Smart Regulator for Yanmar Alternator

[Celestialsailor]

I Have a Yanmar 4JH 40+hp. engine with the stock Alternator. Does anyone know if I can wire it to a multi-stage (smart) regulator? If so is there a piticular brand and model you might suggest?

[Rick]

The Hitachi alternators on the Yanmar engines are good ones when converted to be controlled by an external regulator. If you can get the 80A unit which will put out over 90A with an external regulator.

If you can still find them the Incharge (or Alpha) regulators sold by WestMarine are the easiest to install and use. If you use a Balmar regulator the best one (in my opinion) is naturally the most expensive. All of the Balmar regulators are a pain in the ass to set up from any default setting.

Here are some instructions that you might find useful if you choose to convert your alternator yourself:


SUBJECT: Converting an internally regulated, or "N" field alternator to "P" field external regulation.
These instructions are for converting internally regulated or "N" field alternators into the "P" field externally regulated type allowing them to be regulated by external regulators. Please note that modification must also include removing the diode trio in addition to the modifications listed below. As a result, it is recommended that alternator modifications be performed by a qualified alternator mechanic, with you the customer specifically pointing out the need to disconnect the diode trio from the stator windings. If the diode trio is not disconnected from the stator windings extremely high DC voltages can occur which can damage other electrical equipment. Once disconnected you may choose to leave the trio physically in place.
1. Make a reference mark on the case front and back halves. This is to ensure that the alternator is reassembled with the case halves oriented the way they were before disassembly.
2. Remove the four long bolts that hold the cases halves together. Gently tap and pry the front and back case halves apart. The pulley, shaft and rotor will come away as a unit with the front housing. The laminated steel core and stator windings stay with the back case half.
3. At this point, the spring-loaded brushes should have popped out of the brush holder.
4. Note that there is a hole in the back of the rear housing situated so that you can insert a toothpick or piece of wire to hold the brushes compressed in the holder during re-assembly. Use this process later during re-assembly.
5. The goal of this next operation is to end up with one brush directly connected to ground and the other brush connected only to a wire which will be routed outside of the alternator case.
A. First the negative brush: With an ohmmeter or continuity tester, check to see if one brush is already in direct connection with ground. On most alternators, the case is the ground. Others will have a ground stud isolated from the case. In both situations the resistance between the brush and ground should be very near zero. If neither brush is grounded, select one of the brushes and solder a jumper wire onto the brush lead and connect the jumper to ground.
B. The other brush must be disconnected from whatever it is presently connected to, and soldered to a length of wire. This wire should be labeled "Field" or "F", and routed outside of the alternator case.
Pay special attention to maintaining insulation and clearance from wires rubbing on moving parts. Use a tie-wrap to secure the "F" wire where it exits the alternator case.
6. This is a good time to buff the tarnish off the slip rings where the brushes ride.
7. Re-assemble the brushes in the holder, spring first, brush on top, ensuring the brushes can slide freely in their slots.
8. Now use the toothpick or piece of wire (unbent paper clip) to hold the rear most brush while loading the other brush and spring. Advance the toothpick or wire to hold down the last brush and spring.
9. Re-assemble the case front and back halves ensuring the reference marks made in step 1 are aligned.
10. Insert and firmly fasten the four long case bolts tightening them evenly.
10A. Rotate the shaft and note that the pulley runs true and that there is no scraping noise from inside the alternator. If there is, discover the source before continuing...may have to take apart and check the alignment while reassembling.
11. Pull out the toothpick. You will hear a click-click as the two brushes snap down on the slip rings.

11A. Rotate the shaft and note that there may be some slight noise from the brushes against the slip rings...this is normal as long as it is relatively slight.

[Celestialsailor]

Wow Rick...Thanks for the reply. I did not think I was going to hear anything. My Alt. is 60 amp. My new batt. bank will be just over 300 amps. I know the alt. may be a little small but I also have 150 watts of panels and an new AirX (land with enamel paint). I will see how it does the first year in Mananaland. If I need to upgrade, I will. My energy consumption is relatively modest. Your suggestion sounds relitively simple. I researched Incharge (or Alpha) regulators and so far found nothing. I had also heard that Balmar regs. were a challenge to dial in but good factory support. I'll pass on Balmar anyways due to the fact that I feel they over-price everything

[Celestialsailor]

Also...any input on the xantrex regulator?

[Rick]

Balmar makes the regulator that Xantrex markets (at least the one that physically looks like the lower-end Balmar).

Celestialsailer: Keep your eye out for a larger Hitachi...you might be able to get one from others who have opted to buy other brands already designed to be externally regulated (like 100A ones).

[PBzeer]

I bought the Xantrex branded Balmar regulator at $50 less than the Balmar. Has worked well to this point using a 70 amp Hi-output Balmar alternator on my 13hp 2GM.

[Celestialsailor]

Thanks PBzeer and Rick. Occasionally I see a Yanmar/Hitatshi 80 on e-bay for $50. Maybe I will grab one, convert it, then i will have a back up. Back up is what it is about when cruising...

[hellosailor]

Rick-
Bless you! I have a spare Denso alternator that I also want to convert to external regulator. I'm a bit confused by your warning to disconnect the diode trio (they call this one a "diode frame" since there are more than three in it) from the stator. Doesn't that connection have to exist to get things working?? Or be jumped to something else??

I'd also seen a reference to taking that one external wire (from the brush that used to go to the internal regulator) and pulling it out--but then also adding a switch and running it back in to the internal regulator. So, "switch off" breaks the internal circuit and uses the external regulator. "Switch on" restores the internal regulator for emergency use, if the external has gone haywire. Any thoughts on that?

And some clarification on disconnecting the stator/diode frame??

[sailvayu]

Good info about making the change someting I might want to try, but was wondering about what effect if any this would have on the AC tap for the tach
Thanks
sailvayu

[never monday]

Originally Posted by sailvayu

Good info about making the change someting I might want to try, but was wondering about what effect if any this would have on the AC tap for the tach
Thanks
sailvayu

Most external regulators have a terminal to run a tach built in.

[Rick]

Any external 3-step regulator will not allow the alternator to seamlessly drive a tach without problems when transiting to float and sometimes when in float.

One solution in design would require that the regulator monitor the tach output from the alternator as feedback to control some minimum drive while slowly transiting to a lower float voltage (less voltage means less alternator excitation and hence less tach drive voltage). Even then there will be some problems with some tachs which may require higher drive voltage. Regardless, no product exists that does this in a seamless manner for all tachs.

[Roy M]

I went the Balmar route with my Yanmar 3GM30F and have been very happy. Anyone want to make an offer on an unused Hitachi 50 amp alternator?

[GordMay]

Yanmar’s tachometers operate from the flywheel sensor on GM series engines, and from alternator pulse on other models.

[Pete the Cat]

I have a Yanmar 80 amp alternator on my Yanmar 3JH4E that has been modified to accomodate external regulation. I know where to hook my smart alternator regulator to control the field (the guy wired the vertical blade in the plug for the field), but have a question about which wires in the harness do what. I have a Pulse wire coming off the Alternator, but I am not sure which wire in the engine harness is the tach wire (choice is red/black or blue/black)--the schematic is confusing. Also, I will have one of those wires left over when I am done--what do I do with that? The regulator I am using is an old Ample Power Smart regulator that was fantastic for fast charging with my old system. I have carried an ARS-4 Balmar regulator for the last couple years as a back up, but am reluctant to part with success.

[GeoPowers]

GREAT info, many thanks Rick!!!