generator question

[l jackson]

Hi, I need help to know which poles are the "F" and "A" poles on this generator? Trying to determine why it's not charging. Thanks

 

[Ken Hansen]

Pretty sure the "A" terminal is the larger of the two and the field is the smaller one. Or to say it another way the one towards the out side is the "A"

 

[Ken Hansen]

(quoted from post at 11:27:32 06/26/20)
Pretty sure the "A" terminal is the larger of the two and the field is the smaller one. Or to say it another way the one towards the out side is the "A"

May even be marked on the generator frame under that band.

 

[rustred]

armature is larger and most time the A is stamped in the housing by the terminal.

 

[John T]

Here are a few methods to determine which is ARM and which is FLD on a Genny, hopefully others can add more methods I missed .....

1) If you look closely under dirt or paint or grease you might see A or F stamped ???
2) Often the ARM post is bigger then the F post.
3) If you unhook everything and had a good accurate at low scale ohm meter. With respect to ground, F would be a few ohms higher then A
4) A on genny is the one connected to the Voltage Regulators GEN/ARM terminal, F on genny is the one connected to the FLD post on VR
5) On some 4 terminal VR's with BAT FLD LOAD all side by side together, the ARM is all by itself underneath or on one corner

Now once you have all that figured out and want to find the cause of non charging, work through my Troubleshooting Procedure linked below

https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=2060825

John T
John Ts Charging Troubleshooting

 

[wore out]

The larger of the two is "A", the smaller is "F". (IF they are original and someone hasn't replaced one or both.)

If you look CLOSELY there will be an "A" or an "F" stamped in the steel housing near each post. I've never seen one that wasn't stamped, if you look closely.

<img src = "https://i.imgur.com/qhgur5E.jpg">

Like in this photo, the guy highlighted them in white. You can see where the "A" should be stamped on yours.

<img src = "https://i.imgur.com/LL184VE.jpg">

As to your other question, the regulator is rubber mounted and there's a length of small braided copper wire that connects regulator body to the mounting base IF it hasn't vibrated off or been otherwise removed over the years.

The FIRST thing to do after confirming the ground lead is intact is to polarize the generator by momentarily jumpering between the "B"/"battery"/"hot" terminal on the voltage regulator and the "A" "Armature" terminal on the V.R..