Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 23-05-2019, 01:46   #1
Registered User
 
mtompson's Avatar

Join Date: Sep 2013
Location: UK
Boat: Jeanneau Trinidad 48
Posts: 148
Testing twin alternators

Hi all
With engine running and testing the voltage off the back of each alternator, can I tell if they are both out putting what I read, or if one was not charging would it still read the overall system voltage?
Is the only way to be sure, remove belt from each in turn?
Cheers
Mark
__________________

mtompson is offline   Reply With Quote
Old 23-05-2019, 02:48   #2
Sponsoring Vendor
 
Neptune's Gear's Avatar

Community Sponsor

Join Date: Oct 2012
Location: Gulf Harbour, New Zealand
Boat: Farr Phase 4, 12.8m
Posts: 1,100
Re: Testing twin alternators

Alternators produce amps. Put a clamp meter on the output cable, and read the amps. That will tell you the output of each alt. If you really want volts, then you will have to disable one at a time - belt off or field off. The Voltage level is set by the regulator...
__________________
Matt Paulin
Neptunes Gear Ltd
www.neptunes-gear.com
Neptune's Gear is offline   Reply With Quote
Old 23-05-2019, 02:53   #3
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 34,989
Images: 240
Re: Testing twin alternators

First, test voltage /w alternator not running.
Then, test /w alt's running. There should be a significant increase in voltage when running.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 23-05-2019, 03:30   #4
Registered User
 
mtompson's Avatar

Join Date: Sep 2013
Location: UK
Boat: Jeanneau Trinidad 48
Posts: 148
Re: Testing twin alternators

Thanks guys, yes I need to get one of those clamp meters, in the meanwhile I guess to be sure Iíll have to take the belts off, which is a load more hassle, maybe Iíll try and borrow a clamp meter until I have the funds! Cheers
mtompson is offline   Reply With Quote
Old 23-05-2019, 21:58   #5
Registered User

Join Date: Jun 2013
Location: canada
Posts: 2,483
Re: Testing twin alternators

if they both go to the same battery. then if one is working and one is not. you will still get a high voltage on both because they connect to same spot. if they go to different batteries. then the voltage would only go up on one. assuming no ACR / VSR / or battery swtich on parallel

the best way would be with a clamp on amp meter.

note most alts don't do much at idle and need to be reved.
smac999 is offline   Reply With Quote
Old 24-05-2019, 00:55   #6
Registered User
 
mtompson's Avatar

Join Date: Sep 2013
Location: UK
Boat: Jeanneau Trinidad 48
Posts: 148
Re: Testing twin alternators

Got it, thanks everyone.
__________________

mtompson is offline   Reply With Quote
Reply

Tags
alternator

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Twin Gas vs Single or Twin Diesel Banjohans Engines and Propulsion Systems 4 04-10-2011 10:50
Load Testing and Conductance Testing Joe500 Electrical: Batteries, Generators & Solar 0 02-12-2009 15:12
Twin Alternators privileged Electrical: Batteries, Generators & Solar 2 21-04-2009 16:24
Center board vs keel vs twin keel vs twin centerboard jscott Monohull Sailboats 32 26-03-2009 14:48



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 00:22.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.