I think that would not be a problem. On my House Bank, I have a
master isolation switch. The LN alternator is connected to the
'downward' side of this switch. So, opening the Master switch causes
all to be disconnected from the house battery, including the LN
alternator. (All except the bilge pumps, they are wired directly to
the House Battery with separate wiring)

On the Starter Battery I have no switch on it, so no need to worry
about the field on the stock motor alt. 11.7.1.2.1. calls out that
no isolation switch is needed for batteries under 800 CCA. Note also
that exception 2B allows 'battery Charging equipment' to be directly
connected to the batteries, even those over 800 CCA. Note also that
exception 2B allows for direct connect of the bilge pumps. So, all
is OK with ABYC specs.

I do feed the LN field through the House Battery master switch. That
is easy as I have converted it to an external regulator (as you said
you did also). But in practice I never touch this master switch. It
truly is there only for emergency and maintenance use. When leaving
the boat I turn things off by the Sub Panels.


BTW: These LN alternators are tuff things... Real 'large frame', can
get them for around $250 or so on eBay, and my alt puts out 145A at
idle (Hot and measured). And if you need more current, just run two
in parallel

Also, have really enjoyed watching your progress and your web site.

-al-


On Sun, 19 Feb 2006 19:58:36 -0500, "Glenn Ashmore"
wrote:
SNIP
Everything has to conform to ABYC standards and 11.7.1.2.1. says
I have to have a way to isolate the house bank from everything else or I
will get a nasty letter.