Westerbeke 9.0 BCG Technical Manual page 28

The generator's engine is fresh water cooled by an engine-mounted heat exchanger. Sea water is used as
the heat exchanger's cooling medium. Sea water is pumped through the heat exchanger by a belt-ciriven,
positive displacement rubber impeller pump. After the sea water cools the fresh water that circulates through
the heat exchanger, the sea water is then injected into the exhaust discharge, carrying with it the heat removed
from the engine's fresh water system.
The engine's fresh water coolant is circulated by means of a belt-ciriven, centrifugal type metal impeller pump
mounted on the side of the engine. The fresh water coolant's temperature is thermostatically controlled. A
plastic fresh water system coolant recovery tank is supplied with each engine. It is mandatory that this
coolant recovery tank be installed and used.
DC Control Circuit
This circuit is designed and manufactured in compliance with United States Coast Guard Standards (33 CFR
PART 183). No modifications may be made to it by the installer or user. It is the installer's responsibility to
assure that the installation of the generator set and any remote start panels or remote instrument panels are
installed in compliance with the above Coast Guard Standards. Failure to observe these requirements could
be the cause of injury.
Electrical System Characteristics
The generator is started by a conventional, separate cranking motor which includes a self-contained, posi-
tive-engaging starter solenoid. The starter is internally-grounded to the engine block. The BTG 9.0KW gen-
erator has an externally mounted alternator. This alternator provides approximately 35 amps of battery
recharging capacity. The BTG 9.0's alternator is internally grounded to the engine block. The BCG 4.0 and
6.5KW generator sets have auxiliary windings built into the generator end which provide up to 10 amps for
battery recharging. A 20 amp DC circuit breaker, located within 7 inches of the battery connection to the
starter solenoid, protects all subsequent wiring. This circuit breaker is manually resettable. Three manual-
ly-operated momentary toggle switches are used to start and stop these model generator sets. To keep the
control circuit simple and reliable in a marine environment, no relays have been incorporated in this electri-
cal design.
On the BCG 4.0 and 6.5KW generator sets, three panel-mounted
fuses are installed to protect the starter circuit, the running B
+
cir-
cuit (which runs through the protective switches), and the remote
panel circuit. On the BTG 9.0KW generator set, only two protective
fuses are needed.
The choke is automatic and electrically operated. The ignition sys-
tem has conventional points and condenser. An overspeed shut-
down switch shuts off the generator set by grounding out the ignition
B ANP
ICNITION
FUSE
system should the engine's rpms reach approximately 2175. This overspeed switch consumes 25 milliamps
(.025 or 1/4th of an amp) at all times once the generator is connected to its battery. As this only amounts to
about 18 amp-hours in a month, it is unnecessary to be concerned with this slight discharge during normal
operation. If the generator set were to be unattended for many months, the two easiest ways to stop this
slight drain is to first turn off the main battery switch providing 12 volts to the generator set, and second to
remove the ignition fuse on the generator-mounted control panel.
Westerbeke Generators 22