Diesel Generators And Power Factor

Good question.

In theory no. The kW output of the engine would be the same.

However, the reduced current output of the alternator would give less internal losses. Thus a lower kW draw from the engine.

However however, since a reasonable size alternator is better than 90% efficient, this will not equate to a large difference.

Note that since genset output is traditionally quoted as "kVA @ 0.8pf", running at 0.7 is compromising your current draw.

The rated out put of Alternator are at 0.8 p.f

The connected load at improved p.f should not exceed the rated AMP of Alternator.

Dear Nezz,

Answer for your Question is No fuel saving is possible.If you operate the engine at higher power factor the full load current rating of Alternator will be reducing since the engine designed for a particular Power Factor.

In spite of what others are saying... The better PF will reduce the currents in the generator (and other circuits) and have an effect on the fuel consumption.

1. All electrical circuits have resistance ( including the generator windings)

2. Current through any resistance causes heat. W = I² R (this is Gods Law)

3. Heat is energy and energy is power. Your Generator is supplying the power.

4. The power comes from the fuel.

Depending on the size and design of the machine, the energy savings may be large or insignificant.

What I am saying is that the RVA (I + _jx ) currents are useless for extracting power but Resistance losses (due to reactive currents) must be generated by the generator.

Snakers

There is a way to get more fuel economy out of your generator.

Schaeffer Manufacturing has a fuel additive that typically reduces fuel consumption by 10%. Their engine oil should also contribute up to 5% savings.

Call me for info if you like: 216-401-1845 ( lubricants@rgreenwald.com )

PF correction does not save fuel. Reactive power is not watts, and the engine power (fuel consumption) demand is ONLY related to watts. Correcting power factor reduces amps, and that will save you some generator (alternator) insulation breakdown in the long term (less heat rise).

Hope this saves you a ton of money NOT buying power factor correction items. I am 100% sure of this.