U.S. Patent 6,426,918; 6,671,225; 6,678,208. EP 1 634 087
Follow the precautions below for optimal product
performance and to reduce the risk of property
damage, personal injury, and/or death.
WARNING: Always wear safety goggles and a dust
17-259-01 rev. 0204/12/11
mask when installing.
WARNING: The power must be ‘OFF’ before proceeding.
WARNING: The power supply voltage must be
WARNING: A safe installation requires a 0.5 amp fast
blow fuse or circuit breaker.
WARNING: The valve is not a watertight seal! Always
install the ultrasonic insert or the long blanking plug
secured with the retaining pin, safety rings, and safety
wire for a watertight seal.
WARNING: The o-rings must be intact and well
lubricated to make a watertight seal.
WARNING: Always attach the safety wire to prevent
the insert or blanking plug from backing out in the
unlikely event that the cap nut fails or is screwed on
incorrectly.
WARNING: Immediately check for leaks when the
boat is placed in the water. Do not leave the boat
unchecked for more than three hours. Even a small
leak may allow considerable water to accumulate.
WARNING: When the valve assembly is removed,
always insert the short emergency plug with the cap
nut secured with the safety wire for a watertight seal.
CAUTION: Never pull, carry, or hold the transducer by
its cable; this may sever internal connections.
CAUTION: Never use a fairing with a plastic housing;
the protruding sensor would be vulnerable to damage
from impact.
10-15VDC
Record the information found on the cable tag for future reference.
Part No._________________Date___________
Applications
• Not recommended for boats designed to pull air under the hull.
• Plastic housing recommended for fiberglass or metal hull only.
Never install a plastic housing in a wood hull since swelling of
the wood may fracture the plastic.
• Bronze housing recommended for fiberglass or wood hull only.
Never install a bronze housing in a metal hull because
electrolytic corrosion will occur.
How the Ultrasonic Speed Sensor Works
The speed sensor uses ultrasonic pulses to collect echoes from
small particles in the water as they pass under two transducers
embedded in the insert (see Figure 1). These transducers monitor
the particles in their respective beams. As the boat travels through
the water, both transducers ‘view’ the same stream of particles.
Because it takes time for particles to travel between the two
transducers, the aft transducer detects the particles later than
does the fore transducer. By measuring this time lapse, the
instrument calculates the boat speed. If the boat is airborne, even
for a short time, or in highly aerated water, the sensor will
measure an incorrect speed.
Tools & Materials
Safety goggles
Dust mask
Water-based anti-fouling paint (mandatory in salt water)
Electric drill with 10mm (3/8") or larger chuck capacity
Drill bit3mm or 1/8"
Hole saw51mm or 2"
Sandpaper
CAUTION: Never install a metal housing on a vessel
with a positive ground system.
CAUTION: Never use solvents. Cleaners, fuel,
sealants, paint, and other products may contain strong
solvents, such as acetone, which attack many
plastics, greatly reducing their strength.
IMPORTANT: The sensor must be in good contact
with the water at all times.
IMPORTANT: Read the instructions completely
before proceeding with the installation. These
instructions supersede any other instructions in your
instrument manual if they differ.
Mild household detergent or weak solvent (such as alcohol)
File (installation in a metal hull)
Marine sealant (suitable for below waterline)
Additional washer [for aluminum hull less than 6mm (1/4") thick]
Slip-joint pliers (installing a metal housing)
Grommets (some installations)
Installation in a cored fiberglass hull (see page 3)
Hole saw for hull interior60mm or 2-3/8"
Fiberglass cloth and resin
or Cylinder, wax, tape, and casting epoxy
ultrasonic
insert
outside wall below
lower o-ring
Anti-fouling Paint
Aquatic growth can accumulate rapidly on the ultrasonic sensor’s
surface reducing performance within weeks. Surfaces exposed to
salt water must be coated with anti-fouling paint. Use water-based anti-fouling paint only. Never use ketone-based paint, since
ketones can attack many plastics possibly damaging the sensor.
It is easier to apply anti-fouling paint before installing the sensor,
but allow sufficient drying time. Reapply paint every 6 months or
at the beginning of each boating season. Paint the following
surfaces (see Figure 2):
• Outside wall of the ultrasonic insert below the lower o-ring
• Active face of the ultrasonic insert
• Exterior flange of the housing and valve assembly
• Bore of the valve assembly up 30 mm (1-1/4")
• Blanking plug below lowest o-ring including exposed end
Mounting Location
CAUTION: Do not mount near water intake or discharge openings
or behind strakes, fittings, or hull irregularities that will disturb the
water flow.
CAUTION: Never mount the sensor directly ahead of a depth
transducer, since turbulence generated by the housing will
adversely affect the depth transducer’s performance, especially
at high speeds. Mount side-by-side.
CAUTION: Do not mount in line with trailer rollers or bunks that
may damage the sensor.
Turbulence-free water must flow under the ultrasonic sensor at all
speeds. Choose an accessible spot with a minimum of 280mm
(11") of headroom inside the vessel to allow for the height of the
housing, tightening the nuts, and removing the insert.
• Fin keel sailboats—Mount on or near the centerline and
forward of the fin keel 150–300mm (1/2 – 1').
• Full keel sailboats—Locate amidships and away from the keel
at the point of minimum deadrise.
• Displacement hull powerboats —Locate amidships near the
centerline.
• Planing hull powerboat — Mount well aft to ensure the sensor
is in contact with the water at high speeds.
Installation
Hole Drilling
Cored fiberglass hull—Follow separate instructions on page 3.
1. Drill a 3mm or 1/8" pilot hole from inside the hull. If there is a rib,
strut, or other hull irregularity near the selected mounting
location, drill from the outside.
2. Using the 51mm or 2" hole saw, cut the hole perpendicular to
the hull from outside the hull.
3. Sand and clean the area around the hole, inside and outside, to
ensure that the sealant will adhere properly to the hull. If there is
any petroleum residue inside the hull, remove it with either mild
household detergent or a weak solvent (alcohol) before sanding.
Metal hull—Remove all burrs with a file and sandpaper.
CAUTION: Be sure the surfaces to be bedded are clean and dry.
Apply a 2mm (1/16") thick layer of sealant around the flange of
the housing that contacts the hull and up the sidewall of the
housing. The sealant must extend 6 mm (1/4") higher than the
combined thickness of the hull, washer(s), and hull nut (see
Figure 3). This will ensure there is sealant in the threads to seal
the hull and to hold the hull nut securely in place.
Installing
CAUTION: The arrow on the flange of the housing must point
forward toward the bow for the insert to be aligned properly.
CAUTION: The bottom of the insert must be flush with the bottom
of the housing for the sensor to work properly.
1. From outside the hull, push the housing into the mounting hole
using a twisting motion to squeeze out excess sealant (see
Figure 3). Align the arrow on the flange of the housing pointing forward toward the bow. If the sensor is not installed on the
centerline, angle the housing slightly toward the centerline to
align it with the water flow.
2. From inside the hull, slide the washer onto the housing.
Aluminum hull less than 6mm (1/4") thick —Use an
additional rubbery, fiberglass, or plastic washer. Never use
bronze since electrolytic corrosion will occur. Never use wood,
since it will swell possibly fracturing the plastic housing.
3. Screw the hull nut in place being sure the notch on the upper
rim of the housing and the corresponding arrow on the flange
are still positioned forward toward the bow.
Plastic housing—Do not clamp tightly on the wrenching flats,
causing the housing to fracture.
Plastic hull nut—Hand-tighten only. Do not over-tighten.
Metal hull nut—Tighten with slip-joint pliers.
Cored fiberglass hull—Do not over tighten, crushing the hull.
Wood hull—Allow the wood to swell before tightening the hull nut.
4. Remove any excess sealant on the outside of the hull to ensure
smooth water flow under the ultrasonic insert.
5. After the sealant cures, inspect the o-rings on the valve
assembly (replace if necessary) and lubricate them with the
silicone lubricant supplied. The o-rings must be intact and well
lubricated to make a watertight seal.
6. Slide the valve assembly into the housing being sure to engage the key in the notch.
7. Screw the cap nut in place. Hand-tighten only. Do not over tighten.
8. Inspect the o-rings on the ultrasonic insert (replace if
necessary) and lubricate them with the silicone lubricant
supplied (see Figure 6). The o-rings must be intact and well
lubricated to make a watertight seal.
9. Slide the ultrasonic insert into the housing with the arrow on the
top pointing forward toward the bow. Seat it into place with a
pushing twisting motion until the key fits into the notch. The
arrow on the top of the insert, the notch in the housing, and the
arrow on the flange will be aligned. Be careful not to rotate the housing and disturb the sealant. Be sure the bottom of the insert
is flush with the bottom of the housing.
10.Attach one safety ring to one end of the retaining pin. Slide the
retaining pin through the valve assembly and the ultrasonic
insert. Attach the second safety ring to the retaining pin (see
Figure 3).
11.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.
Plastic housing—Attach the safety wire to one eye in the hull
9-12 mm
pour in
casting
epoxy
hull thickness
(3/8- 1/2")
larger than the
hole through the
hull’s outer skin
nut. Thread the short emergency plug onto the wire. Keeping
the wire taut throughout, lead the wire in a counterclockwise
direction and thread it through one eye in the cap nut. Lead the
wire through the eye a second time. Then lead the wire through
the safety ring and the second eye in the cap nut. Twist the wire
end securely to itself.
Metal housing—Wrap one end of the safety wire tightly around
the housing and twist it together with the long end. Thread the
short emergency plug onto the wire. Keeping the wire taut
throughout, lead the wire straight up and through one eye in the
cap nut. Loop the wire through one safety ring. Twist the it
securely to itself.
12.To wire the ultrasonic speed sensor, follow the instructions
“Wiring” on page 5.
Checking for Leaks
When the boat is placed in the water, immediately check around
the sensor for leaks. Note that very small leaks may not be readily
observed. Do not to leave the boat in the water unchecked for more
than 3 hours. If there is a small leak, there may be considerable
bilge water accumulation after 24 hours. If a leak is observed,
repeat “Bedding” and “Installing” immediately (see page 3).
Installation in a Cored Fiberglass Hull
The core (wood or foam) must be cut and sealed carefully. The core must
be protected from water seepage and the hull must be reinforced to prevent
it from crushing under the hull nut allowing the housing to become loose.
CAUTION: Completely seal the hull to prevent water seepage into
the core.
1. Drill a 3mm or 1/8" pilot hole from inside the hull. If there is a rib, strut,
or other hull irregularity near the selected mounting location, drill from
the outside. (If the hole is drilled in the wrong location, drill a second hole
in a better location. Apply masking tape to the outside of the hull over the
incorrect hole and fill it with epoxy.)
2. Using a 51 mm or 2" hole saw, cut the hole from outside the hull through
the outer skin only (see Figure 5).
3. From inside the hull, use a 60mm or 2-3/8" hole saw to cut through the
inner skin and most of the core. The core material can be very soft.
Apply only light pressure to the hole saw after cutting through the inner
skin to avoid accidentally cutting the outer skin.
4. Remove the plug of core material so the inside of the outer skin and the
inner core of the hull are fully exposed. Sand and clean the inner skin,
core, and the outer skin around the hole.
5. If you are skilled with fiberglass, saturate a layer of fiberglass cloth with
a suitable resin and lay it inside the hole to seal and strengthen the
core. Add layers until the hole is the correct diameter.
Alternatively, a hollow or solid cylinder of the correct diameter can be
coated with wax and taped in place. Fill the gap between the cylinder and
hull with casting epoxy. After the epoxy has set, remove the cylinder.
3
6. Sand and clean the area around the hole, inside and outside, to ensure
that the sealant will adhere properly to the hull. If there is any petroleum
residue inside the hull, remove it with either mild household detergent
or a weak solvent (alcohol) before sanding.
7. Proceed with “Bedding” and “Installing” on page 3.
Operation, Maintenance & Repair
How the Valve Works
The valve is not a watertight seal! The sensor incorporates a
self-closing valve which minimizes the flow of water into the
vessel when the ultrasonic 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. Always use the ultrasonic insert or the
long blanking plug secured with the retaining pin, safety rings, and
safety wire for a watertight seal.
Using the Long Blanking Plug
To protect the ultrasonic insert, 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.
• Aquatic growth build-up is suspected due to inaccurate
readings from the instrument.
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 6). The o-rings must be
intact and well lubricated to make a watertight seal.
2. Remove the ultrasonic insert from the housing by removing the
safety wire, one safety ring, and the retaining pin.
Do not remove the cap nut (see Figure 3).
3. Grasp the ultrasonic insert and pull upward slowly.
NOTE: In the unlikely event that the ultrasonic insert cannot be
removed, see “Servicing the Valve Assembly” below.
4. Slide the long blanking plug into the housing with the arrow on
the top pointing forward toward the bow. Seat it into place with a
pushing twisting motion until the key fits into the notch (see
Figure 6). Secure it with the retaining pin and safety rings.
5. Reattach the safety wire to prevent the insert from backing out
in the unlikely event that the cap nut fails or is screwed on
incorrectly (see Figure 3).
Servicing the Ultrasonic Insert
CAUTION: The active face of the ultrasonic insert is fragile thus
easily damaged. Do not scratch, gouge, or sand it with coarse
sandpaper.
Aquatic growth will seriously affect the ultrasonic insert’s performance.
Clean the active face with a dull putty knife being careful to avoid
scratching the surface (see Figure 6). If fouling is severe, lightly wet
sand the surface with fine grade (#320) wet/dry paper.
O-rings must be free of abrasions and cuts to ensure a watertight
seal. Install three small o-rings on the ultrasonic insert (see Figure 6).
Place the remaining three small o-rings on the long blanking plug.
Servicing the Valve Assembly
Should the valve fail, remove it for servicing. A replacement
o-ring and Valve Kit 33-415 is available.
WARNING: If the insert is caught in the valve assembly trapping
the cap nut, TEMPORARILY hold the SHORT emergency plug in
place with the safety wire. Immediately, separate the insert from
the valve assembly. If they cannot be separated and the sensor
must be left unattended, cut the cable [a minimum of 1m (3') from
the insert] to free the cap nut. Later, splice the cable using
Airmar’s Junction Box 33-035.
1. Remove the short emergency plug from the safety wire (see
Figure 3).
2. Inspect (replace if necessary) and lubricate the o-rings with
silicone lubricant or petroleum jelly (Vaseline
must be intact and well lubricated to make a watertight seal.
3. Unscrew the cap nut. With the short emergency plug ready in
one hand, remove the ultrasonic insert and valve assembly as
one unit. Rapidly insert the short emergency plug to minimize
the flow of water into the boat.
NOTE: The short plug is not secure until the cap nut is in place
4. To free the cap nut, remove the ultrasonic insert from the valve
assembly by removing one safety ring and the retaining pin.
Grasp the ultrasonic insert and pull upward slowly.
5. Secure the short emergency plug with the cap nut. Hand-tighten only. Do not over tighten. Reattach the safety wire.
6. Clean, repair, or replace the valve assembly, so the flap valve
moves freely and seats against the valve housing (see Figure 6).
7. To reinstall the valve assembly and ultrasonic insert, inspect
(replace if necessary) and lubricate the o-rings with silicone
lubricant or petroleum jelly (Vaseline
®
intact and well lubricated to make a watertight seal.
8. Remove the safety wire and cap nut from the short emergency
plug. With the valve assembly ready in one hand, remove the
emergency plug. Rapidly slide the valve assembly into the
housing being sure to engage the key in the notch. Screw the
cap nut in place and hand-tighten only. Do not over tighten.
9. Reinstall the ultrasonic insert and secure it with the retaining pin
and safety rings. Attach the safety wire to the short emergency
plug, the cap nut, and the safety ring (see Figure 3).
®
). The o-rings
). The o-rings must be
Winterizing
After the boat has been hauled for winter storage, remove the
long blanking plug to let the water drain away before reinserting it.
This will prevent any water from freezing around the blanking plug
and possibly cracking it.
CAUTION: Minimize electrical interference by separating the
sensor cables from other electrical wiring and the engine.
CAUTION: Be careful not to tear the cable jackets when passing
them through the bulkhead(s) and other parts of the boat. Use
grommets to prevent chafing.
1. Select a convenient, dry, mounting location for the water-
resistant junction box, about 1–2m ( 3' – 5') from the instrument
(see Figure 7).
2. Route the sensor cable to the proposed location of the junction
box. Do not fasten the cable in place at this time.
3. Hold the junction box at the selected location and mark the
position of the four screw holes with a pencil.
NOTE: If the junction box will be mounted on a vertical surface,
face the compression bushings downward to avoid water
seeping into the box.
4. At the marked locations, drill a 3mm or 1/8" hole to a depth of
10mm (3/8"). Do not screw the junction box in place at this time.
screw hole (4)
RED
BLK
BATTERY
BRN
BARE
WHT
INSTRUMENT
RED
GRN
WHT
BLK
RED
GRN
SENSOR
BRN
grey
wire with
protective
sleeving
5. Route the instrument cable to the junction box. Cut the cable
50cm (2') beyond the junction box to allow for wiring ease.
Do not fasten the cable in place at this time.
6. Route the power cable from the battery to the junction box.
Allowing 25cm (10") at each end for wiring ease, cut the cable
to length. Do not fasten the cable in place at this time.
Preparing the Cables
CAUTION: Be careful not to damage the printed circuit board.
Be sure the power is ‘OFF’. Remove the junction box cover
1.
and set it aside along with the screws (see Figure 8).
2. Carefully push approximately 200mm (8") of the power cable
through the left compression bushing.
3. Carefully push approximately 200mm (8") of the instrument
cable through the center compression bushing,.
4. Carefully push approximately 200mm (8") of the sensor cable
through the right compression bushing.
5. Strip 60mm (2-1/2") of the outer jacket and foil shielding from
the cut ends of the power and instrument cables (see Figure 9).
NOTE: The grey wire is covered with protective sleeving and
this must remain in place.
6. Strip 11mm (3/8") of conductor insulation from the end of each
insulated wire in the power and instrument cables.
7. Protect the cable’s foil shielding from causing a short inside the
junction box. Place heat-shrink tubing around the jacket where
the wires emerge from the cable. It must overlap the wires a
minimum of 6mm (1/4"). Use a heat gun to shrink the tubing.
CAUTION: Sensor cable—Do not attempt to connect the bare
wire and grey wire. The bare wire has been cut off flush with the
cable jacket, and the grey wire has been covered with protective
sleeving. Do not allow these wires to cause a short circuit within
the junction box.
1. From outside the junction box, carefully pull each of the cables
in turn until only 13mm (1/2") of the cable jacket remains inside
the box (see Figure 10).
2. Starting with the battery cable, wire each cable in turn to the
corresponding terminal block. Follow the color code on the PC
board. Insert the stripped end of a wire in the hole in the
corresponding terminal. Simultaneously depress the adjacent
button using a small blade screwdriver. Release the button to
lock the wire in place. Be sure the stripped end of the wire is inserted up to the insulation only. Do not include any insulation
inside the terminal. Gently tug on the wire to ensure it is locked
in place. Repeat this process until all wires are connected.
3. Hand-tighten the nut on each compression connector to make
a water-resistant seal.
4. Arrange the wires neatly inside the junction box being sure that
no bare wires are touching.
5. Attach the junction box cover with the screws provided for a
water-resistant seal.
6. Using the screws provided, attach the junction box to the
selected mounting surface at the holes previously drilled.
Wiring the Instrument
To connect the instrument cable to the display, follow the
instructions in your instrument owner’s manual for connecting a
speed sensor. See the color code below.
RedB+ (5 to 15VDC)
Green (GRN)signal
Bareground
White (WHT)temperature
Brown (BRN)temperature
Wiring the Power Panel (Battery)
Be sure the power panel has a 0.5 amp fast blow fuse or circuit
breaker.
Cut off the bare wire flush with the cable jacket. To connect
the power cable to the power panel, see the color code below.
RedV+ (10 to 15 VDC)
BlackV–
Troubleshooting
No Speed Reading
• Is the ultrasonic insert installed in the housing and connected to
the junction box?
• Is the ultrasonic insert oriented with the arrow on the top pointing
forward toward the bow? If the insert cannot be seated in the
housing with the arrow pointing forward, check that the arrow on
the flange of the housing is pointing forward. If this is not the case,
the housing needs to be reinstalled with the proper orientation.
• Is power being supplied to the junction box? The power must be
10 to 15VDC. At lower voltages performance is degraded and
the unit will shut down. If there is no voltage, check the wiring.
• Are the wire connections at the terminals in the junction box
tight and properly stripped of insulation?
• Does the color of each wire match the color label on the PC board?
®
AIRMAR
TECHNOLOGY CORPORATION
6
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
• If the ultrasonic speed sensor is ‘ON’ when the boat is
stationary, you may see a speed readout of a fraction of a knot
because of water movement under the hull.
• If the speed reading is consistently the same percentage higher
or lower than the true speed, the speed function within the
instrument needs to be re-calibrated. Follow the directions in
your instrument owner’s manual.
• If speed readings are inaccurate above about 10 knots:
- The sensor is installed in turbulent water. The cause may be
water intake or discharge openings, strakes, fittings, hull
irregularities upstream of the sensor, or the shape of the hull in
that area. The sensor must be reinstalled in another location.
- The ultrasonic insert is covered with aquatic growth. See
“Servicing the Ultrasonic Insert” on page 4.
- Aerated water is flowing under the sensor because the boat
is designed to pull air under the hull. The sensor will not work
on this type of boat.
Sensor Replacement & Parts
The information needed to order a replacement Airmar sensor is
printed on the cable tag. Do not remove this tag. When ordering,
specify the part number and date. For convenient reference,
record this information on the top of page one.
If you have purchased a plastic housing and have a wood hull or
desire greater strength, purchase a bronze housing. Lost, broken,
or worn parts should be replaced immediately.
Blanking
Plug
33-482-01
Cap NutHull Nut
04-234-1 (plastic)
02-131-01 (bronze)
04-004 (plastic)
02-030 (bronze)
Obtain parts from your instrument manufacturer or marine dealer.