Small Engine Troubleshooting Problems? Ask a Mechanic Now.
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What is the serial number of your genset?
I needed this, as there are 4 different schematics for the EB3500, and they are serial number dependent.
This is a fairly basic set as far as generators go, and there are not many parts that can go bad.
What I need you to do is to connect a voltmeter to the receptacle and monitor the voltage while the set is running.
With a light load on the set, if the voltage is fluctuating more than about 5 volts, but the engine is not changing speed, it would indicate that the AVR is going bad.
If the voltage fluctuation is not more than 5V, it may indicate a possible issue in the stator, but this is highly unlikely. Let me know if this is the case.
That voltage is way too high.
I am very concerned about the fact that the voltage drops when the engine speeds up and rises when the engine slows down - this is just the opposite of what should happen.
This is still most likely a bad AVR, but right now what really needs to be done is to measure the output frequency to verify engine speed.
If the engine is not running at the proper speed, it will not do much good to test anything else.
Do you have, or have access to, a frequency meter?
If the engine speed is what it should be, the AVR needs to be replaced.
If the engine speed is not what it should be, this needs to be taken care of first.
I don't have a frequency meter. The genset has been running for more than an hour now. the voltage has been staying at 118 to 120. It did that 168 to 172 volts for about 2 mins. But the RPMs did drop ever so, so slightly. It is so slight that you can just bearing hear the difference. I am some what mechanicaly enclined. Maybe the average person may not hear the difference. But the voltage dropped back to 118 to 120. It may do this voltage thing in a 4 to 6 hr. time frame about 3 to 4 times. Where is the AVR on the genset?
The 118-120 range is perfectly normal - in fact, maybe just a sliver low if there is no load on the set.
The AVR is located under the end cover of the genset.
It is a kidney shaped device with 6 wires going to it.
That's it - the Automatic Voltage Regulator.