[T3] Ignition on with points closed.

[Dave Hall]

Thanks for the reassurance, Don.

I've found the Type 3 points have been pretty good, apart from a set with a
white nylon heel that wore away very quickly. I've never changed the
original condensor or the original black coil; they don't even seem to
suffer much from spark erosion.  Must be well-matched for LC.

Dave
UK VW Type 3&4 Club
===================

-----Original Message-----
From: type3-vwtype3.org [mailto:type3-vwtype3.org-bounces at lists.vwtype3.org]
On Behalf Of Don Robertson
Sent: 30 March 2016 14:01
To: type3 at vwtype3.org
Subject: Re: [T3] Ignition on with points closed.


Alrighty then...  lets get more specific.  The problem occurs when (as it
true of ANY electrical connection) the points are not completely closed, but
when they are sitting more of less closed, but loosely.  If they are
completely open, or completely closed with a good connection, there will
probably be no problem.  As with any electrical connection, looseness causes
arcing and heat.  For instance faulty electrical connections in an old house
have caused fires.

In a 6 or 12 volt system there is not enough current to cause a fire, but
there is enough to cause a pit to appear on one half of the points surface
and a cavity on the other.  "Burned" was a poor choice of term.  If the
points actually look burned, i.e. ruined with evidenced of black soot, the
condenser is likely at fault.



At 08:16 PM 29/03/2016, you wrote:
>Don, please explain how the points will get burned even if they are 
>closed while the ignition is on and the engine is not turning.  
>Virtually all the energy would be dissipated in the 4 Ohm primary coil 
>winding, and while I've never measured the resistance of a set of 
>points, I can't believe it could be more than a tiny fraction of the 
>coil resistance, maybe 0.1 or 0.2 Ohms, so don't see how there could be 
>a significant amount of heat dissipated in the points, let alone enough to
burn them.
>I've never experienced burnt points even though the ignition would have 
>occasionally been on for some time, eg when adjusting headlight aim, 
>and I've never bothered to ensure the points are open.  Certainly the 
>coil would warm up, as it dissipates about 40W with the engine static, 
>and about 20W when running (figures from Motor Industry Research 
>Association report on
>1969 FI Auto Fastback), so unless your hands are cold, there's no 
>advantage in it!
>
>Obviously there's no gain leaving the ignition on unnecessarily, but I 
>can't see how it would be a problem for the points, which are 
>essentially just switch contacts.  Please explain if I'm showing my 
>ignorance, but it sounds like something told to apprentices to 
>emphasise the need to turn off the ignition and avoid flat batteries.
>
>
>Dave
>UK VW Type 3&4 Club
>===================

Don Robertson - (905) 566-0000
3641 Wolfedale Road, Mississauga, Ontario, L5C 1V8
Skype: marinemarketplace
Government is the great fiction, through which everybody endeavors to live
at the expense of everybody else.
- Frederic Bastiat, French Economist (1801-1850)

Webmaster:
peoplepost.net - marinesurveyor.com - yachtsales.com - condowebsites.net
Click Here http://www.marinesurveyor.com/websites.html for a list of over
100 Marine Surveyor Clients.

Listmaster
http://www.marinesurveyor.com/boatpokers/ - Boatpokers - A private email
forum for SAMS members http://www.surveyorexchange.com/ - The Marine
Exchange - The Marine Technical Email Forum For Professionals Employed in
Marine Industries. 

_______________________________________________
VWType3.Org mailing list - type3 at vwtype3.org To unsubscribe or change
subscription options, visit:
http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
If you need more help, contact: gregm at vwtype3.org


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus