Start and operate the generator set in droop mode and allow it to stabilize at rated load, rated
voltage, and rated frequency (speed). During this period, readings of all engine control panel
instruments and thermal instrumentation shall be recorded at minimum intervals of 10 minutes. If
necessary, adjustments to the load, voltage, and rated frequency may be made to maintain rated
load at rated voltage and rated frequency; but adjustments to the voltage and frequency shall be
limited to the operator voltage and frequency adjust devices. No other adjustments to the voltage
and frequency control systems should be made. Adjustments to the load, voltage, or frequency
control systems shall be recorded on the data sheet. Stabilization will be considered to have
occurred when three consecutive readings of the lubricating oil temperature have remained constant
at the rated load. Minor variations in temperature are permissible provided that a continued increase
or decrease does not take place.
Perform this test using a resistive load only. Remove the reactive portion of the load after
Load the set to the maximum attainable load, and adjust the frequency to the rated value. Maintain
the load for 5 minutes.
Record all instrument readings.
Allow the set to cool at rated load for 10 minutes.
Results. Compare the maximum power value obtained to the values and conditions listed in Table 12-3.
12-28. START AND STOP TEST.
General. The generator set must start and stop without erratic operation when following the operating
instructions on the set. The start and stop test may be run concurrently with any of the above tests that meet the
requirements of step c, below.
Apparatus. A stopwatch is required.
Procedure. The following steps shall be repeated three times:
Using the watch and the operating instructions on the set, record the time required to start the set
and bring it to rated speed.
With the circuit breaker closed, operate the set at rated voltage, rated frequency, and no load for 5
Using the stopwatch and the operating instructions on the set, record the time required to stop the
The set shall come up to rated speed in 5 minutes.
The set shall stop without prolonged run-on in a maximum of 30 start and seconds.