I need help with a control wiring circuit

Discussion in 'Homework Help' started by Antony, May 17, 2009.

  1. Antony

    Thread Starter New Member

    May 17, 2009
    Here's the summary:

    - A push button is used to start a supply fan (controller 1).
    - A return fan (controller 2) is interlocked to start automatically with the supply fan.
    - In the event of a smoke condition the fans shutdown automatically.
    - The supply and return fans cannot be restarted until the smoke detector system is reset (a latching relay is going to be used).
    - In the case of excessive smoke, an exhaust fan (controller 3) can be started but only if the smoke detector system has not been reset.

    A need to create a ladder and wire diagram.

    I'm having problems from the third step down.