JohnT, help, polarizing generators debate

I've always followed the JohnT instructions for polarizing generators. Flashing BAT power to ARM post.

I posted this somewhere and started a mini argument, from a guy who always flashed BAT to FIELD. He stated source as the JD electrical manual.

Others have been on one side or the other.

I did more digging, and apparently it depends if you have an A circuit or B circuit generator on how it's flashed.

But I'm wondering if it's even a hard and fast rule....because we both made either choice work on JD generators? I can't remember if JD used A or B type circuits.

Some more info stolen from the internet.....

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Depends on the circuit in your generator. According to the Delco-Remy service bulletin dated 7-3-61, there are two different circuit types of generators:

Type A circuit - The field winding is connected to the insulated brush inside the generator and is connected to ground through the contact points in the regulator.

Type B circuit - The field winding is grounded inside the generator and is conncted to the armature circut inside the regulator.

To polarize the generator with:
Type A circuit - Momentarily connect a jumper lead between the regulator BATTERY and ARMATURE terminals after all leads have been connected, but before the engine is started.

Type B circuit - Disconnect the lead from the regulator FIELD terminal, and momentarily touch the lead to the regulator BATTERY terminal. This should be done after all other leads have been connected and before the engine is started.

Thanks to anybody!
Brandon

Every 6 or 12V Delco I have ever seen was type A. Every 6V Autolite I have ever been around was type B. I have seen a type A Autolite that was 12V. Both control output via the field. The differance being a type A always has full voltage feeding the field and controls output via the ground while a type B field is always grounded and the control is via the input voltage.
Your information is valuable as the number of people who understand these systems shrinks daily and a whole lot of well intended guesses are wrong. Thus we have major sales of one wire alternators. Luckily I was schooled in them and manage to keep all of my stuff original and properly operating.

I must have been lucky because the Case has an Autolite, and the Deeres are Delcos, and I've treated them the same.

Thank you for identifying A vs B!

How do you tell if you have A type or B type??

You know, I have to wonder it even matters because the way a generator works. There are no permanent magnets in a generator. If you charge the field, you charge the armature too, and vice versa.

That's what I'm thinking

No matter how good a generator works its still far inferior to an alternator and most generator system parts now a days is junk anyway so for around $80 I can replace the whole generator mess with a much better alternator.

If you had it off and sent to a rebuilder, they bench test run them and I never needed to polarize them. I always feared telling anybody to touch live wires around as they can easily fry something !

I've worked on 6v Autolites and Delcos and the Autolites were A circuits, contrary to what Butch said.

Good morning Brandon, long time no see since I gave my Electrical Seminars at Two Cylinder Expo in New York. I will address your good questions and comments one at a time:..
..

1) I've always followed the JohnT instructions for polarizing generators. Flashing BAT power to ARM post... .


I STAND BY THAT INSTRUCTION when it comes to my Deere posts and many other tractor brands that use CLASS A CHARGING SYSTEMS. NOTE I often added that if the ARM terminal on a VR is hard to get to just jump BAT on the VR direct to the gennys ARM post, does same thing... ..


2) I posted this somewhere and started a mini argument, from a guy who always flashed BAT to FIELD.

THAT IS WHAT I ADVISE FOR CLASS B CHARGING SYSTEMS

3) Others have been on one side or the other.

TRUE because A or B are different

4) I did more digging, and apparently it depends if you have an A circuit or B circuit generator on how it's flashed... ..


YOURE EXACTLY CORRECT

5) But I'm wondering if it's even a hard and fast rule....because we both made either choice work on JD generators? I can't remember if JD used A or B type circuits... .


ALL THE TWO CYLINDER DEERES USED CLASS A AS FAR AS I KNOW.. .



6) Depends on the circuit in your generator. According to the Delco-Remy service bulletin dated 7-3-61, there are two different circuit types of generators:..


Type A circuit - The field winding is connected to the insulated brush inside the generator and is connected to ground through the contact points in the regulator.

Type B circuit - The field winding is grounded inside the generator and is conncted to the armature circut inside the regulator.

I dont have diagrams of all VR's BUT THOUGHT THE GENNYS FLD POST CONNECTED TO FLD TERMINAL ON THE VR ON CLASS B SYSTEMS ???????????????????????????????????????

7) To polarize the generator with:
Type A circuit - Momentarily connect a jumper lead between the regulator BATTERY and ARMATURE terminals after all leads have been connected, but before the engine is started. .. SAME THING IVE ALWAYS SAID....



8) Type B circuit - Disconnect the lead from the regulator FIELD terminal, and momentarily touch the lead to the regulator BATTERY terminal. This should be done after all other leads have been connected and before the engine is started...

I AGREE

NOTICE AND FYI of how Polarization works for anyone who may not understand:::::

When you pass current through the gennys field windings in a certain direction, you impart a degree of magnetism in the soft iron field poles AND THE DIRECTION OF CURRENT DETERMINES THE NORTH SOUTH MAGNETIC FIELD POLARITY. Thats what polarization is all about

FINAL some jump BAT to ARM on EITHER A or B systems which can work HOWEVER I advise and prefer the same as recommended above

BOTTOM LINE do as you please its YOUR tractor YOUR risk,,, but I stand by what I always posted and the manuals above ON A SYSTEMS JUMP BAT TO ARM........ON B SYSTEMS JUMP BAT TO GENNYS FIELD POST even if other methods may still work.

REGARDLESS passing current through the field windings in one direction or the other is what sets the North South magnetic field polarity

Hope this helps Brandon if I missed anything maybe he other fine electrical minded gents can add to or correct this ??????? AGAIN even if other methods might work I STAND BY THE MANUAL and its whats ALWAYS worked for me

John T Live in the RV from the Elnora Indiana tractor show

Brandon FYI here's how things work: You polarize the North South Magnetic Field Polarity in the soft iron field poles by passing current in a certain correct direction in the field windings. The FIELD POLES are whats polarized with a North South magnetic field polarity not the armature windings.......Then when the armature a bunch of wire coils are rotated in the field poles magnetic field the Electric + - polarity is determined based on how the field poles were polarized...

Field is polarized NOTTTTTTTTT the armature.

John T

(quoted from post at 06:03:26 09/08/23) I've always followed the JohnT instructions for polarizing generators. Flashing BAT power to ARM post.

I posted this somewhere and started a mini argument, from a guy who always flashed BAT to FIELD. He stated source as the JD electrical manual.

Others have been on one side or the other.

I did more digging, and apparently it depends if you have an A circuit or B circuit generator on how it's flashed.

But I'm wondering if it's even a hard and fast rule....because we both made either choice work on JD generators? I can't remember if JD used A or B type circuits.

Some more info stolen from the internet.....

---------------

Depends on the circuit in your generator. According to the Delco-Remy service bulletin dated 7-3-61, there are two different circuit types of generators:

Type A circuit - The field winding is connected to the insulated brush inside the generator and is connected to ground through the contact points in the regulator.

Type B circuit - The field winding is grounded inside the generator and is conncted to the armature circut inside the regulator.

To polarize the generator with:
Type A circuit - Momentarily connect a jumper lead between the regulator BATTERY and ARMATURE terminals after all leads have been connected, but before the engine is started.

Type B circuit - Disconnect the lead from the regulator FIELD terminal, and momentarily touch the lead to the regulator BATTERY terminal. This should be done after all other leads have been connected and before the engine is started.

Thanks to anybody!
Brandon

Click to expand...

person who really understands the A/B circuits, me, can tell you that flashing either by momentarily connecting BATT to Arm polarizes either just the same, buy momentarily running current through the field coils. I have no earthly idea why a different method has long been recommended for the B-circuit, other than possibly the B_A_F terminal arrangement on the A-circuit and the A_F_B arrangement on the B_circuit might lead to someone jumpering the two left most terminals on both. That is fine for A_circuit, but on B_circuit, disastrous, because such would not only run the typical ~4 amperes thru the field coils (just as in the A_circuit), but an additional ~60 amperes through the armature via the Field contacts in the regulator. Those contacts are designed to switch ~4 amperes!

Addendum to my post:
Summary: You will notice that if you jumper BATT to Field on A_circuit, that you are trying to place a short circiut across the battery via Field contacts and should immediately ruin field contacts and in a few seconds burn wires!

Do Batt to Field on B_circuit and you will be running armature current through the Field contacts, rated for ~ 4 amperes and now being asked to carry ~ 6v/0.1 Ohm = 60 amperes. Again disaster.

Do Batt to ARM on EITHER and ALL IS WELL & POLARIZED!

Thank you JohnT for weighing in on this. I obviously know just enough to get myself in trouble. I could never keep it straight which parts were magnetized, makes sense that it'd be the field poles.

To be honest the A vs B is still confusing haha , but I work on mostly Deeres, I believe the Fords were equipped with B types.

I'll just keep following your simple and good instructions, and keep recommending or repeating them.....they WORK

Brandon

(quoted from post at 10:13:43 09/08/23) Thank you JohnT for weighing in on this. I obviously know just enough to get myself in trouble. I could never keep it straight which parts were magnetized, makes sense that it'd be the field poles.

To be honest the A vs B is still confusing haha , but I work on mostly Deeres, I believe the Fords were equipped with B types.

I'll just keep following your simple and good instructions, and keep recommending or repeating them.....they WORK

Brandon

Click to expand...

ord has used both A and B, depending on the year

Thanks Brandon, maybe we will meet up again.

On an A system one side of the first field connects to the ARM post (2 brush gennys), the two splice in the middle, the end of second field wires to FLD post and how much how long and what effective resistance TO GROUND (VR's job) is what regulates charge since it regulates field current.......

On a B system one end of the second field is grounded, the first wires to FLD post and the VOLTAGE (not degree of ground) is whats regulated via the VR

The greater the field current the greater power the armature produces therefore regulating field current is how a VR works

John T

The armature has laminations, each pole field is one solid chunk if iron. The laminations are insulated from each other with varnish that keeps them from developing an internal permanent magnetic field by creating eddy currents that neutralize each other and prevent them being magnetized themselves but allows them to transfer magnetism to the windings. Jim

Sorry but I can't get into this discussion. Making my way through the little booklet found in the link below ... which I should add is a lot more simple than polarizing a generator ....
Untitled URL Link

Without flame! The B circuit genny has internally grounded field and externally Hot connection to the non ground side of the battery when the generator is operating. This voltage comes from the VR through the regulator contacts, which vibrate to interrupt the flow, controlling the field magnetic field intensity. When not operating those points are open, disconnecting the excite current. I believe that touching battery (non-ground) voltage to the F terminal of a B generator will just send voltage through the field windings to ground, and not affect the open regulator contacts. Jim

(quoted from post at 11:39:53 09/08/23) Without flame! The B circuit genny has internally grounded field and externally Hot connection to the non ground side of the battery when the generator is operating. This voltage comes from the VR through the regulator contacts, which vibrate to interrupt the flow, controlling the field magnetic field intensity. When not operating those points are open, disconnecting the excite current. I believe that touching battery (non-ground) voltage to the F terminal of a B generator will just send voltage through the field windings to ground, and not affect the open regulator contacts. Jim

Click to expand...

orry, but Field control contacts are closed when at rest. Arm contacts are OPEN
at rest.

This post was edited by JMOR on 09/08/2023 at 09:19 am.