Voltage Adjustment
The voltage level and voltage droop adjustments
determine the amount of circulating currents between
generators.
Carefully
matched
voltage
regulator
adjustments will reduce the circulating currents. Loads
of .8 power factor (primarily motors) require a generator
voltage droop of about 5%. Voltage droop is expressed
as the percentage of voltage change from no load to full
load. Use the same voltmeter to make adjustments on
each unit to be paralleled.
1. Adjust voltage as described for Single Unit Operation,
Initial Start-Up.
2. With the engine running at high idle, turn the voltage
droop clockwise about 1/2 of full range. If driven load is
to be unity power factor, set the voltage droop control on
all generators at 1/2 of full range and proceed to Step 7.
If driven load is to be normal (0.8 power factor) proceed
to Step 3.
3. Readjust the voltage level control until the voltage is
about 5% above desired voltage.
4. Apply full load at .8 power factor.
NOTE: If a generator is to be paralleled with other
generators, the voltage droop of each generator
must be the same to satisfactorily divide reactive
load.
5. Readjust the voltage droop control to obtain desired
voltage with full load at .8 power factor.
6. Repeat Steps 3, 4 and 5 for each generator to be
paralleled until line voltage is equal to desired level at .8
power factor and no load voltage is approximately 5%
above rated voltage.
7. Parallel generators and apply the driven load (see the
topic Operation/Paralleling). If the sum of the amps of
the individual generator amperes exceeds the total amps
going to the load by 10% at full load, adjust voltage
droop controls to share current proportionally between
generators.
CAUTION
Do NOT exceed rated ampere load on
any single generator.
8. Tighten the locknuts on all controls and install the
access cover. Condition 3 has been met.
Starting Multiple Units
Starting-Units are started the same as single units.
Paralleling
Units may be paralleled at no load or paralleled with
units under load. To parallel two or more units the
following conditions must be met:
1. Same phase rotation.
2. Same voltage level.
3. Same voltage droop.
4. Same frequency.
5. Voltages must be in phase.
The first three conditions have been met in the initial
start-up for parallel operation.
1. Start the unit to be paralleled according to the
procedure in the engine operation section.
2. Turn the synchronizer lights on.
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