TM 5-6115-593-34
NAVFAC P-8-631-34
TO-35C2-3-463-2
not necessary to record line-to-line voltages). Each load condition shall be applied to the generator
set in one step at the end of the short-term stability period for the previous load condition. The load
conditions are:
1.
No load
2.
1/2 rated load
3.
No load
4.
1/2 rated load
5.
No load
6.
1/2 rated load
7.
No load
8.
1/2 rated load
9.
Rated load
10.
1/2 rated load
11.
Rated load
12.
1/2 rated load
13.
Rated load
14.
1/2 rated load
15.
Rated load
16.
1/4 rated load
17.
3/4 rated load
18.
1/4 rated load
19.
3/4 rated load
20.
1/2 rated load
21.
3/4 rated load
22.
1/4 rated load
23.
3/4 rated load
(d)
Repeat (a) through (c) for all voltage connection(s) and frequency(ies).
d.
Results.
(1)
Prepare a chart giving for each load change the momentary overshoot or undershoot and the recovery
time. For each constant load, give the maximum voltage variation.
(2)
Referring to figure 16-1, begin by determining the observed (B) and steady-state (D) voltage bandwidths.
(a)
Mark numerically the stabilizations occurring after each load change, starting with the stabilization
obtained before the first load change.
(b) Determine the observed voltage bandwidth (B) by marking the maximum trace excursion and
minimum trace excursion in the stabilized portion. Draw two lines parallel to the axis of chart movement,
one each passing through these maximum and minimum trace excursions respectively.
(c) Draw a line (C) parallel to and equidistant from the edges of the observed voltage bandwidth.
Determined in (b) above.
(d) Using the rated voltage of the generator and given requirements of table 16-1, calculate the
steadystate voltage bandwidth (D). Draw this steady-state voltage bandwidth as two parallel lines,
parallel to and equidistant from the median (C) at the observed voltage bandwidth.
(3)
To determine the maximum voltage variation at constant load:
(a) One-half the observed voltage bandwidth (B) is the plus or minus value of voltage deviation at
constant load.
16-10
