32E 2 brush conversion - technical info needed

[RvP]

This question has to do with converting a 32E 3 brush to 2 brush operation.

I know the 32E 3 brush wasn’t meant for all night riding with the lights on and I know that the efficiency of the 3 brush generator falls off quite rapidly above 30mph. I have read information on forums, in catalogs and Harley shop notes about converting the 32E to 2 brush to get around the inefficiencies of the 3 brush. I am also aware that for the job the 32E 3 brush and the 6V 2 brush generators were designed for they were adequate with the 6V 2 brush giving consistent voltage at high speeds and maintaining the charge on the battery better than a 3 brush.

I am posting this not to start a debate on the values and virtues of converting the 32E to a 2 brush but just looking to fill in some missing technical information on the conversion to 2 brush. Here are my questions:

1) Cycle Electric makes a 6V solid state voltage regulator model #CE-101. This voltage regulator has a circuit to limit the generator output to 15 amps, same function as in a 3 unit mechanical voltage regulator. I called Cycle Electric and spoke to a technical person, Carl, to find out if the 15 amp current limit was too high for a 32E converted to 2 brush operation. Carl felt the 32E is safe up to 15 amps and therefore the 15 amp limit is adequate. For all my years fooling around with a 32E (4 years total) I have always felt and read that it is only good for 10 amps. Past that the armature will get hot and burn up, throw solder, etc. Does anyone has any idea what the danger point of the 32E current output when hot, i.e. is Carl right?

2) In the Harley shop notes about converting the 32E to 2 brush I have never seen a recommendation about what voltage regulator to use, not even 2 unit versus 3 unit. If Harley used a 3 unit voltage regulator and gave the part number some insight into what Harley felt the maximum safe current limit is based on the 3 unit voltage regulator specs. If a 2 unit regulator was used nothing can be determined since the 2 unit voltage regulators do not have current limiting 3rd unit.

3) On one of the wiring diagrams showing the 32E converted to 2 brush operation it shows how to connect the generator to a voltage regulator. There is also shown a fuse in the field circuit between the generator and the voltage regulator. The value for this fuse in not shown on the diagrams I have seen. Does anyone know the value of this fuse when a 32E is converted to 2 brush?

4) From the above, is the purpose of the fuse to protect the generator from putting out excessive current by the field fuse opening if the field current got above the fuse rating? If I am correct about the field fuse that would imply the 32E 2 brush conversion used a 2 unit voltage regulator since the 2 unit does not have the 3rd unit that limits the generator output current.

That’s all the questions I have for now. Thanks in advance.

[bmh]

Shop Dope #313 has some of the answers you seek. I scanned a copy but couldn't get it to upload, it has a wealth of regulator info. in regards to 2 brush conversions it states that delco-remy #283 or #307 were original equipment for that application, but advises when replacement is required that delco # 1118388 (H-D # 74511-51) be used.
Settings for #1118388 :
cut out relay closing voltage------6.6 volts
voltage regulator setting----------7.5 volts
current regulator setting----------18 amps
can try to upload again tommorrow or I could send you a hard copy if you like.

[Rooster]

Brian, is it too much to ask for a copy of that shop dope for myself? That's great information!

[RvP]

Amazing!

Brian,
Thanks for the information, it is really eye opening and confirms Carl’s (from Cycle Electric) assessment about using the CS-101 with the 15 amp current limit. 15 amps is within the ball park and it gives me confidence in the Cycle Electric products and knowledge. It is also amazing that the voltage regulator spec’d in the shop dope has the current limit at 18 amps to protect the armature. I don’t know how long the 32E armature can sustain 18 amps but it implies to me that if I am pulling less than 18 amps, for example 14 amps out of the 32E continuously, the 18 amp current limit would not kick in when using the delco # 1118388 (H-D # 74511-51) or the 15 amp current limit with the CS-101.

If you cannot upload the shop dope then I would appreciate you sending me a hard copy. If you can Email it, my Email address is RVPapasso@prodigy.net. If you need my postal mail address let me know and I will send that to you.

The only question left for me is what the fuse rating is and what is it’s purpose. Thanks again!

Ronald Papasso AMCA #3129
Seaboard Chapter Editor for 19+ years!

[bmh]

OK got it uploaded and will post. But upon reading it again tonight I have some questions. The diagram you refer to for conversion wouldn't be # 121G would it? That applies to Radio generators, as apparently the reference in #313. Radio generators are a whole different animal. Even the non fan cooled variety I believe. If you need more juice and your not that concerned about being correct why not run a model 58? Personally for me, anything I intend to run at night on a regular basis would be 12 volt.

[RvP]

32E Wiring Diagram

The following diagrams to convert the 32E and 52 from 3 brush to 2 brush are from a parts catalog. I have seen a similar diagram in a panhead manual and this is also referenced in Palmers book. None of the diagrams or references state what voltage regulator to use or what size fuse.

[Perry Ruiter]

Note that the 74511-51 regulator that is set at 18amps applies to a fan cooled generator (and indeed the two brush conversion referred to in Shop Dope 313 is of a fan cooled 3 brush generator not a 32E). Whether or not fan cooled, the police generators are substantially larger than a 32E (longer armature and larger fields coils are what give them greater output).

Attached is a scan of Service Bulletin 418 which discusses conversion of both 32E and model 52 generators to 2 brush. The regulator called out there is 74511-41 (which is number 8375-41 in the above scanned Shop Dope 313). From Shop Dope 313 we see this is rated at 13amps and that is when used with non-fan cooled police generator not a 32E (eg: a generator with more jam than the 32E).

I've said it before, you can get more than 10 amps out of a 32E, but that's a safe rule of thumb. I freely admit I have no formal training in electrical engineering so factor that into your decision on whether you think I know what I'm talking about or not, just don't come crying to me when your armature flings its solder ... Perry

[Rooster]

Thanks you guys, valuable stuff.

[Chris Haynes]

Rooster,
Are you standing there telling me that you haven't bought the Shop Dope's?

[Rooster]

Rooster,
Are you standing there telling me that you haven't bought the Shop Dope's?

No, I'm sitting down.

[Paps]

The shop dopes are great except for finding what you are looking for in them. It is usually in them but it takes one page at a time to locate it.

[RvP]

Even Better

Thanks to everyone (again) that supplied the missing information and advice!

[bmh]

Paps, maybe thats why they call it dope.

[knuckleheadtim]

I think you are confusing the 32E genertor with the 32E2 generator. The 32E2 was a 3 brush radio generator with a longer armature and field coils , but no fan, just like a 32E2R but with a 3rd brush. It was only used in '38, and maybe earlier, and was quickly replaced with the 2 brush 32E2R. The 3rd brush was supposed to limit current output, but was totally unnecessary with a 3 pole regulator. The conversion information in the manuals is written for radio generators, not the 32E standard genertor. The fanless generators were limited to 13 amps and the fan models to 18 amps.

If you rewire a 32E generator for a regulator, you shouldn't have a problem with maximum output damaging the generator as the demand will be unlikely to reach peak for any length of time. The exception is if you get a short in the system or have a lot of accessories, in which case a current regulator does an excellent job protecting the generator.