Thermostat; Zinc Anode; Heat Exchanger - Westerbeke SBEG Series Operator's Manual

COOLING SYSTEM
THERMOSTAT
A thennostat controls the coolant temperature as the coolant
continuously flows through the closed cooling circuit. When
the engine is first started the closed thennostat prevents coolant
from flowing (some coolant is by-passed through the thennostat
to prevent the exhaust manifold from overheating). As the
engine wanns up, the thennostat gradually opens. The
thennostat is accessible and can be checked, cleaned, or
replaced easily. Carry a spare thennostat and gasket.
GASKET
(APPLY SEALANT
TO BOTH SlOES)
THERMOSTAT TEST
If you suspect a faulty thennostat, place it in a pan of water and
bring to a boil. A working thennostat should open about
112"
ZINC ANODE
A zinc anode (or pencil) is located in the raw water cooling
circuit within the heat exchanger. The purpose of the zinc
anode is to sacrifice itself to electrolysis action taking place
in the raw water cooling circuit, thereby reducing the effects of
electrolysis on other components of the system. The condition
of the zinc anode should be checked monthly and the anode
cleaned or replaced as required. Spare anodes should be carried
on board.
NEW
REPLACE
CLEAN
&
REUSE
NOTE:
ElectlVlysis is the result of each particular installation
and vessel location, not that of the generator.
If the zinc anode needs replacement, hold the hex boss into
which the zinc anode is threaded with a wrench while
loosening the anode with another wrench. This prevents the
hex boss from possibly tearing off the exchanger shell. After
removing the zinc, note the condition of it. If the zinc is in
poor condition, there are probably a lot of zinc flakes within
the exchanger. Remove the end of the heat exchanger and
clean the inside of all zinc debris. Always have a spare heat
exchanger end gasket in case the present one becomes
damaged when removing the end cover. Replace the sealing
gasket (refer to your engine model's heat exchanger end
gasket part number), O-ring, cover, and install a new zinc
anode.
NOTE:
The threads of the zinc anodes are pipe threads and do
not require sealant. sealant should not be used as
it
may
insulate the zinc from the metal of the heat exchanger
housing preventing electrolysis action on the zinc.
O·RING
ZINC ANODE
RAW WATER DRAIN
HEAT EXCHANGER
Cool raw water flows through the inner tubes of the heat
exchanger. As the engine coolant passes around these tubes,
the heat of the internal engine is conducted to the raw water
which is then pumped into the exhaust system and
discharged. The engine coolant (now cooled) flows back
thr()ugh the
en~n"-
and the circuitrel'eatsitself.
The engine coolant and raw water are independent of each
other; this keeps the engine's water passages clean from the
hannful deposits found in raw water.
Heat Exchanger Service
After approximately 1000 hours of operation, remove, clean
and pressure test the engine's heat exchanger. (A local
automotive radiator shop should be able to clean and test the
heat exchanger.)
NOTE:
Operating in silty and/or tropical waters may require
that a heat exchanger cleaning be peifortned more often than
every 1000 hours.
Engines & Generators
13