Date:         Mon, 1 Jul 2019 10:28:26 -0700
Reply-To:     Neil N <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Neil N <musomuso@GMAIL.COM>
Subject:      Re: Some dometic notes
Comments: To: David Beierl <dbeierl@gmail.com>
Comments: cc: Al Bell <albell@shaw.ca>
In-Reply-To:  <CAMOH8LK7amUVNM4+jJrGd-tMUoMiNDcHPDgkFRaaTXm9ObAwuA@mail.gmail.com>
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Thank you for taking time to write that information David.

I now better understand the parts involved.

Kind of moot for me as I gave up on Dometic 182 fridges some years ago
but I really liked the LP aspect them. We all know how a compressor
style fridge can increase project costs (batteries, etc)

Neil.

On 7/1/19, David Beierl <dbeierl@gmail.com> wrote:

> The thermocouple output is proportional to temp difference between the two
> junctions.  But the output is either enough to hold the gas valve open, or
> not.  Certainly an eroded one is on the way to failure.

> ..... The
> thermocouple is basically two pieces of wire, so it has ridiculously low
> impedance.  That means that its tens of millivolts output can push IIRC
> better than one ampere through the magnet in the gas valve, which is only a
> few turns of heavy wire with pole pieces that are machined flat.  The
> actuator piece is also machined very flat, so that it makes extremely good
> physical contact with the pole pieces.  Because of the close contact the
> magnetic circuit is very good and the valve can be held open with
> considerable force.  But that force vanishes as soon as the two pieces
> break contact, so the valve has to be opened by you "pushing the pickle".
>
>
>>
>
> The thermostat is a snap-action device operated by that capillary tube.
> When it calls for cooling, it opens a clear channel for gas to pass through
> and be limited by the orifice.  When it does not, the gas for the pilot
> flame is metered through an extremely small orifice inside the gas valve.
> The flame has only two levels; cooling and pilot.



-- 
Neil n

VE7TBN

1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt

1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8

VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>