4024... [RE-wrenches]

[R. Sparks Scott]

	Todd and All;

	I'm going to weigh in on this just a little.
	One thing that hasn't been discussed is the method engine driven
generators use to regulate the frequency-vs.-output voltage. There may be
several ways of doing this:
	Less expensive units may simply have an electromechanical solenoid/lever
connection to the carburetor. The voltage is a pretty good indication of
load. When the voltage droops due to heavy load, the electromagnet slacks,
giving the engine more fuel. light or no load, the solenoid backs off on
the throttle.
	More likely in modern generator sets, there will be a frequency-to-voltage
converter/solenoid driver circuit that performs the same function. How
sophisticated the circuit is, and how well it regulates the engine RPM over
a range of loads is a function of how well it was designed, calibrated, and
implemented.
	As RPM%=Hz output, using a tachometer circuit to actuate the throttle
would be another way to regulate frequency.
	Turn-of-the century (1900's that is) speed regulation would be
accomplished by flyball centrifugal governors. Maybe a modern equivalent is
still used today?
	The point of all this is to say that few inexpensive generators have
circuitry to control the engine RPM as a function of output load, but
depend on detection of RPM to know if they are running at the right
speed/throttle position.
	Voltage output can be controlled by changing the intensity of the field
circuit, by whatever means, this is also load-dependent.
	What we also need to keep in mind is *waveform distortion*. Total Harmonic
Distortion, commutation/slip ring spikes, and general hash on the AC output
may be causing the Trace to decide that the voltage/frequency is
out-of-range. Don't know if the Trace looks for zero-crossover on the AC 2
input, but a lightly loaded genset might not be clean enough without some
power being drawn by other loads to keep the SW happy.
	Yet more trouble might come from phase variations. The lightly loaded
Trace uses fewer 'steps' to produce the battery charging output (yes, those
'steps' come into play when the current goes both directions, that's how
the charge current is regulated). This might be inducing 'ringing' or some
other anomalous AC circuit dynamics into the field/stator circuit. I'd
suggest trying a resonant line conditioner between the generator and the
Trace just to see what happens. If your current range is manageable, a
plain-old Tripp Lite line conditioner that is used for computer
installations might illuminate the situation.
	AC circuits produce a lot of complicated factors, including reactance,
vectors, phase relationships, and a lot more. Troubleshooting them is a
real engineering challenge. Don't give up, keep trying different stuff
until you see results, or at least new and different symptoms.

	-S

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