Documentation discrepancy

[Mike Busutil]

AMMETER :book:

 

On page 92 of the P-51 flight manual it say's:

"the generator provides power to the electrical system when the speed is above approximately 1200 RPM."

 

On page 42 it says:

"The electrical system runs off the battery until the engine reaches 1500-1700 RPM, when the generator is cut in by the voltage regulator."

 

When I test it I am seeing the Ammeter start to read once the RPM reaches approx 1500.

 

Is this a valid discrepancy?

Edited September 25, 2013 by Mike Busutil

[Der_Fred]

I don't know the P51 electrical system, but following the logic of generators...

 

Once the engine is running the generator should be powering the system.

This I'd imagine depends on how much power is required by the electrical system (what devices you have turned on), so the point where the generator takes over could be anywhere between the two limits - I don't think this variability is modeled.

 

A point to consider is that the battery cannot last forever without the generator, and generators should be charging the battery, and powering the system at idle speed.

[sobek]

I don't know the P51 electrical system, but following the logic of generators...

 

Once the engine is running the generator should be powering the system.

This I'd imagine depends on how much power is required by the electrical system (what devices you have turned on), so the point where the generator takes over could be anywhere between the two limits - I don't think this variability is modeled.

 

It also depends on the battery voltage, which in turn depends on ambient temperature. The battery model is quite sophisticated, so i believe that the generator switching voltage might be variable as well. You can try it out, just start her up in cold weather and observe if the generator is switched on earlier.

 

A point to consider is that the battery cannot last forever without the generator, and generators should be charging the battery, and powering the system at idle speed.

 

This is not the case in the real airplane so why should it in the sim?