Removing internal regulator

Looking to go to external regulators on both engine alternators. Has anyone removed the internal regulator themselves or is that best done by an alternator shop?

Bob

I think that it is best done by an automotive electrics shop. But beware:

OEM alternators are not designed to have an external regulator amping up their output for hours and hours on end. The windings, cooling system and diodes are not up to the task.

Some alternators might be ok, particularly some Leece Neville models. But not the Hitachi OEM alternator in Yanmars.

You will probably get more amps out of your alternator by making this change, but maybe not for long.

A high output alternator such as supplied by Balmar, Hamilton Ferris, Powerline, etc is more expensive for a reason.

David

Not really trying for more amps. It being a power boat there are lots of engine hours so more output isn't really necessary. One of the alternators has been flaky for some time so it needs to be looked at anyway. With both alternators going one or the other tach usually quits at some point in time and I also would like a modern three stage regulator.


Bob

Ok, I kind of understand, although your batteries act as a buffer and any flakiness in alternator output should be dampened by them. But watch your panel voltmeter. If it stays above about 13V with the engines running, then your charging system is ok.

Your tachometers dropping out is another issue. I presume your tachs take their input from the un rectified stator output of the alternator. Most use a flywheel pickup and have nothing to do with the alternator.

In any case buy Balmar regulators or someone else's that has the capability to set the maximum alternator output at a pct of maximum. In your case I would set it at 50% so as to not overload the alternator. That will still give you more long term charging capability than the OEM internal regulator.

Balmar also makes a Duo Charge external regulator that can power two alternators in twin installations. But you loose redundancy.

David

The tachs come off the alternators and both alternators charge the start battery with an ACR to also charge the house bank. I went through all this when we first bought the boat. The ideal solution would be two Balmar regulators and their Centerfielder between them. Almost $1000. So I'm going to try one regulator feeding both alternators through oil pressure switches, that way if one engine is off, the field won't see any current. If that presents problems I'll have to go with the second regulator and the Centerfielder.


I was hoping there was an easy way to remove the internal regulator, but I guess I'll go to the alternator shop.


Bob

Bob: We had a factory Delco changed from internal to externally regulated. The shop did this plus the bearings, brushes and tested for about $50. We used this as a spare since you couldn't run the Perkins without an alternator (part of the belt/tensioning system). We only ran it once for about 50 hours with no issues when the primary, high output alternator, went out till it was repaired. It was a cheap spare/back up but only put out ~45 amps vs the 125 amps from the Balmar.

I would go to the alt shop , and have the alts marked for the direction of rotation.

The tech can check that it has a proper directional fan installed , instead of a universal.

An old alt may not be worth the effort as its hot rating may be pityfull.

I would look at truck alts , about 135A ,$135.00 made for long term use at heavy loads , and the external V reg wiring is standard.

Just to close this out, I went to my favorite alternator shop. It took the guy less than a minute to remove the internal regulator, which is actually mounted on the outside, and show me the connections for the external regulator. These are Motorola alternators, built in France, so this may not apply to others. The regulator is held on with two screws and connects to the alternator with five spade connectors, two of which are the two connections to the brushes.


After he did the first one, I'll do the other one myself. Piece of cake, for once.


Bob

BobH said:

...After he did the first one, I'll do the other one myself. Piece of cake, for once. Bob

Click to expand...

Bob: He probably did or you know how to but I have to ask, did the alternator guy show you how use a couple of paper clips or tooth picks to hold the brushes back for reassembly?

There was no disassembly of the alternator required. The "internal" regulator mounts on the outside of the alternator, held on by two screws and five spade terminals.


Bob

Did it look like this? I just bought one from these folks and there were very helpful.

DB Electrical - NEW ALTERNATOR CATERPILLAR ENGINES 3196 3208 3406 3408 3412 3176 3176B

Not at all. Mine came on a Taiwanese boat built in 1986, I'm surprised they even used semiconductors.

Bob

Do you think you could post a couple of pictures and a short tutorial?

I'll give it a shot, probably this afternoon.


Bob

When I bought my engine, it came with a Balmar 100A, but no regulator. It must have stayed with the boat. Did a little snooping and it turns out the Balmar is really just a Ford/Autolite. I went to the alt shop and bought an adjustable Autolite regulator for around 40bucks. Hooked it up and dialed volts to 13.8. Been flawless for 2000hrs.

To convert an alt to external reg, you need to get to the connections for the two brushes. On some like the motorola mentioned, the reg is mounted to the back so you can do this easily.

On others such as Delco, you have to take it apart and get a little creative on the terminals. Basically the regulator and the exciter diode come out. Then look at the pigtails going to the two brushes. You want to make connections to them and lead them out of the housing. These go to the field connections on the reg.

A good ext reg should have some limit on the field volts/current to avoid burning up the alt in a high load situation. A really good one will have this limit adjustable. You don't want to put in so much field that alt output goes above the point that it breaks thermal limits. i.e., the "smoke limit"!!!

The picture on the top shows the regulator attached with the two screws. The other picture is with the regulator removed, showing the two spade terminals for the field connection. The smaller one on the right needs to be connected to ground and the bigger one on the left to the output of the external regulator.

Bob

I have done so on a couple AC Delcos for worktruck house bank.

Point to keep in mind is that there is a need to use non-conducting washer of some type. IIRC it is in a place that original regulator base is the insulator. Sorry I don't recall anything more specific or helpful. The brushes did not need to be messed with IIRC.