[HomeBrew] Need Idea

[N2EY@aol.com]

See end of this email for an alternative solution.

I agree with the idea of an electrically operated gas
shutoff valve operated by a timer IF certain conditions are met. A quick Google yielded the Asco 2/2 series HV266 as a possible candidate. 

Things to think about:

1) She Who Must Be Pleased has to approve the idea. Basically what we're envisioning is some sort of timer that must be set in order for the stove to work. Adds a step to the process - if you want a cup of tea, set the timer for ten minutes. If you're making the 25 pound turkey, set it for four hours. 


2) Must be easy to use. A simple dial timer?

3) All safety codes and gas company requirements must be met. Plus insurance.

4) (This is the biggie - do NOT assume the code and safety folks will pick up on this!)

How does the stove (and system) behave if the gas supply is interrupted while cooking, either in the oven or on the rangetop? Will the burner relight, or will the gas shut off, or will it pump out unburned gas? My old gas range had electronic ignition, and while the oven was thermal-interlocked to prevent simply pouring out unburned gas, the burners were not. 

Here's the problem:

Suppose a burner or the oven is left on and the electric power fails. Naturally the gas valve will close and shut off the gas supply. But suppose an hour later the power comes back on and the valve reopens - will the burner or oven relight, or will unburned gas simply pour out? 

One solution is to arrange the timer and valve control so that if power fails the timer resets to off and has to be reset manually to get gas flowing again. Might require an auxiliary relay. 

This is an important safety consideration because of
the scenario where something is left on, everyone goes to bed and the power fails for a time while everyone's asleep. Have to decide which is more risky - leaving the oven on all night or depending on the shutoff system to work in every conceivable power and hardware failure scenario.

----

Another solution:

Install some sort of thermal switch in or on the oven that closes at about 150 degrees F(IOW, whenever the oven is on, but not so low that a really hot day will close it. This switch controls a big red indicator (or several) that say "OVEN HOT", so that you don't have to squint at the knobs or indicators to see if the oven is off or not. Problem is that switch and wiring have to be able to withstand the highest temperatures the oven can reach.

-- Simpler version: Green light that only comes on when oven control is in OFF position. Red light comes on when green light is off. If you don't see green, don't go to bed. 

-- One more solution:

Electric stove with timer-operated cutoff relay (ugh - I prefer gas stove)

73 es be safe de Jim, N2EY









In a message dated 2/4/2004 12:27:40 PM Eastern Standard Time, zuu6k@juno.com writes:

> 
> 
> How about setting a timer for the length of time she expects to be using
> the oven? When it times out it closes a gas valve and lights an
> indicator. I seem to remember from 50 years ago that B-60 is the number
> of an electrically operated gas valve. Good luck.
> 
> Ed Richards K6UUZ
> 
> 
> On Wed, 4 Feb 2004 09:20:46 EST K6TFZ@aol.com writes:
> > ** Please do NOT cross-post messages to multiple mailing lists on the 
> > "To:" or "CC:" line of the e-mail message. **
> > 
> > Off topic but definitely homebrew.
> > 
> > My wife cooks a lot. She operates the ovens late at night after I'm 
> > asleep. 
> > Many times
> > she forgets to turn off the oven(s) when she is finished. The ovens 
> > are gas 
> > with electric
> > ignitors. There are pilot lamps on the front panel which light when 
> > calling 
> > for heat. The
> > lamps turn off when the oven reaches temperature.
> > 
> > She may open the oven door to look or to test, but that doesn't mean 
> > that she 
> > is
> > finished using the oven.
> > 
> > Need suggestions for some type of alarm to turn off the oven when 
> > finished.
> > I don't mind making some type of adaptation.
> >