Furuno FI-3002, Operator'S Manual

Page: 11 / 16

10
3 Operation, Maintenance
3.1 How the Valve Works
The sensor incorporates a self-closing valve which minimizes the flow of water into the
vessel when the paddlewheel insert is removed. The curved flap valve is activated by
both a spring and water pressure. Water pushes the flap valve upward to block the
opening so there is no gush of water into the boat.
WARNING: The valve is not a watertight seal!
Always install the paddlewheel insert or the long blanking plug secured with the
retaining pin, safety rings, and safety wire for a watertight seal.
3.2 Using the Long Blanking Plug
To protect the paddlewheel, use the
long
blanking plug when the boat will be kept in
salt water for more than a week, the boat will be removed from the water, or aquatic
growth build-up on the paddlewheel is suspected due
to inaccurate readings from the instrument.
Warnin g: The O-rings must be intact and well lubricated to make a watertight seal.
1. Inspect the O-rings on the
long
blanking plug (replace if necessary) and lubricate
them with the silicone lubricant supplied or petroleum jelly (Vaseline ® ) (see
Figure 5).
2. Remove the paddlewheel insert from the housing by removing the safety wire, one
safety ring, and the retaining pin.
Do not remove the cap nut
(see Figure 2).
3. Grasp the pull ring and remove the paddlewheel insert with a slow pulling motion.
Note:
In the unlikely event that the paddlewheel insert cannot be removed, see
“Servicing the Valve Assembly” on page 4.
Warnin g: Always attach the safety wire to prevent the insert from backing out in
the unlikely event that the cap nut fails or is screwed on incorrectly.
4. Slide the
long
blanking plug into the housing with the arrows on the top pointing
forward toward the bow. Seat it into place with a pushing twisting motion until the
keys fit into the notches (see Figure 5). Secure it with the retaining pin, safety
rings, and safety wire (see Figure 2).
3.3 Servicing the Paddlewheel Insert
Aquatic growth can impede or freeze the paddlewheel’s rotation and
must
be removed.
Use a stiff brush or putty knife to remove the growth and clean the surface with mild
household detergent. If fouling is severe, push the paddlewheel shaft out using a spare
shaft or a 4D finish nail with a flattened point. Then, lightly wet sand the surface with
fine grade wet/dry paper. The water lubricated paddlewheel bearings have a life of up
to 5 years on low-speed boats [less than 10kn (11MPH)] and 1 year on high-speed
vessels. Paddlewheels can fracture and shafts can bend due to impact with water
borne objects and mishandling in boat yards. O-rings
must
be free of abrasions and
cuts to ensure a watertight seal. A replacement Paddlewheel Kit 33-113 is available.