Generac Power Systems 53187 - Manual (Page 55)

PARTI
THE REVOLVING FIELD AC GENERATOR
Voltage Regulator Adjustment (Contin­
ued):
SECTION 1.9
I
OPERATIONAL TESTS & ADJUSTMENTS
i
0
VOLTAGE
REGULATOR
“ +
2 6 1 4 11 22
0 0 0 0 0 0
Figure 2. Voltage Regulator (Units w ith 10" Stator)
UNITS W ITH 15 INCH STATOR:
The voltage regulator used on NP series units w ith
15 inch stator is show n in Figure 4. To adjust the
regulator, proceed as follow s:
1. Gain access to the voltage regulator in the generator
control panel.
2. If a new replacem ent regulator is being installed,
locate Sw itch ‘SW r on the regulator circuit board. Set
the sw itch to Position “2". Position "1“ is used only for
brushless generators.
3. Connect an accurate AC voltm eter and frequency
m eter to the generator’s AC output leads.
4. W ith unit shut dow n, set the voltage regulator poten­
tiom eters as follow s:
a. Turn the “Voltage Adjust’' pot fully counterclock­
w ise.
b. Set "Gain" to its centered or m id-position.
c. Set "Stability" to its centered or m id-position.
d. Do NOT adjust the ’’Underfrequency Adjust" pot.
5. If so equipped, set the control panel’s voltage adjust
pot to its centered or m id-position.
6. Turn OFF ail electrical loads. Startup and initial
adjustm ents w ill be accom plished under a "no-load"
condition.
7. Start the engine, let it stabilize and w arm up at
no-load.
8. Check the reading on the frequency m eter.
a. Frequency shouid be 60.5-63.5 Hertz.
b. If necessary, adjust the engine governor to obtain
a no-load frequency reading as ciose to 62 Hertz as
possible. See adjustm ent procedure for governor.
c. Do NOT' proceed until governor is properly ad­
justed and frequency reading is correct.
9. Check the lam ps (LED’s) on the voltage regulator.
All lam ps should be ON. If any lam p is OUT, see
appropriate troubleshooting section.
10. Turn the reguiator's "Voltage Adjust" pot to obtain
a line-to-line voltage of 242-254 volts; a line-to-neutral
voltage of 121 -127 volts. Try to get the voltage as close
as possible to 124 volts (line-to-neutral): or 248 volts
(line-to-line).
11. If the red "Regulator" lam p is flashing, turn the
"Stability" pot either direction until the flashing stops.
12. Apply an electrical load and check engine speed
recovery.
a. Adjust the "Underfrequency Adjust" counterclock­
w ise to unload the unit and reduce load voltage w hile
the engine recovers.
b. For flat regulation (no voltage decrease as fre­
quency drops), turn the ’’Underfrequency Adjust"
fully clockw ise. Set point for this adjustm ent is 62
Hertz (counterclockw ise) to 52 Hertz (clockw ise).
c. To obtain a constant voltage reduction as fre­
quency drops, set "Underfrequency Adjust" fully
counterclockw ise.
13. W ith electrical load still applied, check the "Regu­
lator" lam p for flashing. If lam p is flashing, adjust the
"Stability" pot until flashing stops.
14. If better response is needed, adjust the "Gain" pot
clockw ise as needed. Then, if needed, correct for insta­
bility by adjusting the "Stability" pot.