Operating the exhaust fan
The full exhaust method is applied for places that do not need air conditioning but constantly need fresh air. If fresh air is required to enter the place where full exhaust is made, it is operated together with fresh air fans. Since there will be some pressure drop in places where full exhaust operation is performed with forced aspiration, the escaping of polluted air to other parts of the ship is prevented. Individual control panels (Figure.7) are provided for each exhaust fan (Figure.8).
When the fan start button is pressed, all air dampers automatically open 100% first. It turns off automatically at the end of the programmed time or when the smoke sensor is activated due to a possible fire in the air intake room.
The amount of exhaust is provided by a frequency-controlled electric motor. Any malfunction in the main components will appear in the alarm section while the exhaust fan is running. In such cases, the exhaust fan automatically stops and all dampers close 100%.
The running values of the exhaust fan, started after all the command elements on the panel are adjusted by Marine Engineer, must be monitored by means of control elements.
Figure.7 Exhaust fan control panel layout
Figure.8 Exhaust fan operation layout
Table.1 Setting and monitoring of exhaust fan command-and-control elements
Sq. Element Setting/Monitoring Condition
Control Monitor alarm bulbs lit WHITE
Control Monitor RST bulbs lit RED, GREEN, YELLOW
Control Monitor power bulb lits WHITE
Control Monitor outdoor air quality 85 %
Control Monitor indoor air quality 45 %
Command Set required air quality 85 %
Command Set fan start time 10:30
Command Set fan stop time 12:00
Command Shift control switch AUT
Control Monitor RAD position and lits OPEN, GREEN
Control Monitor EAD position and lits OPEN GREEN
Control Monitor FAD position and lits
Control Monitor MXD position and lits
Control Monitor CAD position and lits
Command Push Start button, lits GREEN
Control Monitor fan motor bulb lits GREEN
Control Monitor fan motor voltage 380 Volt
Control Monitor fan motor current 25 Amper
Control Monitor fan speed 200 RPM