New Alternator Burning

[Stu Jackson]

Just as a side note:  at a 3% voltage drop #2 wire @ 100 amp is only good for a very, very short distance.

In a way, you're right.  However:  http://genuinedealz.com/voltage-drop.html 

20 feet (out & back, remember) of #2 with 70A is 3.75%.  Because of battery acceptance, we never see more than 60A out of our 100A alternator.  And with the Small Engine Mode, it's well less than that.  Add in the regulator's amp management feature and the #2 wiring is more than adequate.

[mainesail]

Just as a side note:  at a 3% voltage drop #2 wire @ 100 amp is only good for a very, very short distance.

In a way, you're right.  However:  http://genuinedealz.com/voltage-drop.html 

20 feet (out & back, remember) of #2 with 70A is 3.75%.  Because of battery acceptance, we never see more than 60A out of our 100A alternator.  And with the Small Engine Mode, it's well less than that.  Add in the regulator's amp management feature and the #2 wiring is more than adequate.

And if you have an external regulator, and sense the battery as you should, then the regulator compensates for the voltage drop once it hits absorption mode....

[efiste]

So, I have had the Blue Circle Alternator rebuilt (again). This time by my more trusted local Auto Electric shop with high output testing equipment. They thought the BC alternator was undersized for 100 AMP. They replaced the Stator wires, added more robust diodes, and swapped the (in their view) worn pulley. They tested it on there load machine, and it easily maintained 100 AMPs out.

I re-installed it last week with a new Balmar alternator temperature sensor. I used my newly purchased belt tension tool to get the belt just right. That tool is a great addition to my bag, btw. It runs hot (as expected), but never gets above the default 107 C temperature threshold at the regulator. Everything seems to be working fine.

In the end, I could have almost paid for a decent Balmar alternator for the cost of the repairs of the BC alternator and my time. Buyer beware. I am not sure I could recommend buying an alternator from Blue Circle for this project. Maybe mine was just the exception, but it seems as if at least 1 or 2 other people have had the same experience. Too bad, because the rest of the project went fairly smoothly using the advice and assistance of the Catalina 34 Association.

Thanks for everyone's help. Now, on to the dedicated starting battery and the 95 W solar panel!!

[efiste]

One other comment... I was not expecting (naively, probably) such an affect on engine performance due to the new alternator. It really affects my motoring speed (1.5-2 kts)! I will probably add the Small Engine Mode switch to be able to cut back the alternator if/when more speed is needed. I do not like motoring. When I have no other choice, though, I might as well get where I am going as fast as I can.

[Stu Jackson]

Really glad to hear you got this sorted out.

Balmar?  Why would anyone spend that kinda $$ for what is essentially a Leece Neville alternator that only costs $200.  You might want to read my earlier post on that on page one of this thread.

Also, please, please, please check your alternator pivot bolt as suggested earlier.

Good luck.  I haven't had that lugging issue with the engine, perhaps because of our use of the small engine mode.  I highly recommend it, as discussed in the link I provided especially when you first start out for a day after a night on the hook; not necessary for a daysail.  That's been our experience with the 100A BC alternator.

I re-installed it last week with a new Balmar alternator temperature sensor. I used my newly purchased belt tension tool to get the belt just right. That tool is a great addition to my bag, btw. It runs hot (as expected), but never gets above the default 107 C temperature threshold at the regulator. Everything seems to be working fine.

The alternator temperature sensor uses the same posts on the regulator as the small engine mode.

The SMALL ENGINE MODE requires a toggle switch between alternator heat sense quick connect spades on the regulator board. Switch in one position lets the full power signal to the alternator. Other position is 50% of required output.

All the toggle switch does is a manual initiation of the alternator heat sensor. You could put them in parallel (i.e., install the toggle AND the sensor) and get the same results (manual AND automatic). I chose manual, but putting the alternator sensor on makes it automatic.

If you start up your engine after a night on the hook, what you will find when you start motoring right away at cruising speed is that the temp sensor will kick in pretty quickly anyway when the alternator gets hot from the initial startup load to fill the house bank (see the "hot alternator" topic).  Then it's simply a management issue:  do you depend on waiting until the alternator gets hot or do you use the s.e.m. manually.  I'd do the latter to avoid overheating the alternator.

Your boat, your choice.  

[Ron Hill]

Not too sure which regulator "efiste" has, but my Balmar ARS 5 has seperate posts for both the alteranator and battery temp sensors. 

Sure wish we could get Spell Check back (that we're probably paying for)!!  A few thoughts

[Stu Jackson]

All the regulators have separate battery and alternator temperature sensors.

Google "iespell" - the spell check on this board is, ahem, clunky.  "iespell" is very simple and works across forums.  I've been using it for years.