J.P. Instruments Fuel Scan 450 Installation Manual - Manual (Page 13)

J.P.Instruments Fuel Flow Installation Manual
Report # 400
FS-450 Page 13 of 16
Rev A : Date 02/1/2002
 Check that the instrument make and model are correct before starting the installation (check the markings
on the side of the instrument). A gravity feed system requires an PN 700900-2 flow transducer (marked
"231" on top). A carbureted engine with a fuel return line requires two transducers at additional cost
 If this instrument is to replace an existing unit in the aircraft, it is the installer's responsibility to move or
replace any existing instruments or components in accordance with FAA approved methods and proce-
dures. The following Installation Instructions do not cover moving or the removal of any existing
instruments or components.
 Before connecting any hoses to the transducer, thoroughly clean them and insure they are free of any
loose material. Never pass high pressure air through or blow through the transducer, damage will
occur.
 Remove the transducer cap plugs when ready to install hoses. Do not use aluminum fittings with the fuel
flow transducer or Gauling may occur.
 The inlet and outlet ports of the transducer have ¼ NPT threads. When assembling fittings into the inlet
and outlet Do Not Exceed a torque of 15 ft. lbs. Or screw the fittings in more than 2 full turns past hand
tight.
 A screen or filter should be installed upstream of the transducer. As turbulence upstream of the
transducer affects it’s performance, there should be a reasonable length of straight line between the
transducer inlet.
 Install the transducer with the wires leads UP to vent bubbles and insure that the rotor is totally immersed
in fluid.
 Note the direction of fuel flow marked on the transducer. Fuel must flow in this direction.
 Note and record the K-factor engraved in the side of the transducer and also on the white tag attached to
the transducer. Most transducers have a K- factor of 29.90.
10. System Checkout: Check instrument operation as follows:
 Turn the aircraft master switch on (engine off). Tap the step switch until 0 GPH is displayed. Turn the
boost pump on for a few seconds. The display should indicate 3 to 8 GPH.. A problem at this step could
be caused by poor connections on the red or black power and ground leads.
 A reading of “ --- “ dashes indicate no fuel flow transducer signals. A problem at this step could be caused
by a poor connection or crossed flow transducer wires.
 With the engine running, check the "FLOW" Display to read properly.
 After running the engine, check the fuel hoses, transducers and fittings for leaks.