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RE: Battery cut-of switch

To: James Nazarian Jr <James.Nazarian@Colorado.EDU>
Subject: RE: Battery cut-of switch
From: "Dodd, Kelvin" <doddk@mossmotors.com>
Date: Wed, 9 Feb 2000 16:17:52 -0800
James:

        Please disconnect the chassis side of the battery first.  This is
somewhere where hopefully you can learn from the mistakes of others.  I once
welded a perfectly good wrench to a Mini race car.


        This is from the Revised 1/73 SCCA rule book as used for SCCA
Vintage Racing.  Please excuse the typo's. It was dictated over the phone,
and my typing is not that good.

Master Switch

        All cars except show room sports cars and show room stock sedans
must be equiped with a general circuit breaker (master switch) easily
accessable from outside the car.  This circuit breaker will cut ALL
electrical circuits (ignition, fuel pumps, lights, alt, etc) but not an
on-board fire extinguisher.  It shall be clearly marked by the international
marking (spark and blue triangle) (Note: regions order from Denver)  and
mounted in a standard location.  The standard locations will be as follows.
A formula and sports racing cars In close proximity to the right hand
upright member of the roll bar, but in a location so that it cannot be
operated accidentally.  It can be mounted on a bracket, welded to the inside
of the upright member, or mounted such that the operating lever or knob is
outside of the body panel immediately inbouard of the upright member.  This
is the standard location for formula cars built to the contractors assoc.
requirements for formula 1.  B  Closed sports racers, production cars,
coupes and sedans.  In front of the windshield, on either side of the cowl
or on top of the fender, but close enough to the windshield to be accessible
if the car is overturned.  Alternitively it may be mounted below the center
of the rear window. C.  Open production cars.  May excercise a choice among
above locations.

Revised 1/73 SCCA rules for vintage racers.


Kelvin.

> -----Original Message-----
> From: James Nazarian Jr [mailto:James.Nazarian@Colorado.EDU]
> Sent: Wednesday, February 09, 2000 3:39 PM
> To: Max Heim
> Cc: MG List
> Subject: Re: Battery cut-of switch
> 
> 
> I have always disconnected + side of battery (on - ground car) when
> working.  I don't know though.  To some of the racers:  do any of the
> class rules specify where the switch is (+,-)?  I suppose 
> that in practice
> there isn't much of a difference which side of the battery 
> the switch goes
> on.
> 
> James Nazarian
> '71 B roadster
> '71 BGT rust free and burnt orange
> '74 BGT going by-by soon
> '63 Buick 215 
> 
> On Wed, 9 Feb 2000, Max Heim wrote:
> 
> > Hmmmm... by that logic, you would always disconnect the 
> "hot" battery 
> > cable when working on your engine. Tried that once (wasn't thinking 
> > clearly), and my wrench touched the rim of the battery well 
> while I was 
> > loosening the nut. Needless to say, I won't do that again.
> > 
> > As for your argument, either way cuts the circuit. The 
> idea, however, is 
> > not to have the frame of the vehicle connected to the 
> battery, as the 
> > frame is a much bigger "target" for generating shorts, 
> compared to the 
> > starter/ignition leads (see example above).
> > 
> > James Nazarian Jr had this to say:
> > 
> > >I disagree.  I would want it on the hot side to cut off 
> power.  Part of
> > >spec for the placement of the switch in race cars is that 
> it must be close
> > >to the battery.  This, I beleive, is to cut off power to 
> the hot lead to
> > >not only stop engine, but remove power from wiring so that 
> there are no
> > >shorts that could spark against the body as start a fire. I think.
> > >
> > >James Nazarian
> > >'71 B roadster
> > >'71 BGT rust free and burnt orange
> > >'74 BGT going by-by soon
> > >'63 Buick 215 
> > >
> > >On Wed, 9 Feb 2000 Ajhsys@aol.com wrote:
> > >
> > >> In a message dated 2/9/00 3:21:33 PM Eastern Standard Time, 
> > >> doddk@mossmotors.com writes:
> > >> 
> > >> << The battery cut off switch can be on either the hot, 
> or ground lead.
> > >>  Since this is something that is getting stuck into the 
> car, the ground side
> > >>  would be safer, as the exposed terminals will not be a 
> shorting hazard. >>
> > >> 
> > >> - - - - - - - - - - - - -
> > >> 
> > >> That makes sense.  All the switches I've seen have big 
> exposed terminals on 
> > >> the top.  I guess you could use the cable boots that are 
> used on starters 
> > but 
> > >
> > >> they never seem to fit very well.
> > >> 
> > >> Thanks, Kelvin.
> > >> 
> > >> Allen Hefner
> > >> SCCA Philly Region Rally Steward
> > >> '77 Midget
> > >> '92 Mitsubishi Expo LRV Sport
> > >> 
> > >
> > >
> > 
> > 
> > --
> > 
> > ===============================
> > Max Heim
> > mvheim@studiolimage.com
> > Studio L'Image/San Francisco
> > 415 643 9309 : 415 643 9307 fax
> > Studio L'Image/New York
> > 212 242 3366 : 212 242 3399 fax
> > 
> 

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