02-03-2023, 08:21 PM
It is common for a small generator to deliver less current than it is advertised to be able to. Brochure units are frequently different to engineering units, especially at the low $$ end of the product line up. Many/most generators are advertised as XX.xx KW. This is it's surge rating, and the lower the price the further this rating gets ahead of actual usable watts. Rather like the advertising amplifier power in economy audio products. In extremes, the amplifier can only deliver that power level (on a cold day) for one forward stroke of the speaker and one backward stroke. Then it must rest or perish. Not much music in music power.
Much as a car must accelerate through the gear range, a refrigerator has a fairly 'reluctant to accelerate' rotating mass. Older fridges are more current hungry on start-up. When the fridge starts, everything in it is stationary, and the generator is spinning. The motor represents a short circuit and will swallow a great deal of power from the generator. IF the generator is built with good materials in adequate quantities and with efficient magnetic as well as electrical circuits it will attempt to deliver a great deal of current, this makes the generator slow down. An economy generator will be a bit short of current carrying capacity, so its ability to deliver current into a load is limited as is the motor's ability to maintain the rated speed. this limits the voltage out, restricting the ability of the fridge to accelerate. The generator keeps slowing down, making its ability to spin up the refrigerator dubious, more heat than work at this stage and something has to give. Hopefully, a circuit breaker will do it's job and save the windings from dying. All these effects make it unlikely that an economy generator can do what it claims unless you have a bit of luck.
Just BTW, the 2.5 brochure horsepower in theory represents 3.35 KW. Even in the brochure, that only delivers 1.1 KW (For a VERY limited time.) Not a sparkling model of efficiency even using their own optimistic figures.
A kitten is cheaper than a horse, but it doesn't pull a plough too well. Generators, especially of toaster shop brands, are a minefield for the unwary. Price is no indicator, some real junk has a very flash exterior and expertly crafted sales materials.. As far as I know, even if it fell off a truck, their are no cheap generators that offer value for their rated load performance. Some may last several hours if you keep fresh fuel in them, avoid bargain oil, change the oil earlier than the manufacturers state. (Manufacturers oil change intervals are dictated by the EPA, nothing to do with optimised equipment life.
At least generator lessons can prepare you for adventures with off grid power in general. Caveat Emptor is more relevant for us than it was for Caesar.
Much as a car must accelerate through the gear range, a refrigerator has a fairly 'reluctant to accelerate' rotating mass. Older fridges are more current hungry on start-up. When the fridge starts, everything in it is stationary, and the generator is spinning. The motor represents a short circuit and will swallow a great deal of power from the generator. IF the generator is built with good materials in adequate quantities and with efficient magnetic as well as electrical circuits it will attempt to deliver a great deal of current, this makes the generator slow down. An economy generator will be a bit short of current carrying capacity, so its ability to deliver current into a load is limited as is the motor's ability to maintain the rated speed. this limits the voltage out, restricting the ability of the fridge to accelerate. The generator keeps slowing down, making its ability to spin up the refrigerator dubious, more heat than work at this stage and something has to give. Hopefully, a circuit breaker will do it's job and save the windings from dying. All these effects make it unlikely that an economy generator can do what it claims unless you have a bit of luck.
Just BTW, the 2.5 brochure horsepower in theory represents 3.35 KW. Even in the brochure, that only delivers 1.1 KW (For a VERY limited time.) Not a sparkling model of efficiency even using their own optimistic figures.
A kitten is cheaper than a horse, but it doesn't pull a plough too well. Generators, especially of toaster shop brands, are a minefield for the unwary. Price is no indicator, some real junk has a very flash exterior and expertly crafted sales materials.. As far as I know, even if it fell off a truck, their are no cheap generators that offer value for their rated load performance. Some may last several hours if you keep fresh fuel in them, avoid bargain oil, change the oil earlier than the manufacturers state. (Manufacturers oil change intervals are dictated by the EPA, nothing to do with optimised equipment life.
At least generator lessons can prepare you for adventures with off grid power in general. Caveat Emptor is more relevant for us than it was for Caesar.
Entropy is not what
it used to be.