Raw Water Discharge; Raw Water Supply Hose; Measuring Back Pressure; Changing Catalyst - Westerbeke 3.5 SBCG Operator's Manual

INSTALLATION/EXHAUST SYSTEM
RAW WATER DISCHARGE
The fresh water that flows thru the engine is cooled by a
continuous flow of raw water (via the heat exchanger). As
the raw water is discharged overboard, it is used to cool
the exhaust system.
RAW WATER SUPPLY HOSE (INSTALLING)
The raw water supply hose from the discharge conne-::tion on
the engines cooling system to the inlet connection of the
water injected exhaust elbow must be looped a minimum of
12 inches (30cm) above the vessels loaded water line ..
On installations where the water injected exhaust is close to
or below the vessels loaded water line, provisions must be
made to install a syphon break in the raw water supply hose.
The function of the syphon break is to stop the raw water
flow after the engine is shutdown. This flow, if not stopped,
will fill the exhaust system and possibly the engine as well.
The raw water supply hose must be looped well above the
loaded water line to allow the syphon break to function
during all attitudes of vessel operation to prevent syphoning
when the generator is not operating.
When the generators location is above the loaded water line
of the vessel during all attitudes of vessel operation, it is still
advisable to loop theraw water discharge hose at least 6 •
inches or more above the generator and then down to the
inlet connection on the water injected exhaust elbow.
NOTE:
Always use a quality hose with good wall integrity or
wire reinforced hose so it will maintain its shape when
looped and also provide proper mechanical support for the
hose.
CO TEST PORT
SIPHON BREAK
WHEN A SIPHON BREAK AVAILABLE FROM
IS NOT REQUIRED
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YOUR WESTERBEKE
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HEAT EXCHANGER
EXHAUST BACK PRESSURE
Measure back pressure after the engine has
reached its normal operating temperature and
with rated an1perage output applied to the
generator (30 amps @60Hz and 15 amps @ 50Hz).
Westerbekes Installation Manual Pub. #43400
has detailed information on back pressure.
BACK PRESSURE SHOULD
NOT EXCEED 41" (102.5cm)
IN THE WATER COLUMN OR
EXCEED 1.5 PSI WHEN USING
A PSI GAUGE.
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WATER
COLUMN
MEASURING
EXHAUST BACK
PRESSURE
Engine$ & Generators
6
'
\
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POSITION THE CLAMP OVER
"
"
THE TWO FLANGES (AND GASKET)
AND TIGHTEN SECURELY
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