Airmar HT200 Owner's Manual & Installation Instructions - page 3
Figure 3. Servicing
paddlewheel
flat side of
shaft
blade faces
small
valve
housing
valve housing
flap valve
insert
pull ring
cap nut
key
O-rings
assembly
direction of arrow on top
temperature insert
or blanking plug
insert nut
medium O-ring
Copyright © 2005 - 2016 Airmar Technology Corp.
BOW ►
of insert (toward bow)
paddlewheel
large o-ring
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.
Bronze 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 marine sealant on the outside of the hull to
ensure smooth water flow under the sensor.
5. The O-rings must be intact and well lubricated to make a
watertight seal. After the marine sealant cures, inspect the O-
rings on the valve assembly (replace if necessary) and lubricate
them with the silicone lubricant supplied (see Figure 3).
6. Slide the valve assembly into the housing. Seat it into place
with a pushing twisting motion until the key fits into the notch.
Screw the CAP nut in place and hand tighten only. Do not over
tighten.
7. Slide the insert nut along the cable until it rests on the top of the
insert. Attach the pull ring to the insert, capturing the insert nut.
8. The O-rings on the insert must be intact and well lubricated to
make a watertight seal. Inspect the O-rings on the insert
(replace if necessary) and lubricate them with the silicone
lubricant supplied.
9. Slide the insert into the housing. Seat it into place with a
pushing twisting motion until the key fits into the notch. Be
careful not to rotate the housing and disturb the sealant. Screw
the INSERT nut in place and hand tighten only. Do not over
tighten.
ST850—The paddlewheel insert must have the arrow on the top
pointing forward toward the bow. (The cable exit points away from
the bow.)
10.Always attach the safety wire to prevent the insert from
backing out in the unlikely event that the insert nut and/or cap
nut fails or is screwed on incorrectly (see Figure 2).
Plastic housing—Attach the safety wire securely to one eye in
the hull 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. Thread the wire through the eye a second time. Thread
it through the eye in the INSERT nut. Thread the wire through
the eye a second time. Loop the wire through the pull ring and
twist the wire securely to itself.
Bronze 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. Thread the wire through the eye a second
time. Lead the wire in a counterclockwise direction and thread it
through the eye in the INSERT nut. Thread the wire through the
eye a second time. Loop the wire through the pull ring and twist
the wire securely to itself.
Cable Routing & 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 No. 33-035 and follow the
instructions provided. Removing the waterproof connector or
cutting the cable, except when using a watertight junction box, will
void the sensor’s 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. Use grommet(s) to prevent chafing. 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 cable ties to prevent damage.
2. Refer to the instrument owner’s manual to connect the sensor
to the instrument.
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 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).
Retrofit Into ST650 Housing
The HT200 and ST850 insert can be installed in a new or existing
ST650 housing. However, the ST650 valve assembly inside
the housing must be replaced with the HT200/ST850 valve
assembly, so the new insert will fit. To replace the valve
assembly, follow the instructions “Servicing the Valve Assembly”
on page 4.
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