Operation Manual

12
Diesel fuel flow sensor kit Installation and Operation Manual
NAVMAN
Date Weather Conditions
Vessel Sea State
Displacement
Load aboard
Gearbox ratio Passengers aboard
Engines Water Tanks
Fuel Tanks
Propeller
Max. Fuel Capacity
Working fuel capacity (max x 0.9)
Notes on filling out this table
Start at a slow speed. Allow a minute or two for
the boat to settle to its speed and trim and for
the display readings to stabilise. Then write the
displayed fuel flow(s) and boat speed in a line
of the table on the right, as described below.
Then increase the engine revs by another
100 or 200 rpm, wait a minute or two for the
readings to stabilise and repeat the readings.
Take readings up to the maximum service RPM
of your engine.
Column 1 - Engine RPM
Use the Navman tachometer reading if
possible, to be sure of accurate results. Write
the engine RPM in column 1.
Columns 2 and 3 - Fuel consumption
Units are litres or gallons - we presume you will
want to work in the units you are familiar with,
and that you have set-up the system display to
work in gallons or litres.
For a single engine boat, write the flow rate in
column 2. For a twin engine boat, write the port
engine flow rate in column 2 and the starboard
engine flow rate in column 3. The numbers for
each engine on a twin engine boat should be
very similar.
Column 4 - Total fuel flow rate
This is just the sum of the port and starboard
engine figures. Add together the flow rates
in column 2 and 3 and write the sum in
column 4.
Column 5 - Boat speed
Write the boat speed through the water in
column 5. Remember that speed through the
water is not the same as GPS speed if there
are any tidal or other currents.
Column 6 - Economy
If there is a speed instrument connected to the
display then this number can be read directly
for each rpm setting. Write the economy in
column 6. Otherwise, to calculate gallons
per nautical mile divide the consumption in
gallons/hr (column 4) by the speed in knots
(column 5); or to calculate Litres per nautical
mile divide the consumption in L/hour (column
4) by the speed in knots (column 5). Write the
answer in column 6.
Column 7 - range
This is for future reference. Note - please use
the range calculated as an indication, rather
than as a range that you know you can achieve.
For safety’s sake it is strongly recommended
that the calculation is done using 90% of the full
fuel capacity - that will leave 10% of the tank
as a reserve. Call this 90% value the working
capacity of the fuel tank. Also note that the
range would apply only in calm conditions
- difficult wind or sea conditions will drastically
reduce the distance you can go on a full tank.
A more heavily loaded boat will also have its
range reduced.
To get the maximum range for each engine
rpm setting, take the economy (the number
in column 6) and multiply it by the working
capacity of the fuel tank. Write the range in
column 7.
3-1 Fuel consumption table
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