by KE4AVB » Thu Nov 08, 2018 5:55 am
Especially since 220 vac usually can only operate 5hp max electric motor. Now if you go to 3 ph then there are more powerful motors. I have an air compressor that is rated at 5 hp but the new motor is rated only 3 hp and it still draws the same current at startup. More than my 8Kw surge generator can startup under air load even the generator's has 5.5 Kw running capacity. Now the new is rated as a compressor motor.
Yes the old gasoline small engine hp were all over the place as companies use various ratings and could get by as the engine only had to produce 85% gross of the declared rated power and torque. Now the new SAE J1940 rating requirement that went into effect October 1, 2013 that changed to 95%. SAE (Society of Automotive Engineers) has also stated that the engine manufacturer must disclose the rpm for rating and with the GROSS (SAEJ1995) or NET (SAEJ1349) horsepower. (SAE) J1940 based on gross output testing performed according to SAE J1995 without the air cleaner and muffler. Actual engine power and torque can be lower and affected by accessories (air cleaner, exhaust, charging, cooling, fuel pump, etc.), application, engine speed, ambient operating conditions, (temperature, humidity and altitude) and other factors. This J1940 / J1995 rating provides consistent measurement to customers who may want to control the intake and exhaust features of the engine. Some manufactures like Kohler may only test 10 engines off the assembly line and average the output figures and other use minimum found during such tests. Otherwords some engines maybe as much as 5% than the stated gross output figures just depend how the manufacture arrived at their output numbers and still be legal. It all comes down actually comparing the engines to each other in real life for your particular operation with all the accessories (and manufactures do call air filters and mufflers accessories) in place.
The truest measure of society is the how it treats its elderly, its pets, and its prisoners.