Date:         Fri, 29 May 1998 08:11:17 8
Reply-To:     Wes Neuenschwander <wesn@ESKIMO.COM>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
Comments:     Authenticated sender is <wesn@mail.eskimo.com>
From:         Wes Neuenschwander <wesn@ESKIMO.COM>
Subject:      Re: Westy fridge efficiency in 12v mode
Comments: To: Kelly Bauman <bauman@ICAN.NET>, vanagon@vanagon.com

> Date:          Thu, 28 May 1998 07:51:33 -0700
> From:          Kelly Bauman <bauman@ICAN.NET>
> Subject:       Re: Westy fridge efficiency in 12v mode

> At 16:21 27-05-98 -0400, Gregg Scharff wrote:
> >        Does the fridge pilot light stay lit during all driving conditions?
> >        So, does that mean that the 12v mode is only for backup purposes when
> >propane runs out?
> >
> >Gregg (Conshohocken, Pa)
> >'85 Westy
>
> There is no pilot light.  This is why you have to do the "pump and click"
> song and dance before starting the Dometic.  Also, when you turn off the
> propane at the tank, this shuts off the fow of gas that would be needed
> to keep a pilot light lit.
>
> Kelly Bauman
> Delta, BC
> '91 Westy
>

Actually the Dometic 182 series fridges - standard gear in most Westy's -
have the functional equivalent of a "pilot light".  Propane in the
Dometic 182 fridges is piped through the thermostat valve  to a gas
"safety device", which contains a "proof of flame" sensor, before passing
to the burner assembly.  The thermostat does not have a shutoff, so that
even in the Min setting a small quantity of propane will be allowed to
flow.  So as long as the main gas cock is on, and the gas safety valve
senses a flame, gas will continue to flow, maintaining a small, pilot
sized, flame.

While this may not be a pilot flame in the conventional sense - pilot
flames in most appliances have a separate pilot gas line and special,
match-size burner - the Dometic system serves the same purpose, just with
fewer parts (and is indeed referred to as a "Pilot" in the Dometic
service manuals).

The Dometic fridges - at least the later models - do have an electronic
ignition system which will automatically attempt re-ignite the flame if
the pilot goes out.  However, this is a backup to the main flame safety
control provided by the gas "safety device", not the primary control.
And of course, if the electronic ignition fails to re-ignite the burner,
the flame safety device will sense loss of flame and close the flame
safety device valve.  The only way to restart the burner at this point is
to push the flame safety device button, bypassing the safety shut-off
valve. Once the sensor "proofs" the flame, the button can be released and
gas will continue to flow.

-Wes


Wes Neuenschwander
Seattle, WA
wesn@eskimo.com