Date:         Sat, 22 Sep 2012 23:13:13 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Alternator continuous-duty rating?
Comments: To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
In-Reply-To:  <505E4C90.5050409@gmail.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 07:41 PM 9/22/2012, Rocket J Squirrel wrote:
>I don't think the 90-amp rating is a continuous rating. It's probably
>peak rating, or one-hour rating or something, but not continuous. I'm

Just some context - with 90 amps at 13.6 volts, assuming 85%
efficiency the alternator will be sucking down about two horsepower
from the belt and dissipating about 225 watts as heat.

I don't know how much the water pump uses, but you're definitely
pushing the edges of what most marine folks recommend driving with
one automotive vee belt, especially the 3L size that we use.

There's a little calculator at
http://www.gizmology.net/pulleysbelts.htm for required tension and
such.  Only set up for two-sheave systems, but it's something.

I took squint around www.gates.com for hp ratings and got nowhere
useful.  Stopped short of asking an engineer, which they provide for
on the site.

Yrs,
d