Kohler Generator Sets 20--2800 kW - Manual (Page 28)

TP-5700 7/93 16 Section 4 Air Requirements
4.6 Liquid-Cooled Models
The three most common liquid cooling systems used for
generator sets are unit-mounted radiator, city water, and
remote radiator cooling. Since each involves somewhat
different
installation considerations, they will be
discussed separately.
4.7 Unit-Mounted Radiator Cooling
This is the most common cooling system used for
engine-driven generator sets 20 kW and larger. The major
system components are an engine-driven fan and
circulating water pump, a radiator, and a thermostat. The
pump circulates water through the engine until it reaches
operating temperature. Then the engine thermostat opens
and allows circulation through the radiator. It can also close,
restricting the flow as necessary to prevent overcooling.
The fan blows air from the engine side of the radiator across
the cooling surface as shown in Figure 4-8.
Cooling air flow can be reversed by using a suction fan,
but this is generally not recommended because it may
interfere with generator cooling air flow, which moves in
the same direction as the engine’s standard pusher fan.
Also, a suction fan would result in higher temperature
combustion air being drawn into the air cleaner,
reducing the maximum engine power available.
Whenever a generator set is installed inside a building or
enclosure, the radiator air should be ducted outside the
room or enclosure. A typical arrangement is shown in
Figure 4-8. Ductwork should be as short, straight, and
unobstructed as possible. Static pressure restrictions of
more than 1/2 inch (1.3 cm) water column on the radiator
outlet or inlet air will reduce air flow to the point of limiting
maximum power and/or ambient temperature that causes
overheating.
7
8
9
10
11
12
7. Self-supporting duct work
8. Air out
9. Air inlet opening 10. Pusher fan
11. Flexible section
12. Support legs
Figure 4-8 Radiator-Cooled Generator Set Installation