CITY WATER COOLED
On citywater cooled models (Figure7) the lockshield
valve is manually adjusted with a key forthe required
minimum rate of water flow for cooling. Wheneverthe
ignition is turned on, the solenoid valve opens the
pressurized water inlet line.
During operation, water from the pressurized source
flows through the lockshield valve and solenoid valve
and the inlet line and enters at the bottom of the
cylinderwater jacket at two places, one entry for each
pair of cylinders. The water circulates around
and
up
the cylinder jacket through the cylinder heads where
it
leaves the engine through a thermostat and cover at
each
of
the two cylinder heads. From the thermostat
covers, the water passes through the exhaust mani-
fold and is drained from the engine cooling system.
During engine warmup, when the thermostats are
closed, a water by-pass line controls the amount of
water through the cylinder water jacket until the
thermostats open. The by-pass line also continues to
function during operation because
it
contains the
high water temperature cut-off switch and the water
temperature sender unit.
Ventilation for these models is necessary for suffi-
cient fresh air movement
to
cool the generator and
support combustion for the engine.
HIGH
WATER
TEMPERATURE
Check the thermostat opening and closing with the
thermostat immersed in a water bath. The thermostat
should start to open when the water temperature
reaches
145°F
and should be fully open at 165°F.
Take the thermostat out of the water and
it
should
close in approximately 60 seconds. If
it
does not
operate properly, replace
it.
HEAT EXCHANGER COOLING
(Optional)
ONAN heat exchanger cooling is available eitherfac-
tory installed or as a kit for customer installation. A
complete heat exchanger installation (Figure 7a)
contains two independent water systems:
1.
A closed water system
2.
An open (raw) water system
In
the closed water system, a centrifugal pump draws
the water from an expansion tank and pumps it
through cooling tubes in a heat exchanger and into
the engine water jacket where
it
circulates out through
a thermostat back into the expansion tank for recircu-
lation. In the open water system, pressurized water is
forced around the cooling tubes through the heat
exchanger and through the exhaust manifold from
where it is discharged.
WATER TEMPERATURE
SENDERUNIT
CUT-OFF SWITCH WATER BY-PASS
AW WATER INLET LINE
LENOID VALVE
LEG END
+
-
WATER INLET
--*--*
CIRCULATION
\',
./\N-
WATER
OUTLET
FIGURE
7.
CITY
WATER COOLING SYSTEM
19
Redistribution or publication of this document,
by any means, is strictly prohibited.
To Next Page
Loading...
Need help?
General
