repolorize generator on a WD

What Polarization does is to impart residual magnetism into the iron field poles having the correct North/South magnetic polarity so that when the armature (a coil of wire) begins rotating inside that magnetic field, it starts to charge in the correct electrical +/- polarity. Thats done by passing current through the Field windings which imparts the correct North/South magnetic polarity in the poles.

In Class A Delco type charging systems, polarizations accomplished by a couple ways. To make sure the Field has a good ground, you could temporarily dead ground it to the gennys case and then: NOTE this assumes and requires the BAT terminal on a Voltage Regulator or a Cutout Relay is hot (as it must be) and the Genny is grounded (as it must be) and all else is wired correct n works.

TO POLARIZE A GENNY

1) Temporarily Flash jump/flash a wire from the Voltage Regulators BAT terminal over to its GEN (or ARM) terminal and you ought to get a small spark. This assumes the VR's BAT terminal has a hot battery feed as it should and if alls wired right and the ammeter is good and continuous.

2) Same things accomplished if you jump/flash any hot battery feed (such as BAT on the VR or elsewhere) direct to the Gennys ARM post.

3) If it only has a 2 wire cutout relay as opposed to a 3 or 4 wire VR, simply flash/jump its input (BAT) and output (GEN) terminals together to get the spark or from the BAT terminal down direct to the Gennys ARM post.

If its a Class B system like some Fords used with the Field winding internally grounded (A VR on those regulates the Field input current as opposed to the ground on Class A), you simply flash the Field. Theres a great explanation by Sound Guy a lil down below on which Fords used those systems, Im not much into Fords, sorry.

Best wishes n God Bless

John T

There are 2 reasons to polarize a DC generator on an antique piece of equipment....

#1. It has sat a long time, so the field polepieces in the generator have lost their residual magnetism, and it will not charge, or the generator has just been repaired or replaced.

OR:

#2. Some idiot has installed the battery with the polarity incorrect, and you are correcting the battery ground polarity, and need to polarize the charging system to match the battery polarity.

If the charging system has been working, and the battery is removed an replaced (and is connected with the proper polarity), NO polarizing is needed.

If a 1 wire 3 brush genny / cutout.. just jumper the cutout connections.

If a 2 brush genny.. determine if it is A or B circuit.

A circuit polarizes by jumpering arm/bat full fields by jumpering fld/grnd

B circuit polarizes by jumpering bat/fld also full fields by jumpering bat/fld...

Remember that you polarize the unit with it not running.. and full field it with it running.

Motoring tests help.. most gennies that will motor.. will charge.

To find out if you are A-circuit or B circuit.. you could open the genny and see where the field is connected... A circuit has field connected to armature... B circuit has field connected to ground.. If you don't want to open it.. and have a correct vr.. flip it over and look at the wire wound bias resistor... On a circuit.. bias resistor is between fld tab and ground tab. On b circuit bias resistor is between arm and fld tab.. thought there may be another resistor possible to ground tab as well.

Soundguy