Airmar D800 - Page 3

3. Screw the hull nut in place being sure the notch on the upper
rim of the housing and the corresponding arrow on the lip are
still positioned forward toward the bow.
Wood hull —Allow for the wood to swell before tightening the
hull nut securely.
Plastic housing — Do not clamp tightly on the wrenching flats,
possibly causing the housing to fracture.
Plastic hull nut — Hand - tighten only. Do not over tighten.
Metal hull nut —Tighten with slip-joint pliers.
4. Remove any excess sealant on the outside of the hull to ensure
smooth water flow over the depth transducer.
Warning : The O-rings must be intact and well lubricated to
make a watertight seal.
5. After the sealant cures, inspect the O-rings on the insert
(replace if necessary) and lubricate them with the silicone
lubricant supplied.
6. Slide the insert into the housing with the arrow on the top
pointing forward toward the bow. Screw the cap nut several
turns until there is resistance.
Rotate the insert until the key
engages the notch in the housing. The arrow on the top of the
insert, the cable exit, the notch in the housing, and the arrow on
the lip will all be aligned. Continue to tighten the cap nut. Be
careful not to rotate the housing and disturb the sealant. Hand -
tighten only. Do not over tighten.
Warning : 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.
7. Attach the safety wire.
Plastic housing —Attach the safety wire to one eye in the hull
nut. Lead the wire in a counterclockwise direction and thread it
through one eye in the cap nut, the eye in the insert, the second
eye in the cap nut, and the second eye in the hull nut. Twist the
wire securely to itself.
Metal housing —Wrap one end of the safety wire tightly around
the housing and twist it together with the long end. Lead the
wire straight up and through one eye in the cap nut. Thread the
wire through the eye a second time. Then lead the wire
counterclockwise and through the eye in the insert. Twist the
wire securely to itself.
Cable Routing and Connecting
Caution : If your sensor came with a connector, do not remove it
to ease cable routing. If the cable must be cut and spliced, use
Airmar’s splash-proof Junction Box 33-035 and follow the
instructions provided. Cutting the cable or removing the
connector, except when using Airmar’s junction box, will void the
warranty.
1. Route the cable to the instrument being careful not to tear the
cable jacket when passing it through the bulkhead(s) and other
parts of the boat. To reduce electrical interference, separate the
sensor cable from other electrical wiring and the engine. Coil any
excess cable and secure it in place with zip-ties to prevent
damage.
2. Refer to the instrument owner’s manual to connect the sensor
to the instrument.
Checking for Leaks
Warning : Never install a thru-hull sensor and leave the boat in the
water unchecked for several days.
When the boat is placed in the water, immediately check around
the thru-hull sensor for leaks. Note that very small leaks may not
be readily observed. It is best not to leave the boat in the water for
more than 3 hours before checking it again. 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 2).
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.
Warning : Always wear safety goggles and a dust mask.
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.)
3
marine sealant
Figure 3. Bedding and installing
(low profile housings shown)
cap nut
washer
hull
plastic housing
safety wire
housing
hull nut
insert
marine sealant
stainless steel housingbronze housing
isolation
bushing
washer
in metal hull
(housing and isolation bushing)
(plastic)
marine sealant
cap nut
hull
safety
housing
insert
(plastic)
(metal)
hull nut
wire
(enlarged to show detail)