3000W Chinese Gensets Info.

Salvo wrote:
Found why my generator smelled of gas. It appears the rubber gasket around the gas cap doesn't make a good seal. The gas smell is coming from the cap. Not sure, if you turn the tank upside down, does gas leak out?

Did some temperature testing. The Yamaha 2800 does get toasty. I loaded the gen with a 1500W heater.

The ambient temp = 54 F.
The hottest spot, close to the spark plug = 117 F.
The hot air being blown out the side = 104 F.

If I want to run the gen at 100 F ambient, then the temperature measurements get increased by (100-54)= 46 F.

That means the hottest spot = 117 + 46 = 163 F, and the hot air temp becomes 150 F.

That seems cutting it a bit close to install a 165 F thermal switch; even for the air temp location with a 15 F margin. What does that tell us? If you got a 165 F thermal switch, don't run gen when it's 100 F outside? How much safety margin do you guys have?

Sal

While your calculations may appear accurate, at higher ambient temperatures the ability to remove heat from the generator is reduced. Thus, it will run even hotter than your calculations at 100 degrees F outside.

Load is another factor. The harder the generator is working, the more heat it will produce.

I do not have a temperature recomendation from a manufacturer. My concern is not for the engine, as they can withstand air temperatures well over 200 degres F if you use a top quality oil.

I derived at the 194 degree F rating for the type of wire (THWN) used in the genny as the absolute limit. I prefer to drop back to the 167 degree F rating for THWN to be on the safe side. Also consider that as a wire gets hotter, resistance goes up. For example, #12 AWG copper is rated at 617 feet per ohm at 77 degrees, then rises to 534 feet per ohm at 149 degrees. That may not sound like much, but when you consider the amount of copper wire in the generator windings it begins to make a difference.

BTW - all the power ratings and performance data on the Chinese 3,000 watt class open frame generators is given at a maximum ambient temperature of 85 degrees F. Thus, the 3,500 watt output rating of a 36540 CPE is not realistic at 100 degrees. Again, by my seat-of-the-pants calculations you should reduce power by 2% for every degree above 85. So, at 100 dgrees you should back off on power (load) at least 30%, or to no more than 2,450 watts for a 3,500 watt rated genny.

Once more - these are MY calculations, not the manufacturer's. It is what I have determined to be safe operating values. Some one else may have a different belief.

On the fuel tank..... most all of these gennys, my Kipor included, must have a vented cap to work. If there is no vent, gas flow will stop. On the Chinese 3,000 watt class open frame models the tank WILL leak if sloshed around. The fix is to NOT fill it completely full so the baffel in the tank neck will keep fuel from splashing out. On my Kipor, there is a open and closed valve for the cap vent. Thus, it can be sealed for transport.