Reply
 
Thread Tools Display Modes
 
Old 11-24-2015, 11:41 AM   #21
TF Site Team
 
ksanders's Avatar
 
City: SEWARD ALASKA
Country: USA
Vessel Name: LISAS WAY
Vessel Model: BAYLINER 4788
Join Date: Feb 2011
Posts: 3,954
Quote:
Originally Posted by Bendit View Post
Got a 12hp Kubota (600cc) driving a 24V 120A bus alternator via two belts.
I have fixed the stop control (cable) so that it also acts as a speed control and just set it by ear so there's a reasonable load on the engine. I have an external Ample Power SAR V3 regulator with a current limit pot which I've set to 90A. More current than this and the belts shred noisily and messily.
It has been suggested, on this forum, that I could increase the size of the sheaves on both the alternator and the engine flywheel to prevent this but I can live with it as is. 90A at 28.8 V(charging Voltage) is 2.6Kw which is plenty.
Two inverters supply 230V AC for hairdryers etc...this is probably not a solution if you need aircon, but we run a small fan heater in winter OK.
Sometimes a human ear is better than anything else.

I've been pondering how to govern a engine with a DC alternator and it just has not clicked yet. The problem is that if you increase rpm, you increase output on a alternator up to a point. Lower rpm would be great when you do not need the higher output.

The easiest method would be to govern the engine for the speed at which the alternator reaches it's max output capability. That would provide for good cooling air as well. The problem with that method is that when current needs are lower, for example as your batteries reach different stage set points in the regulator you do not need the engine screaming along at a higher rpm.

This will take some more pondering...
__________________
Advertisement

__________________
Kevin Sanders
Bayliner 4788
Seward, Alaska
www.mvlisasway.com
ksanders is offline   Reply With Quote
Old 11-24-2015, 02:49 PM   #22
Veteran Member
 
City: Victoria, BC
Country: Canada
Join Date: Mar 2010
Posts: 48
I've had this bookmarked for a while. If you scroll down he makes his own Arduino based controller for his DC generator.

mv.VikingStar: Kubota DC Generator
__________________

alesnloggers is offline   Reply With Quote
Old 11-24-2015, 03:33 PM   #23
Guru
 
fryedaze's Avatar
 
City: Solomons Island Md
Country: USA
Vessel Name: Fryedaze
Vessel Model: MC 42 (Overseas Ltd) Monk 42
Join Date: Sep 2011
Posts: 1,052
Quote:
Originally Posted by Ski in NC View Post
Fry- Alts should be able to handle well over 194F, but only alt supplier will know what the actual limit is. Also, you should be able to set current limit, either sensed at stator or exciter, so thermal limit will not be reached.

Is temp limit cutoff adjustable?

I'd find that on/off behavior annoying. Gots to be a better way...
Hi Ski, no the temp set point is not adjustable. They wouldn't tell me what it was (thermocouple, RTD, etc) so I could find something higher. They told me to remove the temp protection.


Yes it is annoying.
__________________
Dave Frye
Fryedaze, MC 42 (Monk 42') 1989 Overseas Co
http://mvfryedaze.blogspot.com/
fryedaze is offline   Reply With Quote
Old 11-24-2015, 03:46 PM   #24
Guru
 
fryedaze's Avatar
 
City: Solomons Island Md
Country: USA
Vessel Name: Fryedaze
Vessel Model: MC 42 (Overseas Ltd) Monk 42
Join Date: Sep 2011
Posts: 1,052
Quote:
Originally Posted by O C Diver View Post
Hmmm, was hoping you were getting a better duty cycle. Maybe you need to move the temp sensor to a different bolt, like the mounting bracket.

Actually moving the sensor to a different bolt my allow a moderately higher alternator temperature without it getting too high. Might be worth trying and verifying results with an infrared temp gun.

Ted
Went through moving the sensor around with minor improvement.They are actually on the mounting bolt. When you consider that the mounts are bolted to an engine block that runs 180 -185F, the 194F set point doesn't stand a chance.
__________________
Dave Frye
Fryedaze, MC 42 (Monk 42') 1989 Overseas Co
http://mvfryedaze.blogspot.com/
fryedaze is offline   Reply With Quote
Old 11-24-2015, 06:01 PM   #25
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 3,886
Quote:
Originally Posted by fryedaze View Post
Hi Ski, no the temp set point is not adjustable. They wouldn't tell me what it was (thermocouple, RTD, etc) so I could find something higher. They told me to remove the temp protection.


Yes it is annoying.

Take the sensor off and go for a run. Monitor stator core temp with an IR gun. I'd say if it got to 250F I'd back off the alt load. Where'd I come up with that 250F number?? Don't ask, but you could probably guess!!
Ski in NC is online now   Reply With Quote
Old 11-24-2015, 07:02 PM   #26
TF Site Team
 
Pack Mule's Avatar
 
City: Paris,TN
Country: USA
Vessel Name: William
Vessel Model: Outer reef 32
Join Date: Jan 2013
Posts: 2,501
This is what's on mine , not sure what it does for me . Tag says 14v . I guess the PO did what needed to be done to mount it this way (facing the engine ) . I know very little about alternators.
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	36
Size:	107.3 KB
ID:	46819  
__________________
Marty
Pack Mule is offline   Reply With Quote
Old 11-24-2015, 08:42 PM   #27
Senior Member
 
djones44's Avatar
 
City: Salt Spring Island
Country: Canada
Vessel Name: Twilight
Vessel Model: Permaglass Sedan
Join Date: Apr 2012
Posts: 168
I'm dealing with battery charging issues at the moment (2xDD8.2L with Balmar) and I am downgrading the Xantrex 40a Truecharger to 20A. I don't want to boil my batteries (further) and I view 20A as a capable trickle charger, all I need betwixt weekend cruises for 4x8D new batteries. Or so I hope.

One question: My starboard engine when running makes a loud ticking sound somewhere up around my tachometer. It's a PITA when cruising and I have to track it down, but can't seem to do it using just audio, a steel rod, etc.

Could this is be an electrical noise generated by an alternator-based tach, or is it as mechanical as it sounds?
djones44 is offline   Reply With Quote
Old 11-24-2015, 10:22 PM   #28
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 10,179
Quote:
Originally Posted by djones44 View Post
I'm dealing with battery charging issues at the moment (2xDD8.2L with Balmar) and I am downgrading the Xantrex 40a Truecharger to 20A. I don't want to boil my batteries (further) and I view 20A as a capable trickle charger, all I need betwixt weekend cruises for 4x8D new batteries. Or so I hope.

One question: My starboard engine when running makes a loud ticking sound somewhere up around my tachometer. It's a PITA when cruising and I have to track it down, but can't seem to do it using just audio, a steel rod, etc.

Could this is be an electrical noise generated by an alternator-based tach, or is it as mechanical as it sounds?
If that 40A charger is a smart charger, you should have nothing to worry about regarding an excess charge. Once the battery reaches about 80-85%(Absorption stage), the acceptance rate has stepped down enough to only allow enough measured current flow.

Why are you downgrading?

I have alternator based tachs but hear no mechanical ticking. Don't know if your engine could handle this, but have you tried a brief engine run with the alternator disconnected to note any sound differences?
__________________
Al

Custom Google Trawler Forum Search
FlyWright is offline   Reply With Quote
Old 11-24-2015, 11:22 PM   #29
Senior Member
 
djones44's Avatar
 
City: Salt Spring Island
Country: Canada
Vessel Name: Twilight
Vessel Model: Permaglass Sedan
Join Date: Apr 2012
Posts: 168
Quote:
Originally Posted by FlyWright View Post
If that 40A charger is a smart charger, you should have nothing to worry about regarding an excess charge. Once the battery reaches about 80-85%(Absorption stage), the acceptance rate has stepped down enough to only allow enough measured current flow.

Why are you downgrading?

I have alternator based tachs but hear no mechanical ticking. Don't know if your engine could handle this, but have you tried a brief engine run with the alternator disconnected to note any sound differences?
The boat is on shorepower 95% of the time (tied up) and I am nursing a 1500W heater over the winter. I don't feel that I need 40 amps when I have Balmars, and an 8000 KW diesel generator, and the Xantrex is stackable and smaller now, I can add one with 60A alongside for 80A if I need to. I guess I'm from the old trickle charger generation, and on 30A shorepower.

Thank you for the suggestion re: disconnecting the alternator, I suppose that must come. Maybe when I put the new Xantrex in (the Statpower was dead) things will resolve themselves from there.
djones44 is offline   Reply With Quote
Old 11-25-2015, 12:06 AM   #30
Guru
 
C lectric's Avatar
 
City: Somewhere
Country: , Canada
Vessel Name: Island Pride
Vessel Model: Palmer sedan 32'
Join Date: Oct 2007
Posts: 1,870
Does your regulator have a max. output adjustment. Many do.

You may actually do better to turn down the max. output current to a lesser level avoiding overheating. If you are only getting a 70% duty cycle ,on/off, then less output may actually improve overall charging if the current is constant.
Try something like 80% output and test.
C lectric is offline   Reply With Quote
Old 11-25-2015, 05:33 AM   #31
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 9,996
Greetings,
8000 KW generator? THAT'S big.
__________________
RTF
RT Firefly is offline   Reply With Quote
Old 11-25-2015, 06:05 AM   #32
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,525
One hassle with shore power charging is long term overcharging.

The unit does fine , then an accessory , DC fridge or furnace switches on.

The voltage drop is enough to have the charger decide a full charge cycle is required.

Sadly many of these top out at 14,4v and switch to 13.4 to .8 to float.

This slight overcharge eats water , which can kill the batt.

Simple is HydroCaps which convert the gas back to water.

Simpler is to lower the charge voltage top and float settings , as all you really need is a bit above 12.6 or .8 to keep the batts happy all the sitting time.

With no power hose we use solar year round and simply set the V regulator to a lower float.
__________________

FF is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 02:02 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012