Sjekket nå og den eksterne pumpa er en del av kretsløpet i følge tegningene i verkstedhåndboka.
Her er hva verkstedhåndboka skriver om funksjonen. Kan sende hele på pdf hvis du sender meg pm.
Once initiated by a message from the ATC module, FF operation is controlled by the control module in the FF unit. The control module controls the FF unit at one of two heat output levels, 2.5 kW at part load combustion and 5 kW at full load combustion.
Start Sequence: At the beginning of the start sequence the control module energizes the glow plug function of the glow plug/flame sensor, to preheat the combustion chamber, starts the combustion air fan at slow speed and energizes the coolant circulation pump. After appro imately 30 seconds, the control module energizes the FF fuel pump at the starting sequence speed. The fuel delivered by the FF fuel pump evaporates in the combustion chamber, mi es with air from the combustion air fan and is ignited by the glow plug/flame sensor. The control module then progressively increases the speed of the FF fuel pump and the combustion air fan. Once combustion is established the control module switches the glow plug/flame sensor from the glow plug function to the flame sensing function to monitor combustion. From the beginning of the start sequence to stable combustion takes appro imately 90 seconds for a start to part load combustion and 150 seconds for a start to full load combustion.
Coolant Temperature Control: When the control module first enters the active mode, it initiates a start to full load combustion. Full load combustion continues until the heat e changer casing temperature reaches 72 C (162 F), at this point the control module decreases the speed of the FF fuel pump and the combustion air fan to half speed, to produce part load combustion. The control module maintains part load combustion while the heat e changer casing temperature remains between 68 and 76 C (154 and 169 F). If the heat e changer casing temperature decreases to 68 C (154 F), the control module switches the system to full load combustion again. If the heat e changer casing temperature increases to 76 C (169 F), the control module enters a control idle phase of operation.
On entering the control idle phase, the control module immediately switches the FF fuel pump off, to stop combustion, and starts a timer for the combustion air fan. After a 2 minute shutdown period, the control module switches the combustion air fan off and then remains in the control idle phase while the heat e changer casing temperature remains above 71 C (160 F). If the heat e changer casing temperature decreases to 71 C (160 F), within 15 minutes of the control module entering the control idle phase, the control module initiates a start to part load combustion. If more than 15 minutes elapse before the heat e changer casing temperature decreases to 71 C (160 F), the control module initiates a start to full load combustion.
In order to limit the build up of carbon deposits on the glow plug/flame sensor, the control module also enters the control idle phase if the continuous part and/or full load combustion time e ceeds 72 minutes. After the shutdown period, if the heat e changer casing is still in the temperature range that requires additional heat, the control module initiates an immediate restart to part or full load combustion as appropriate.
Shutdown: When the ATC module sends a bus message to de-activate the FF operation, the control module de-energizes the FF fuel pump to stop combustion, but continues operation of the combustion air fan and the circulation pump to shutdown the FF unit. The shutdown time depends on the combustion load at the time the message is received.