Nidec 22765-01, Руководство пользователя

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Page 27
Idling
Unless the voltage regulator has V/Hz protection built in, having the
generator set in operating mode while idling the engine can cause
permanent equipment damage. If engine adjustments require that
the engine be run at idle speed and the regulator does not have V/Hz
protection, make the generator regulating system inoperative during
idling by one of the following methods:
When the generator is provided with a voltage shutdown switch, be
sure the switch is set to the idle position while the engine is running at
idle speed.
Where the generator set is provided with field circuit breakers, set the
circuit breaker to the off position while the generator is running at idle
speed.
Where the generator set is provided with an automatic/manual control
switch that has an off position, switch it to off while the engine is
running at idle speed.
Where the generator set does not have any of the above options,
remove the wires from the voltage regulator input power terminals
when the engine is running at less than rated speed.
Parallel Operation
For the generator to operate in parallel with a system in operation, the
phase sequence of the generator must be the same as that of the system.
Use transformers to reduce the voltage to an acceptable level.
The output voltage at the paralleling point must be the same as each
instant, which requires that the two voltages be of the same frequency,
same magnitude, same rotation, and in coincidence with each other.
Voltmeters indicate whether the voltage magnitude is the same, and
frequency meters indicate whether the frequencies are the same.
Whether the voltages are in phase and exactly at the same frequency is
indicated by a synchroscope or by synchronizing lamps.
A synchroscope can be used to indicate the difference in phase angle
between the incoming machine and the system. The generator can
be paralleled by using incandescent lamps connected as shown in
Figure 19. The voltage rating of the series lamps must equal the
voltage rating of the transformer-low voltage winding.
Each prime mover in the system must have the same speed regulating
characteristics, and the governors must be adjusted to give the same
speed regulation as determined by applying load that is proportional to
the full load rating of the generator.
The voltage regulator must include paralleling circuitry. In addition,
the voltage, droop settings and the V/Hz regulation characteristics
must be the same for all the voltage regulators. This will allow the
generators to properly share reactive loads.
WARNING: Shock hazard—Do not
make connections or otherwise make
contact with the generator leads or other
devices connected to them unless the
genset is stopped and the phase leads are
grounded. A rotating generator is always
producing some voltage and contact with
the leads or other devices connected may
result in serious injury or death.
CAUTION: Refer to the voltage
regulator manual for complete details
and possible additional instructions.
Damage to the rotating diodes, generator,
and voltage regulator can be caused if
the regulator is operated improperly.
IMPORTANT: If the polarity of the exciter
is reversed by flashing the field, it may be
corrected by interchanging the battery
leads.