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Old 13-09-2015, 17:05   #1
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3JH5E second alternator?

Does anyone have a 3JH5E with a second alternator? There seems to be a genuine yanmar second alternator kit for it.

I seem to have read somewhere that this motor cannot have high output alternators due to the increased side loading.

What is the biggest alternator(S) that can safely be put on one of these motors?

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Old 13-09-2015, 18:20   #2

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Re: 3JH5E second alternator?

The only load you could not put on the engine would be a thrust load, this ain't that, and I doubt another alternator would strip the damper key. I would go with Yanmar parts so alignment is more likely.

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Old 14-09-2015, 18:17   #3
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Re: 3JH5E second alternator?

Checkout the Electromaxx high output alternators. They also sell a kit to add new pulleys to the engine to allow use of a 1" flat belt. I put a 140 Amp on my 3GM30F and very pleased with the results.
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Old 15-09-2015, 00:49   #4
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Re: 3JH5E second alternator?

Thanks Bob and guy.

Yes the electromax one looks good. I like the flat belt type for high power delivery. I was thinking of a second 180 amp on each engine supplying a LFP bank with a switch to disable second alternators via balmer controller if more engine power was required for any reason.

I agree that it might be better with a yanmar setup for alignment issues but I do like the flat belt over a traditional v belt.

The yammer setup seems to go up to 80 amp primary + 160 amp secondary. That might be due to the v belt power limitation. The electromax can do twin 180 amps, perhaps more..?
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