P-9-TM-457-35
T.O. 35 C2-3-442-2
TM-07464A-35 TM 5-6115-457-34
and 4, at 60-hertz or 400 hertz with no
not stability the generator, then reduce
load. When adjustment will not provide a
frequency gain R18 to a stable region and
zero reading across test points 1 and 2,
optimize generator stability and perform-
then adjust for a minimum reading.
ance by adjusting potentiometer R1 6.
NOTE
(h) Connect a 0 to 10 vdc volt-
meter between test jacks A and B and check
for a normal DC voltage reading of appro-
For long term generator stability,
ximately 4 to 6 volts. Adjust potentiometer
frequency gain should be reduced to
a point where the system is not on
R12 to obtain proper voltage readings.
the edge of instability.
(i) To achieve optimum transient
When a steady state frequency of full load
performance, adjust the load measurement
gain control potentiometer R15. Adjust-
is slightly lower than no load steady state
ment of R15 to a full clockwise rotation
frequency (droop), re-adjust potentiometers
position provides maximum load measure-
R12, R14, or R18 slightly. Rotating po-
ment gain.
tentiometer R18 full clockwise for all
operating conditions will often eliminate
droop, and under certain circumstances,
(j) To obtain optimum perform-
ance, adjust potentiometer R18 to a maxi-
adjusting potentiometer R14 for voltage
mum clockwise rotation position and poten-
reading above zero at test jacks 3 and 4 will
tiometer R16 to a maximum counterclock-
also eliminate droop. A slight readjust-
wise rotation position without causing an
ment of the magamp bias lever potentiom-
oscillation to develop for any position set-
eter R12 will provide isochronous operation
ting of potentiometer R15. The value of
under certain conditions.
capacitor C 1 (referred to in precise mode
II relay box schematic electronic compon-
2. Parallel Operation Alignment and
ent assembly A6) will also affect transient
Adjustment
frequency response. Small values of capa-
citance will give faster transient frequency
(a) With the generator operating
response; however, if the capacitance of
under no load, disconnect electrical con-
C 1 is too small, the system will oscillate.
nector J 17 at electric governor control
unit. Use a dc voltmeter and check for zero
(k) For any position of poten-
voltage between pins G and J (pin G is
tiometer R18, there is an optimum position
positive).
setting for potentiometer R16. To improve
transient performance even further, rotate
(b) With the DC voltmeter connect
potentiometer R18 in a clockwise direction.
across pins G and J of connector J17, apply
If a hunt develops, re-adjust potentiometer
full load to generator set and adjust the real
R16 to achieve stability. If, however, no
load sharing potentiometer R12 in the pre-
hunting condition develops, then apply and
cise relay box or the mode II relay box
remove the load and observe stability of
through its full range. The dc voltmeter
generator under such transient conditions,
should indicate between 5 and 10 volts dc.
while continuing to adjust potentiometer
Note and record the exact range of dc volt-
R18 in a clockwise direction. when a po-
age available on set number one by adjust-
tentiometer R18 has been adjusted to a point
ing the real load sharing potentiometer.
where adjustment of potentiometer R16 will
6-181
Change 3
