- #1
eli_lied
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Can anyone tell me how to determine the force necessary to spin an alternator at the rated RPM?
Force necessary to spin an alternator at the rated RPM?
- Thread starter eli_lied
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In summary, the force necessary to spin an alternator at the rated RPM depends on the specific properties of the alternator, such as friction and electrical load. However, for a 6000 watt alternator operating at 3600 RPM, the torque required would be approximately 15.9 Newton-meters. It is also important to consider the efficiency of the alternator, as it may require more power to turn it than the calculated horsepower suggests. It is recommended to consult a detailed source or supplier for specific information on alternators.
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HallsofIvy
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No, because that depends upon properties of the specific alternator. In particular, the friction in the alternator itself and the time in which it is brought up to that RPM.eli_lied said:
- #3
russ_watters
Mentor
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...and the electrical load on the alternator.
- #4
eli_lied
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ok hypotheically then, let's say it's a 6000 watt generator head taken from a portable home backup generator. if i have 6400lbs-ft of constant force and the generator head operates at either 3600 rpm or 1800 rpm...without knowing the specific details such as mass(approx. 60-80lbs of rotational parts) or friction, is it possible to determine the force necessary? also does anyone know of a website that offers detailed information on alternators and/or suppliers that I could purchase one from?
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Ranger Mike
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Bob S
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Torque (Newton-meters) in angular rotation is the equivalent to force (Newtons) in linear motion. For an alternator, the power output (watts) is the product of the angular force times the angular speed. Specifically
T x 2 pi RPM/60 = W watts, where the torque T is in Newton-meters.
So for a 6000 watt alternator output (at 100% efficiency) at 3600 RPM, the torque is
T = 60 W/ 2 pi RPM = 15.9 Newton-meters.
6000 watts (at 100% efficiency) is equal to 8.04 HP
Bob S
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Ranger Mike
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be advised that in the real world alternators are 40% efficient which is why there is a difference between calculated HP and actual parasitic HP required to turn the Alt.
1. What is the force required to spin an alternator at its rated RPM?
The force required to spin an alternator at its rated RPM depends on various factors such as the size and weight of the alternator, the type of bearings used, and the efficiency of the alternator. Generally, the force required is proportional to the size and weight of the alternator, and is more for larger and heavier alternators.
2. How do you calculate the force necessary to spin an alternator at its rated RPM?
To calculate the force necessary to spin an alternator at its rated RPM, you will need to know the torque and rotational speed of the alternator. The force can be calculated by multiplying the torque by the rotational speed. Torque is typically measured in Newton-meters (Nm) and rotational speed is measured in revolutions per minute (RPM).
3. Can the force required to spin an alternator at its rated RPM change?
Yes, the force required to spin an alternator at its rated RPM can change depending on various factors. For example, if the alternator is damaged or worn out, it may require more force to spin at the rated RPM. Additionally, changes in the environment, such as temperature and humidity, can also affect the force required.
4. Why is it important to know the force necessary to spin an alternator at its rated RPM?
It is important to know the force necessary to spin an alternator at its rated RPM as it helps in selecting the right size and type of motor or engine to power the alternator. It also ensures that the alternator is operating efficiently and is not being over or underpowered.
5. How can the force required to spin an alternator at its rated RPM be reduced?
The force required to spin an alternator at its rated RPM can be reduced by using high-quality bearings, keeping the alternator well-maintained and properly lubricated, and avoiding overloading the alternator. Additionally, using a larger drive pulley or reducing the load on the alternator can also reduce the force required to spin it at its rated RPM.
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