Operation; Starting; Operating - Onan UF Series Instruction Manual And Parts Catalog

10 O P E R A T I O N
STARTING. - Be sure that the generator is connected for the direction
of rotation being used. Start up the generator and check
the voltage while running at no load and rated speed (1, 500-rpm for 50-
cycle generators and 1, 800-rpm for 60-cycle generators). The genera-
tor voltage should be as follows:
Generator Nameplate Approximate Line to Line
Voltage Rating No Load Voltage at Rated Speed
120/240 252
120/208 220
If the generator voltage at no load is not as specified above, adjust the
generator speed until no-load voltage is reached before proceeding.
Check the generator cooling air circulation. When the blower scroll
is installed properly, a strong current of air comes out of the drive
shaft end of the generator. See paragraph on REVERSING THE SCROLL
for proper installation of the blower s c r o l l .
OPERATING. - Connect the various electrical loads after the generator
voltage is adjusted to the proper value at no load. It
may be necessary to advance or retard the engine throttle control for
engine drive units to control the output voltage. This may also be
necessary when large changes in the electrical load are made.
Keep the electrical load on the generator within its nameplate rating.
Overloading the generator w i l l cause the voltage to be low, w i l l shorten
the life and void warranty. .
Consider load and installation characteristics to determine the proper
starting procedure which w i l l assure voltage build-up each time. F a i l -
ure of generator to build up voltage may occur when the starting load
is too heavy. (This is not lost residual magnetism if the voltage builds
up (1) when only partial load is connected, or (2) when load is connected
after generator reaches speed.)
A . When electric motor loads are connected, connect one at a time,
begin with largest motor, allow each to reach running speed, then
connect the next motor. Electric motors require much more cur-
rent for starting than when running at normal speed.
B . When a rheostat (to l i m i t voltage at higher speed or at light load) is
used, disconnect the load (turn switch or circuit breaker OFF) or
turn rheostat to decrease resistance, until generator reaches speed
to assure build up.
C. Turn off the lights to attain partial load or no load until generator
reaches speed. Incandescent light bulbs (lamps) draw as much as
eight times their rating until filaments heat up.