Can a 12V DC Motor Efficiently Power a 120 Amps Alternator at 2100 RPM?

[bikram]

Is it possible/meaningful to use a 12V DC motor to run a 120 amps. Alternator at 2100 rpm ? If yes, what kind of DC Motor should be used (RPM/Watts/HorsePower)

 

[russ_watters]

Sure it is possible, but I don't know why you would do it. The motor just needs to be about 20% larger than the alternator to account for inefficiency losses. You didn't say what the voltage of the alternator was, but if it is a 120 A, 12V AC alternator, then what you are doing is converting 12V DC to 12V AC with a 20% loss. So figure on a 150A motor to run it (1800W).

 

[oswaler]

Yes, it is possible to use a 12V DC motor to run a 120 amps alternator at 2100 rpm. However, the type of DC motor needed will depend on several factors such as the efficiency of the motor, the load on the alternator, and the desired power output.

In order to run a 120 amps alternator, the DC motor should have a minimum power output of 1440 watts (120 amps x 12 volts). The RPM of the DC motor should be at least 2100 rpm to match the speed of the alternator. The horsepower of the motor will depend on the efficiency of the motor and the load on the alternator.

It is important to choose a DC motor with a high efficiency rating to ensure that it can handle the load of the alternator and run at the required speed. A brushless DC motor would be a good choice as it has a higher efficiency compared to brushed DC motors.

In summary, it is possible to use a 12V DC motor to run a 120 amps alternator at 2100 rpm, but the type of DC motor needed will depend on factors such as efficiency, load, and power output. It is important to carefully consider these factors when selecting a DC motor for this application.