can manually control smoke control and combination systems using a dedicated control panel that is connected to the network. Such control panels allow manual control of smoke control systems to remove smoke from floors and regulate air pressure on them.”
The following systems are integrated into the Alerton solution:
Heating, Ventilation, and Air Conditioning System– Alerton Direct Digital Control (DDC) system.
Smoke Detection and Control System – Alerton Direct Distributed Digital Control system.
Automatic Transfer Switches – Modbus Integration.
Emergency Generators – Modbus Integration.
Variable Frequency Converters – BACnet MS/TP Integration.
Chillers – BACnet Ethernet Integration.
EST Fire Alarm – Field Server Driver.
Power Consumption Monitoring SystemSiemens (WAMU) – Modbus Integration.
Lighting Control System Lutron – BACnet Ethernet Integration.
In short, UL 864 is a system designed to detect and control smoke in buildings. Since the entire control system (which uses an Ethernet local area network) requires switches, ATS used Ethernet switches from Contemporary Controls, a Downers Grove, Illinois, company with a proven track record in industrial networking equipment. These switches have eight ports that are used during testing, making them UL Listed.
The EIS8-100T switches undergo rigorous component testing to achieve the necessary certification for UL Listing of systems based on them. Ethernet switches must comply with UL 864 to meet the requirements of NFPA 72, which requires that any communications path used to transmit life-critical information must be suitable for transmitting fire alarm signals.
These copper switches were required to meet all of the requirements of UL 864.
They were subjected to the following high-voltage tests:
Supply line surges
– 6000 V.
Signal line surges
– 2400 V.
Input surges
– 5000 V.
Overvoltage
– 115% of the nominal value.
These switches have passed all the above tests and should withstand any voltage changes that occur on the signal and power lines and continue to function normally. They should withstand special temperature and humidity conditions (temperature 50 ° C and humidity 95%) for 24 hours.
The design of the system must remain constant. Any changes made to the equipment require retesting of the system. To ensure the quality and reliability of the systems it builds, Segall said, ATS uses Contemporary Controls equipment that provides the appropriate level of reliability.
In addition, Contemporary Controls strives to obtain and maintain UL 864 certification for its Ethernet switches and provide the necessary qualified technical support.
The EIS8-100T switches feature 10/100 Mbps ports using RJ-45 connectors. These switches are capable of operating over a wide range of AC and DC voltages. In addition, the switches must consistently meet certain criteria, including reliability, that are key to their performance in smoke detection and control systems.
Two Ethernet switches are physically connected to the Alerton Smoke Detection and Control System's BACnet/Ethernet network using CAT 5 cabling, allowing for precise distributed digital control logic. The switches were wired together, allowing the signal wires to be shorter than the 225-foot limit for such networks.
One of the switches served as a «gateway» for the non-smoke detection and control logic of the global distributed digital control system and for the Building Management System computer (the user interface for the system).
These switches are mounted in wall-mounted cabinets that also meet UL specifications for use in fire protection systems.
One of these switches was installed in the central fire control room and the other was installed in the telecommunications room on the lower two levels of the Washington Mutual Center.
As Segall said, the building's system is fully BACnet compliant — both at the Ethernet and MS/TP network levels. The system includes two Ethernet networks — a BACnet UL 864/Ethernet network and a standard BACnet/Ethernet network.
Alerton controllers are installed on both Ethernet networks for global control of the system. The next level up is the MS/TP network. Wire lengths on UL 864 networks must not exceed 225 feet. Wire lengths on other Ethernet networks can be anywhere from 100 feet to 300 feet.
According to Segall, using the BACnet protocol is important here.
The protocol is open, uses standard networking technologies such as Ethernet LANs, is continually updated by ASHRAE, and is constantly evolving as new technologies are developed. In addition, there are a large number of third-party systems that can be integrated into BACnet-compliant systems because of its open nature. “When it comes to the Ethernet network, it’s the backbone of our entire system,” Segall said. “It allows for high-speed, high-volume data transfers across the system.”
The biggest benefit for those involved in the day-to-day management of the facility is the ability to collect information using The Alerton Envision system, designed to be used in conjunction with the BACtalk software package. For example, information on the status of equipment in the smoke detection and control system can be obtained. “The Envision system is a window into all the other systems,” Segal said.
“The Envision software allows building staff to visualize all the information in the system using floor plans, text tables, charts, graphs, etc. It also allows trend charting, alerting, custom validation, custom user interfaces, and more.”
Segall concluded, “The Washington Mutual Center project utilized products from a variety of hardware manufacturers and systems integration companies to achieve optimal system performance.”
Based on materials from AutomatedBuildings