Hello, I am working on a project that is needing a controller for a night purge system for a warehouse. The night purge system allows for free cooling at night by opening louvers and turning on an exhaust fan. The louvers and fan need to be controlled by controller that can initiate the night purge. The night purge sequence is as follows.

When the following conditions are true the night purge is ENABLED.

-the time is between 12am and 7am (this can be programmed into the controllers schedule)

- Outside air temperature is greater than 40 degrees F -The outside air temperature is less than 8 degrees F below the space temperature

-The inside air temperature is 65 degrees F

When the following conditions are met the controller is DISABLED.

-The inside air temperature is 55 degrees or below It looks like the only way for me to implement this sequence is to use ladder logic on a PLC.

Can I get some help as to what this ladder logic may look like? I also added so excel If statements that I made to help. A2 is inside temp and B2 is outside temp

=IF(AND(A2>65,B2>40),TRUE,FALSE)

=IF(NOT(A2-B2<=8),TRUE,FALSE)

=IF(NOT(A2<=55),TRUE,FALSE)

Time schedule

12am-7am

May-September