Date: Thu, 30 Dec 1999 09:27:41 -0800
Reply-To: Davidson <wdavidson@THEGRID.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Davidson <wdavidson@THEGRID.NET>
Subject: Re: More on the - '83 Westy Fridge Won't Light
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David,
On the other hand.....
When driving with the fridge on 12v (most likely time to use it that way)
and the temperature is high (the most likely time for me to go camping
and... when cooling counts the most), it is also most likely that the air
conditioning will be on.... having cooler air to circulate behind the fridge
and to lessen the demands on the fridge are perhaps even greater factors
than the ones that you mention. Maybe that's why I don't notice the fridge
being warmer on 12v.
Another 2 cents,
Bill
90 Westy Syncro
-----Original Message-----
From: David Beierl <dbeierl@IBM.NET>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Thursday, December 30, 1999 9:13 AM
Subject: Re: More on the - '83 Westy Fridge Won't Light
>At 09:11 12/30/99 , George Jannini wrote:
>> Dan, (and Todd), the green LED should work in both 12 volt and propane
>>operation. It does not light in the 110volt mode. In my experience, the
>
>Well...the green light is *supposed* to indicate that the flame is
>on. Because the VW (ground) wiring is marginal, and most especially if
>the ground connection isn't perfect, it also tends to light up when the 12v
>is running. However, that is an artifact and ought to be curable by
>perfecting the ground and increasing the wire size. That would also
>improve performance on 12v. Increasing the supply wire size as well should
>improve performance even more, possibly dramatically.
>
>Which reminds me, a reason I don't see commonly mentioned for the 12v mode
>to be less effective than 110v mode is that small resistances in the supply
>wiring and connections have a proportionately much greater effect on the
>heat output of the 12v heater than on the 110v heater. Theoretically the
>heaters have exactly the same output, but in practice the 12v tends to be
>less. I haven't got numbers b/c I'm too lazy to pull the thing out and
>measure voltage at the heater terminals, but that's how it works. Each
>half-volt drop at the heater will reduce the heat output by about 4 per
>cent. The same half-volt drop at the 110v heater comes to about 0.4 per
cent.
>
>In addition to that, I believe that the actual refrigeration cycle does not
>work as well when the box is being driven around. The whole cycle is
>gravity-based and depends on fairly gentle declivities to persuade the
>gases to flow down from the top of the reefer -- this surely is disturbed
>when the box is shaken and accelerated fore-and-aft. I have noticed an
>immediate drop in output whenever the vehicle starts moving, and I'm rather
>sure this is the cause. It is independent of the heat source -- gas, 110v,
>12v all show the same effect.
>
>david
>David Beierl - Providence, RI
> http://pws.prserv.net/synergy/Vanagon/
>'84 Westy "Dutiful Passage"
>'85 GL "Poor Relation"
>
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