Westerbeke BTDA 15.0 Operator's Manual & Installation Manual page 55

Fresh Water Circuit
Fresh water is pumped through the engine by a
be~-driven
circulating pump, absorbing heat
from the engine. The fresh water coolant circulates through the engine's block absorbing heat,
then passes through the thermostat into the exhaust manifold, to the heat exchanger where it
is cooled, and then is returned to the engine block through the suction side of the fresh water
circulating pump. When the engine is started cold, external fresh water flow is prevented by
the closed thermostat (although some fresh water flow is bypassed around the thermostat to
prevent the exhaust manifold from overheating). As the engine warms up, the thermostat
gradually opens, allowing the engine's fresh water coolant to flow unrestricted to the external
portion of the cooling system.
Fresh Water Pump Drive Belt Tension
Generator models come equipped with be~ guards that cover over the beit(s) on the front of
the engine. ('Out of sight out of mind.' The bett guard is not installed for that purpose.)
Operators are advised that the inspection, service, and maintenance spoken of below should
be followed.
M'ARNiNGI
Never attempt to adjust the drive beWs tension while the engine is in
operation.
PAOTIONI
Check Water Pump Belt Drive Tensionl
Excessive water pump drive be~ tension can cause rapid wear of the
beit and reduce the service life of the fresh water pump's bearings.
Excessive slack or the presence of oil on the beit can cause beit
slipping resulting in high operating temperatures.
The water pump drive bett is properly adjusted if the beit can be deflected no less than
3/8 inch and no more than 1/2 inch (10 mm, 12 mm) as the beit is depressed with the
thumb at the midpoint between the two pulleys on the longest span of the beit. A spare
drive beit should be carried on board ..
Fresh Water Coolant (Antifreeze) Mixture.
A freshwater and antifreeze mixture should be used year-round in the cooling system. Water,
when it freezes, expands sufficiently to split the heat exchanger and crack the engine block.
A water/antifreeze mixture of proper concentration will prevent freezing.
Use soft water with few impurities, such as tap water (potable water) or rainwater. Never use
hard or foul water. Use of hard water or water containing impurities will lead to the collection
of scale in the engine and heat exchanger which will reduce the cooling system's efficiency.
15.0KWBTDA
53
Westerbeke Generators