Repower with ????????????????????????

[IDUNA]

Our engine is fitted with a 35 amp alternator. House bank capacity is 450 amp. Regulator is a Balmar ARS-5 multi-stage unit. Based on current thinking or market trends, an alternator of 1/4 the house bank is recommended or 100 amps.

When we charge our batteries with the alternator, the bulk phase charging time is less than a minute before the regulator switches to the acceptance phase - 25-28 amps starting. Based on the house bank capacity and the max output on the regulator, I would expect the bulk phase period would be longer and the alternator amp output to be greater than 30 amps. This is not the case. Granted amp output of an alternator decreases as temperture increases.

I am curious, if anyone else has ever observed amp output during the charging phase and the length of time of the bulk phase before the acceptance phase occurs.

Our last boat had a “smart regulator” and high amp alternator. The bulk phase was relatively short before the acceptance phase.

Rod

[Mark_Giegel]

Hello Bob,

I had called Mack Boring and talked to their parts people. They told me that the standard alternator provided on the 3YM30 was a Hitachi 60 amp unit and the part number was 128271-77200. I was tyring to determine the value of the new one I had which came with the boat.

My boat has a Seafrost coldplate system which had both the engine driven compressor as well as the 12 volt system…both sharing the common coldplate but having a separate loop for the coolant for each system. My engine driven unit was the original system from first owner and was swithched to the Yanmar when installedwhen re-powered from the Volvo. The 12 volt takes much longer to get the plate dowm to temp compared to the engine driven unit. The engine driven developed problems that cost too much to repair so I removed the engine compressor, bracket etc and just use the 12 volt system. You have to weigh the merits of each. I think that if you are doing some long cruising the engine system may be better. For me, I like less junk in the engine compartment and do not use it often enough to justify to more expensive engine driven system.
Best
Mark

[John_Cole]

FYI: Attached is an image of a Yanmar 3YM30 fitted into a Cape George Cutter.

[Stewart]

FYI find a couple of photos of 3YM 30 just installed into hull 126, I had a engine pan fitted as supplied by CGMW (most kindly) which comes with ss metal panels in situ to secure the engine to. The pan to my mind is a delight and makes the whole operation much simpler.

[svshaula]

IDUNA Wrote:

Our engine is fitted with a 35 amp alternator.
House bank capacity is 450 amp. Regulator is a
Balmar ARS-5 multi-stage unit. Based on current
thinking or market trends, an alternator of 1/4
the house bank is recommended or 100 amps.

When we charge our batteries with the alternator,
the bulk phase charging time is less than a minute
before the regulator switches to the acceptance
phase - 25-28 amps starting. Based on the house
bank capacity and the max output on the regulator,
I would expect the bulk phase period would be
longer and the alternator amp output to be greater
than 30 amps. This is not the case. Granted amp
output of an alternator decreases as temperture
increases.

I am curious, if anyone else has ever observed amp
output during the charging phase and the length of
time of the bulk phase before the acceptance phase
occurs.

Our last boat had a “smart regulator” and high amp
alternator. The bulk phase was relatively short
before the acceptance phase.

Rod

Rod,
I’ve started a new thread as this isn’t really about repowering. I’ve spent lots of time, plotting alternator amps out and house battery volts, over time. The alternator amps during bulk charging, using a smart charger, can be close to the alternator’s rating,and that can destroy the alternator. The alternators that come standard on engines are not heavy-duty enough to run flat out for very long. The alternator’s rating is probably based on a cold alternator, and output is less when it heats up during bulk charging. When you are getting 28-30A out of a 35A rated alternator it is probably putting out its max at that temp. I know of several cases where smart regulator-driven (non-high output) alternators have been burned up, with solder running out the bottom! High output alternators are much more sturdy–bigger bearings, diodes, KKK rating, better belts, etc. (see the Primer at amplepower.com).

A short bulk phase could be due to sulphated batteries, or if your battery bank is not deeply discharged.

On Shaula’s 3GM30F, I have an Ample Power smart regulator (SARv3) and their 105A alternator, and have adjusted to SAR down to a maximum output of about 50A. Our house bank is 200Ahrs, and I’m probably being overly protective, but this was easier on the engine, alternator and the batteries.

Hope this helps.

Dan

[svshaula]

Rod, and others,
I was trying to start a new thread but goofed. Please respond to ‘alternators’ and charging batteries on the new thread I finally got started. Thanks.
Dan