Onan UF Series Instruction Manual And Parts Catalog page 63

I N S T A L L A T I O N
3. Dusty or Damp Conditions. - Avoid excessive dusty or damp con-
ditions as much as possible. Rust and
dirt are enemies of any piece of machinery. The generator is drip
proof in design, but unnecessary exposure to moisture should be avoided.
The generator should be mounted under cover or inside a building to
protect it against the weather.
4. Servicing Convenience. - To permit easy access for servicing the
bearings and brushes, allow at least 24
inches of space around the generator.
5. Wiring Convenience. - Locate the generator as near as possible to
the electrical equipment it is to serve.
GENERATOR COOLING. - The generator blower system uses a revers-
ible scroll. When the blower scroll is in-
stalled properly, a strong flow of air comes out of the generator at the
generator drive shaft end. Lack of air flow indicates improper instal-
lation of the blower scroll. See paragraph on "REVERSING THE
SCROLL".
MOUNTING THE GENERATOR. - The mounting surface must be flat so
that the generator mounting base will
not be sprung, when tightened into place. It should be possible to turn
the generator shaft by hand after the generator is bolted down.
WIRING CONNECTIONS. - The generator external leads are not con-
nected, and their manner of connection will
depend upon whether a rheostat is to be used, and the DIRECTION OF
ROTATION. Refer to the wiring diagram. A rheostat of the proper
size should be installed if the speed variation will be too great, or if it
is necessary to reduce the voltage at light loads. The addition of a
rheostat will not raise the voltage above that which could be obtained
without the rheostat. A circuit breaker between generator and load is
recommended.
Follow specifications of local and national electrical codes for install-
ing wiring and grounding the generator. Be sure to use wire large
enough to avoid excessive drop in voltage between the generator and the
load, depending upon the distance and the amount of the load.
The proper size and type of driving unit for the generator is important
for satisfactory operation of the generator. When a gasoline or diesel
engine is used the following factors should be considered:
1. Engine Power. - The engine must have a minimum of 2 horsepower
for each 1000 watts of generator output. For ex-
ample, if a 5000 watt generator is to be operated, the engine must
deliver at least 10 horsepower at the drive shaft. If the engine has a
considerable reserve of power the speed regulation and voltage regula-
tion will be much better.