Alternator and Electrical System

[Ventucky Red]

Quick question... and help me settle a bet... with regards to the alternators when I start flipping stuff on avionics, lights, etc... will this cause a reduction on the engine performance as it need to push a little harder to keep up?

I always thought that the alternator was going to be pushing out 28 ~ 29.5 volts with the alternators rated AMP rating regardless of what appliances I appliances on line..

Thanks

 

[Clark1961]

No

 

[tspear]

Technically yes. The power has to come from somewhere.
However, I dare you to try and measure it. The weight of the coffee you grabbed at Starbucks probably has a bigger effect on the plane performance.

Tim

 

[Axtel4]

A 100 amp alternator at 14v will take about 3 hp.


1 hp = 746 watts

14v @ 100 amps = 1400 watts

1400 / 746 = 1.87 hp

Give an alternator is about 60% efficient the net HP used is 3.11 hp
1.87/.6 = 3.11 hp

 

[Clark1961]

Quick question... and help me settle a bet... with regards to the alternators when I start flipping stuff on avionics, lights, etc... will this cause a reduction on the engine performance as it need to push a little harder to keep up?

I always thought that the alternator was going to be pushing out 28 ~ 29.5 volts with the alternators rated AMP rating regardless of what appliances I appliances on line..

Thanks

As an aside the job of the voltage regulator is to "manage" the output of the alternator. The voltage regulator controls the stator's magnetic field which in turn drives the output from the stator. The result is the alternator only produces the power required by the electrical system. The electrical system loads vary with time of course and the alternator rarely operates at maximum capacity.

 

[Norman]

As an aside the job of the voltage regulator is to "manage" the output of the alternator. The voltage regulator controls the ROTOR's magnetic field which in turn drives the output from the stator. The result is the alternator only produces the power required by the electrical system. The electrical system loads vary with time of course and the alternator rarely operates at maximum capacity.

FTFY.

 

[Clark1961]

FTFY.

thank you