Emergency Ventilation System
Background

Covering a service area of 5,325 square miles, NJ Transit is the nation’s third largest provider of bus, rail, and light rail transit. The agency operates a fleet of 2,027 buses, 711 trains, and 45 light rail vehicles. On 236 bus routes and 11 rail lines statewide, NJ Transit  provides nearly 223 million passenger trips each year.
Solution

ACC implemented the control and SCADA system for an emergency ventilation system controlling emergency fans, jet fans and dampers throughout the tunnels between five light rail stations. Operations interface with the system at the main operations center or the back up control center located adjacent to one of the stations.
Implementation

The system controls fans and jet fans in the following modes of Operation:

Normal– normal operational condition, fans are running, providing routine ventilation based on the time of year/season

Emergency– fire or smoke at one or more tunnel locations. The system automatically controls fans based on fire location and evacuation direction entered by the operator. This information is used to invoke the associated recipe or configuration controlling the fan, speed (high/low) and direction (supply/exhaust).

Manual– the operator manually controls fans and dampers
In addition, the system monitors the 4160/480 substations HVAC status. The ability to open/close each substation circuit breaker using the HMI is also provided. The system provides external diagnostic information on the system and power status for each site as well as central locations.

Key Features

  • The SCADA System includes redundant server nodes located at the main Operations Center and the backup control center. Client nodes are located at both locations.


  • Main Control Center Communications via Device Net. The equipment is controlled by five pairs of redundant Siemens S7-200 PLCs (one for each light rail station).

  • The PLCs communicate via Profibus to the Main Control Centers through a Pro/DeviceNet Converter. Other I/O is hardwired. Each light rail station also includes an LP. Communication between all sites and the SCADA system are on a fiber network.