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External Alert
The External Alert digital input is a level sensitive input. This digital input can be used to
alert a non-critical failure for equipment that is external to the Intelli-Hood system. If this
digital input is active, an “External Alert” message is displayed in the title on the main
screen on the Touchpad. This digital input does not affect fan speed.
Digital Output and 24VDC Output Status
The System Controller has two dry contact digital outputs and two 24VDC outputs. If the
digital output is active (“Energized”) then the dry contacts are closed or 24VDC is output
depending on the digital output. If the digital output is inactive (“De-Energized”) then the
dry contact is open or 0VDC is output depending on the digital output. The digital outputs
are driven based upon their configuration and the state of the associated Hood Groups.
The following is a short description of each digital output configuration option and how
the system state affects the digital output.
Temperature Alarm
Each Exhaust Hood has its own “Temperature Alarm Auto On” parameter which sets at
which temperature system should react to a Temperature Alarm. When a Temperature
Alarm occurs, all fans in the Hood Group turn on and run at full speed. A Temperature
Alarm digital output will be energized if an associated Hood Group is in a Temperature
Alarm state.
Smoke
A Smoke digital output can be used to detect when the fans are triggered to run full speed
due to optics being tripped. If the optics on an associated Hood Group detect effluent or
have a fault, then the Smoke digital output is energized.
Fan On
The Fan On digital output can be used to determine if fans are on or off for an associated
Hood Group. If any fan in an associated Hood Group is on, then the Fan On digital output
will be energized.
