Installation Instructions

ManualsBrandsFuruno ManualsTransducersFuruno 525T-BSD

17-008-05 rev. 04 12/01

Thru

hull Metal Stem Depth Transducer

Models: B39, B45, B46, B49, B240,

B250, B256, B260, SS505

Applications

•

Bronze housing

recommended for ﬁberglass or wood hulls only.

Caution

: Never mount a bronze housing in a metal hull, because

electrolytic corrosion will occur.

•

Stainless steel housing

is compatible with all hull materials.

•

Aluminum or steel hull

—Use a stainless steel housing to

prevent electrolytic corrosion.

Caution

: Installation requires using a fairing kit to isolate the

stainless steel sensor from a metal hull.

•

Caution

: Never install a metal housing on a vessel with a

positive ground system

Tools and Materials

Fairing (

mandatory for SS505

)

Digital level

bubble level & protractor (installation w/ fairing)

Safety goggles

Dust mask

Band saw

hand saw (installation with a fairing)

Rasp

power tool (installation with a fairing)

Electric drill

Drill bits:

Pilot hole 3mm

1/8"

B39, B49 26mm

B45, B46, SS505 22mm

7/8"

B240, B250, B260 33mm

1-5/16"

B256 30mm

1-3/16"

Sandpaper

Mild household detergent

weak solvent (alcohol)

Marine sealant

Slip-joint pliers

Zip-ties

Water-based antifouling paint (

mandatory in salt water

)

Installation in a cored ﬁberglass hull: (see page 3)

Drill bit for hull interior:

B39, B49 37mm, 38mm,

1-1/2"

B45, B46, SS505 35mm

1-3/8"

B240, B250, B260 42mm

1-5/8"

B256 40mm, 41mm,

1-5/8"

Cylinder, wax, tape, and casting epoxy

Identify Your Model

The model name is printed on the cable tag.

Mounting Location

Acoustic Noise

Acoustic noise is always present and these sound waves can

interfere with the operation of the transducer. Background noise

from sources such as: waves, ﬁsh, and other vessels cannot be

controlled. However, carefully selecting the transducer mounting

location can minimize the affect of vessel generated noise from

the propeller(s) and shaft(s), other machinery, and other echo-

sounders. The lower the noise level, the higher the echosounder

gain setting that can be used.

Placement

Choose a location where:

• The water ﬂowing across the hull is smoothest with a minimum

of bubbles and turbulence (especially at high speeds).

• The transducer will be continuously immersed in water.

• The transducer beam is unobstructed by the keel or propeller

shaft(s).

• There is a minimum deadrise angle.

• There is adequate headroom inside the vessel for the height of

the housing and tightening the nut.

Caution

: Do not mount the sensor:

Near water intake or discharge openings

Behind strakes, ﬁttings, or hull irregularities

Behind eroding paint (an indication of turbulence)

Boat Types

(see Figure 1)

•

Displacement hull powerboat

—Locate 1/3 aft LWL and

150–300mm (6–12") off the centerline on the side of the hull

where the propeller is moving downward.

•

Planing hull powerboat

—Mount well aft, on or near the

centerline, and

well inboard of the ﬁrst set of lifting strakes

insure that the transducer is in contact with the water at high

speeds. Mount on the side of the hull where the propeller is

moving downward.

Outboard and I/O

—Mount just forward of the engine(s).

Inboard

—Mount well ahead of the propeller(s) and shaft(s).

Step-hull

—Mount just ahead of the ﬁrst step.

Boat capable of speeds above 25kn

(29MPH)—Review

sensor location and operating results of similar boats before

proceeding.

•

Fin keel sailboat

—Mount to the side of the centerline and

forward of the ﬁn keel 300–600mm (1–2').

•

Full keel sailboat

—Locate amidships and away from the keel

at the point of minimum deadrise angle.

CAUTION

NEVER USE SOLVENTS

Cleaners, fuels, paint, sealants, and other products may

contain strong solvents, such as acetone, which can attack

many plastics greatly reducing their strength.

IMPORTANT

: Please read these instructions

completely before proceeding with the installation.

These instructions supersede any other instructions in

your instrument manual if they differ.

B45

standard fairing

OWNER’S GUIDE & INSTALLATION INSTRUCTIONS

Record the information found on the cable tag for future reverence.

Part No._________________Date___________Frequency________kHz

Summary of content (4 pages)

PAGE 1
OWNER’S GUIDE & INSTALLATION INSTRUCTIONS Thru-hull Metal Stem Depth Transducer Record the information found on the cable tag for future reverence. Part No._________________Date___________Frequency________kHz Models: B39, B45, B46, B49, B240, B250, B256, B260, SS505 17-008-05 rev. 04 12/01 B45 IMPORTANT: Please read these instructions completely before proceeding with the installation. These instructions supersede any other instructions in your instrument manual if they differ.
PAGE 2
Hull Thickness (measured perpendicular to the waterline) pressure waves 1/3 aft LWL (Load Waterline Length) 150-300mm (6-12") displacement hull Minimum Model no fairing B39, B49 19mm (3⁄4") B45 6mm (1⁄4") B46 19mm (3⁄4") B240 32 mm (11⁄4") B250, B256, B26019mm (3⁄4") SS505 6mm (1⁄4") Maximum no fairing 98mm (37⁄8") 92mm (25⁄8") 88mm (31⁄2") 152mm (6") 114mm (41⁄2") 104mm (41⁄8") Maximum with fairing 50mm (2") 50mm (2") 40mm (15⁄8") 83mm (31⁄4") 45mm (13⁄4") 56mm (21⁄4") Installation (no fairing or st
PAGE 3
band saw table 4. Apply a 2mm (1/16") thick layer of marine sealant to the surface of the fairing that will contact the hull. cutting guide 5. Apply a 2mm (1/16") thick layer of marine sealant to the surface of the backing block that will contact the hull Installing 1. From outside the boat, thread the cable through the mounting hole. deadrise angle 2. With the fairing in place and arrow facing forward toward the bow (if used), push the stem of the transducer into the mounting hole.
PAGE 4
Checking for Leaks Warning: Never install a thru-hull transducer 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 transducer 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.