DIAGRAMS & DRAWINGS
42 Copyright © 2009 Mastervolt / May 2009 / Whisper 7/9.5/15/20 Ultra for mobile applications / US
4.10 WIRING DIAGRAM ELECTRONIC GOVERNOR (STANDARD FOR WHISPER 7, 9.5 AND 15 ULTRA)
Figure 47: Electronic governer.
In addition to the mechanical governor, the Whisper 7, 9.5
and 15 Ultra are standard equipped with an electronic
governor. A governor keeps the speed (RPM=Rotations
Per Minute) of the engine at a fixed value. The RPM of the
engine correlates with the frequency of the electrical
output (1800 RPM =60 Hz) of the alternator.
Under full load the RPM of the Whisper models that has
only a mechanical governor can drop 75 RPM (=2.5 Hz) at
full load and will go further down or collapse when further
loaded. However the engines with the electronic governor
will keep the RPM and frequency at the set value. As the
voltage is related to the frequency, the voltage will be
more stable as well.
The RPM represents power and the alternator performs
better as well on a higher speed. Whisper models with an
electronic governor will bring more power.
So the electronic governor offers three advantages: a
more stable frequency and voltage and more power.
The electronic governor system contains two parts:
1 The actuator controls the engine speed. This actuator
replaces the standard hold solenoid that is on all other
mechanical controlled Whisper engines. The actuator
controls the RPM directly on the fuel rack inside the
fuel pump without levers and other mechanical
transmissions.
2 A microprocessor keeps the speed at the set value by
controlling the actuator. The microprocessor is
programmed at the Mastervolt factory and many
parameters are set to perform well. It should not be
necessary to make adjustments. When adjustments
are necessary this can only be done with the help of
an interface to a computer and special software to get
access to the microprocessor.
The Mastervolt electronic governor does not need a pickup
device in the flywheel housing that counts the passing
tooth of the flywheel and determines the exact RPM of the
engine, because the processor uses the 60 Hz of the AC
output voltage as a reference.