Cruisers Forum

Join CruisersForum Today

  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 12-04-2016, 09:02   #16
Registered User
Dsanduril's Avatar

Join Date: Aug 2011
Location: South Africa, Toward Caribbean
Boat: Outremer 50S
Posts: 1,745
Re: alternator direct to house bank

Originally Posted by dave777 View Post
What size fuse/breaker would you use on a 60A alternator Yanmar 3YM30 engine? Also thinking of upsizing to a 100A alternator.

Don't know if alternators put out surges of current in some conditions, which could complicate things.

I'm thinking that I'd put in a switched breaker so it would serve to dual purpose of depowering the line to the alternator when working on the engine.
The 150% cited above it about right. For a 60A alternator you could go 80A or 100A on the fuse. I'd probably select 100A.

One problem with breakers is their fault clearing capability, that's why fuses are recommended. A dead short on a battery can provide a tremendous fault current (could be thousands of Amps). With a high enough fault current you can actually weld the contacts of the breaker shut, or with DC simply arc between the contacts, and the breaker doesn't do its job. You need to look at the DC interrupting current rating of the breaker and then at the available fault current of your battery system and make sure the interrupting current rating is higher than the available fault current (the same is true for fuses as well, but fuses generally have a much higher IC rating than breakers). For most battery systems you are better off with a switch and a fuse rather than a breaker.

Dsanduril is offline   Reply With Quote


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
36vdc Motor Bank and 12vdc House Bank bobola Electrical: Batteries, Generators & Solar 24 22-12-2009 21:30
House Bank or Genset-Engine Bank? BlueSovereign Electrical: Batteries, Generators & Solar 11 24-04-2009 16:11

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:52.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.