Generator question

[just the cowboy]

I know when a generator sits for a long time unused sometime the field needs to be re-excited. An old-timer told me the other day you can plug a 1/2" drill into the outlet, squeeze the trigger and carefully spin the chuck backwards. They said just be careful because the drill will start. They said that the field from the drill will excite it. Anyone hear of this I didn't in forty years

 

[zbang]

I haven't and very much doubt it'll do anything, other than maybe take off a finger or two. If the drill has a universal motor it might have enough residual magnetism of it's own to generate some voltage but that's not too likely.

If I needed to re-excite a generator, first off it wouldn't be moving. Would probably use a couple of hits off a car battery (depending on winding resistance).

 

[mopowr steve]

Sounds to me there is a problem with the exicting circuit of generator whether it gets it from the battery that starts it or from the magneto under the flywheel. There should be a little voltage coming from somewhere to excite it. Maybe you have a bad capacitor on the field.

 

[mopowr steve]

If not mistaken, the field of a generator just sitting and not running whether be 1 minute or 10 years is not excited. I dont think it usually just sets there with some kinda mystery mojo.
The rotation of say an engine in some fashion when running will provide the electric to be used in exciting the generator field which like I said could be either by magneto, battery, or maybe a magnet within the generator to create the excitement voltage.

 

[iwire]

If not mistaken, the field of a generator just sitting and not running whether be 1 minute or 10 years is not excited.

But it can lose its residual magnetism which requires restoring it.

Self excitation

Modern generators with field coils are self-excited, where some of the power output from the rotor is used to power the field coils. The rotor iron retains a magnetism when the generator is turned off. The generator is started with no load connected; the initial weak field creates a weak voltage in the stator coils, which in turn increases the field current, until the machine "builds up" to full voltage.

If the machine does not have enough residual magnetism to build up to full voltage, usually a provision is made to inject current into the rotor from another source. This may be a battery, a house unit providing direct current, or rectified current from a source of alternating current power. Since this initial current is required for a very short time, it is called "field flashing". Even small portable generator sets may occasionally need field flashing to restart.

https://en.wikipedia.org/wiki/Excitation_(magnetic)

 

[cpinetree]

More on field flashing: http://www.endtimesreport.com/dead_gen.html

With a suicide cord and 3 lamps :? and also the drill method.