
FIGURE 3
The PM300 has the roll-off point preset to 58 Hz in the 60 Hz mode and 48 Hz in the 50 Hz
mode. To change the roll-off point, adjust engine speed to the desired rated speed. (50 or 60 Hz).
Set the voltage to the desired setting at rated speed. Adjust engine speed to the desired roll-off
point. Turn the potentiometer counterclockwise until the voltage starts to drop off. Then adjust
the potentiometer clockwise until the voltage returns to rated voltage. Re-adjust engine speed to
rated speed.
STARTUP PROCEDURE
PRELIMINARY SET-UP
Ensure the voltage regulator is correctly connected to the generator. Refer to the specific
connection diagram supplied with the generator.
Set the regulator voltage adjust to full counter-clockwise (minimum voltage level).
Set the remote voltage adjust (if used) to the center position.
Set the stability control full clockwise (maximum stability level).
Connect the positive lead of a 100 V D.C. voltmeter to Fl and the negative lead of the voltmeter
to F2 or use an appropriate AC voltmeter on the generator output leads.
SYSTEM START-UP
Start and run the generator at no load and rated speed. The generator voltage should build up to a
minimum level. (Actual level is dependent upon connection). If it does not build up, refer to field
flashing section in generator manual.
Slowly adjust the voltage control until the generator voltage reaches the nominal value. If used,
adjust the remote voltage rheostat to set the generator voltage to the exact value desired.
Turn the stability adjust counter-clockwise until instability is shown on either of the voltmeters
mentioned in the “PRELIMINARY SET-UP” section. With the system operating in an unstable
condition, slowly adjust the stability control clockwise until generator stability is reached.
Interrupt regulator power for a short time (approximately 1-2 seconds).
If the generator remains stable, no further adjustment is necessary. If the generator does not
remain stable, increase the stability slightly and interrupt regulator power again.
This procedure should be repeated until system stability is reached and maintained.