TM 5-6115-465-34
T0 35C2-3-446-2
NAVFAC P-8-625-34
TM 06858B/06859D-34
it re-enters and remains within the prescribed volt-
operator, specifically adjustments to voltage and
age band for the next load condition.
frequency adjust devices. Adjustments to the load,
voltage or frequency shall be noted on the stabiliza-
tion data sheet. Stabilization will be considered to
(c) Divide this distance by the chart
have occurred when four consecutive voltage and
speed (in inches per second). This will give the volt-
current readings of the exciter field either remain
age recovery time, in seconds.
unchanged or have only minor variations about an
equilibrium condition with no evident continued in-
(6) Determine the voltage regulation for all
crease or decrease in value after the last load, volt-
load changes (e. g. rated load to no load, 1/2 rated
age or frequency adjustment has been made.
load to no had to 1/4 load, etc. ) as follows:
(b) No further adjustments shall be
(a) Using the indicating voltmeter readings
subtract the load value of voltage from the no load
made to any set control for the remainder of this
value for each load change (e. g. step (a) to step (b)).
test except for the control panel frequency adjust
(For voltage regulators utilizing single-phase voltage
device.
sensing, the value of voltage in the sensed phase only
shall be used in the above calculations. For voltage
(c) For each of the conditions in the
regulators utilizing multi-phase voltage sensing the
following steps allow approximately 2 minutes between
average value of the sensed voltage shall be used. )
each adjustment and the subsequent instrument read-
ings.
(b) Convert each of the values obtained
in (a) above to a percentage of rated voltage by divid-
(d) Adjust the generator set frequency
ing by the rated voltage and multiplying by 100. This
for the specified maximum frequency at rated load.
is the voltage regulation expressed in percent.
Read and record all instrument readings.
(c) Repeat paragraph 7-15d. (1) above
(e) Adjust the generator set frequency for
substituting frequency for voltage.
the specified minimum frequency at rated load. Read
and record all instrument readings.
(d) Compare the results tabulated in
(f) Reduce the load to zero.
quirements of Table 7-1.
(g) Adjust the generator set frequency
7-16.
for the maximum attainable frequency. Read and re-
FREQUENCY ADJUST RANGE TEST.
cord all instrument readings. If the over frequency or
overspeed protection device actuates, read and record
a. General. It is necessary that the frequency
all instrument readings just prior to the point of actu-
of a generator set be adjustable to provide rated fre-
quency at various load conditions as required in cer-
ation and note on the data sheet that the protection de-
vice actuated.
tain applications and to synchronize two or more gen-
erator sets for parallel operation.
NOTE
b. Apparatus. Instrumentation for measuring
had conditions, field voltage and current, and
This step is not applicable to generator
ambient temperature shall be as describd and illus-
sets having governors that utilize a
trated in MIL-HDBK-705.
threaded shaft and lock nut(s) or other
mechanical means as a method of opera-
c . Procedure.
tor speed adjustment.
(1) Preparation for Test. Connect the
(h) Adjust the generator set frequency
load and field instrumentation in accordance with
for the minimum attainable frequency. Read and
the applicable figure of MIL-HDBK-705, method
record all instrument readings.
205.1, paragraph 205.1.10.
NOTE
(2) Test.
This step is not applicable to generator
(a) Start and operate the generator set
sets having governors that utilize a
and allow it to stabilize at rated load, rated voltage
threaded shaft and lock (nuts) or other
and rated frequency .
operator speed alingment.
(i) Repeat 7-16c (1) and 7-16c. (2)(a)
During this period, readings of the load and field
instrumentation shall be recorded at minimum in-
through (f) for each frequency.
tervals of 10 minutes. If necessary, adjustments
d. Results. The data sheet shall show the maxi-
to the load, voltage and frequency may be made to
mum and minimum frequencies attained at rated load,
maintain rated load at rated voltage and rated fre-
the maximum and minimum attainable frequencies at
quency. However, adjustments available to the
7-11
