Voltage instability will be most evident immedi-
ately following application or removal of the
(b) Turn screw on R15 (or R16) clockwise to
(c) Turn screw on R15 (or R16) clockwise two
(2) Operate Generator Set at 120 volts, single phase
load at 25%, 50%, 75% and 100% load.
(3) If L1 to L3 voltage deviates more than 5% over
the load range, voltage regulator is defective.
b. Inspect (see figure 6-3).
(1) Drop the control box panel (28) by loosening
fasteners (9) to expose the voltage regulator (39).
(2) Visually inspect the voltage regulator for poor
connection or burned or open components or cracked circuit
(1) Tag and disconnect harness leads to voltage reg-
(2) Remove nuts (38) attaching voltage regulator
from control box (57) and remove voltage regulator.
d. Test, Bench (see figure 6-4).
(1) Connect ac voltage regulator to test circuit and
test as shown in figure 6-4. Transformers Tl and T2 are
located in the control cubicle (see figure 6-3, items 34 and
37) and may be disconnected and used for this test.