Message-Id: <3.0.3.32.19981003165102.00dd8204@olsusa.com>
Date: Sat, 03 Oct 1998 16:51:02 -0400
To: lancair.list@olsusa.com
From: ReganRanch@aol.com (by way of Marvin Kaye <marvkaye@olsusa.com>)
Subject: Alternator Power wiring
Mime-Version: 1.0

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>>
 Ed de Chazal's current question:

<<  Is it fine to go directly to battery
 positive (or similar node) with the fuse I have (or even without a fuse)? 
 Reason I ask is that it appears the 8-gage wire is good for 73Amps so I
wonder
 what good the 80 Amp fuse will be.   Incidentally, the factory wired the
panel
 with an alternator circuit breaker (I have both a 35A and 50A breaker I can
 use) that is ready to take the alternator feed if that is the way to go.  The
 B&C guy thought the 50A breaker didn't make sense given that it is a 60A
alternator. >>

The reason for a fuse in this case is to protect the wire from turning into an
8 gage hot foam cutter. A 60 amp rated alternator will only produce 60 amps
and not much more even running at full speed with the output shorted. The only
source for enough current to burn the insulation off of an 8-gage wire is the
battery. Therefore the wiring sequence should be: Battery-Master Contactor
(400 amp)-Fuse-8 Gage wire-Alternator. Mount the contactor and fuse as close
to the battery as possible (mine are on the battery box) to keep the dangerous
"Always Hot" wiring as short as possible. 

BTW: It bears repeating that when you connect a battery you should hook up the
ground last and disconnect it first. This way if your wrench touches anything
grounded when it is on the terminal you won't be treated to a spectacular
demonstration of Ohms Law. Been there, done that, got the T-shirt:(


Brent Regan