ericlemmon
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Re: 3000W Chinese Gensets Info.
GETTING FULL POWER FROM A C46535 GENERATOR: Based upon the generally favorable reports on this and other sites, I bought a Champion Model C46535 generator from Kragen Auto Parts, for $299. Its serial number (stamped on the side of the engine block) is 051006822. As an electrical power engineer, it's my habit to check over any electrical device for loose connections, before applying power to it. In this case, it was good that I did, because all three of the terminal nuts on the generator were loose, and one nut was backed off almost two turns. I should mention that my generator was factory-sealed in its original shipping box, so I attribute this oversight to poor quality control. Using an 8mm nut runner, I quickly tightened all terminals. Perhaps I should not that these terminals are exposed when you remove the two screws on the louvered end cap from the generator. My generator has one NEMA L14-30R twist-lock receptacle for 120/240 VAC loads, and two NEMA 5-20R duplex receptacles (four outlers total) for 120 VAC loads. The owner's manual states that you need a NEMA L5-30P plug, which is not supplied, but such a plug will not mate with the L14-30R receptacle! As others have determined, one cannot draw the full 3500 watts from this generator using any normal connection. However, that's exactly what I want to do- and I'll get there soon. In the existing configuration, the generator's two output windings are connected so that one 120 VAC winding is protected by a 20 ampere circuit breaker and the other, identical, winding is protected by a 15 ampere circuit breaker. In my generator, the left duplex receptacle is limited to 15A, and the right duplex receptacle is limited to 20A. The L14-30R receptacle is essentially useless, because it is a 30 ampere device that is limited to 20A on one side and 15A on the other side. This is technically a violation of the National Electrical Code which requires that receptacles be wired to branch circuits which match the receptacle rating. To get the full generator rating at 120 VAC, I rewired the armature windings so that they are in parallel and properly phased. The automatic voltage regulator senses only one of the output windings, so I was pretty certain that paralleling the armature windings would have no effect. I was right. The output voltage can be adjusted with a tiny screw that peeks out from the potting compound in the AVR unit, but I have not felt the need to tweak it- yet. I pulled out all of the original wiring harness, along with the original circuit breakers. I then ran #10 AWG stranded THWN wire from the now-rewired terminal strip on the generator to a new 30A circuit breaker. The load side of this breaker then feeds a new NEMA L5-30R twist-lock receptacle that replaces the original L14-30R receptacle. I then ran a wire back to a new 20A circuit breaker that is downstream of the 30A breaker, which then feeds the two 5-20R duplex receptacles. I did not connect the voltmeter, since I have a generator transfer panel that is metered. If I were planning to use this generator to power an RV, I could have installed a standard 30 ampere "TT" receptacle in place of the L5-30R receptacle, but the TT receptacle requires a larger diameter hole. There are two limits to the amount of electrical power you can get out of any generator. The available horsepower of the prime mover puts an absolute cap on the output, regardless of the voltage used. Based upon the 6.5 HP engine and a reasonable efficiency of 80%, I would expect the engine to falter when the load exceeds about 3800 watts. The inertia of the rotating mass (generator and engine) will allow spurts well above that figure, but the flywheel effect only helps for a few seconds. The other limitation is electrical- the size of wire used in the armature windings. The more current drawn through these wires, the hotter they get. In most of the applications to which this generator might be used, only one of the windings will be loaded. That means that no more than 2400 watts is available ( 120 volts times 20 amperes). Since I only have a 120 VAC load to feed, I now have both windings in parallel which gives me a maximum available capacity of 3600 watts (120 volts times 30 amperes). I will post instructions for accomplishing this modification, if there is sufficient interest351Views0likes0Comments
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