The Technical Committee is aware of a recall of Norcold 1200, 600 & 800 Series Gas/Electric.
Please refer to the recall notice posted in the Technical Library
x
I opted for the residential refrigerator option in my new Redwood because of the issues Norcold had with their 1200LRIM propane/electric refrigerators. I had one of these in my National class A diesel pusher and was scared to death of having a fire while I was away and my pets were inside the coach. Norcold's fix was to install an over heat sensor on the cooling unit that would shut the unit down in the event of cooling unit failure which could cause a fire. A band-aid fix for sure!
If you do have one of these units and want to keep it consider the following:
1.) Make sure you have the recall fix applied and the overheat sensor installed
2.) Add a Halon automatic fire extinguisher in the exterior cooling unit compartment.
3.) Consider replacing the cheap Norcold cooling unit with one of the Amish built cooling units.
2.) Add a Halon automatic fire extinguisher in the exterior cooling unit compartment.
I would have to disagree with this one. Halon is gaseous suppression agent that stops the chemical reaction of fire. It is only effective in an enclosed space that is not ventilated. When used in computer rooms, boat bilge, the activation of the Halon is always preceded by shut down of ventilation and closing of dampers to stop the airflow and allow the Halon to reach a 6% saturation to be effective.
Your gas absorption refrigerators rely on a natural ventilation flow from the lower vent to the top. Discharge of Halon into that space may put out the fire, but within seconds when the saturation drops below it's required amount due to continuous ventilation, the fire can re-ignite, often at a greater ferocity than it originally had when it was put out because the fuel that was feeding it was allowed to spread further while extinguished.
Dry chemical, slurry, foam, or a long duration water mist or just plain water are the only effective ways to suppress that fire, or automatic dampers that would close off those vents.
Hate to say, but there are a lot of backyard applications of safety products that prey on RVers.
Although I agree with you on theory regarding Halon gas and how it suppresses fire I don't completely agree with your assessment that this would not offer protection in the event of a catastrophic cooling unit failure.
It's important to understand exactly what happens to these cooling units that leads to fire. These fires occur when there is a quick loss of the hydrogen gas in the cooling unit from a sudden cooling unit breach (typically caused by corrosion failure). The hydrogen gas is ignited typically by the open flame of the burner pilot light. If this occurred the hydrogen gas is consumed quickly by the flash fire. As you said. the release of Halon into the compartment should displace enough oxygen temporarily to extinguish the flash fire and also the pilot light. The large quantity of hydrogen gas in the compartment would have been consumed by the original ignition leaving no residual gas for re-ignition.
It's important to understand that in most cases cooling units fail due to very slow leakage with the telltale ammonia odor or a yellow powdery residue and the hydrogen gas escapes in small quantities that are not hazardous. It's the sudden catastrophic in which the hydrogen is released suddenly into the compartment that typically causes these fires.
Personally I'd pay for the comfort and assurance that the initial flash fire was extinguished. Just my two cents.
https://rvcoolingunit.com/SS-30-Halon-Extinguisher-90-Degree-Auto-Deploy-P1872453.aspx
As you said. the release of Halon into the compartment should displace enough oxygen temporarily to extinguish the flash fire and also the pilot light. The large quantity of hydrogen gas in the compartment would have been consumed by the original ignition leaving no residual gas for re-ignition.
https://rvcoolingunit.com/SS-30-Halon-Extinguisher-90-Degree-Auto-Deploy-P1872453.aspx
You may be confusing Halon with Carbon Dioxide. Halon does not suppress a fire by displacing Oxygen, it suppresses fire by prohibiting the chemical reaction of combustion. If the other three elements are still there (heat, oxygen, fuel) and the combustion process is allowed to return through natural venting of the Halon, the fire reignites. As you said, the Hydrogen burned off within the first few seconds. By the time the Halon extinguisher reacted (thermal activation) the fuel source is now the wiring, plastic tubing, Styrofoam insulation around the fridge, plastic vent cover and wood. Halon does not offer the cooling effect of CO2, so the temperature is still there as well.
I believe it is a misapplication and false sense of security. There are better products out there that are a foam base that would do a better job.
One might pick up on the fact that Brad's occupation is Fire Safety .........
Originally Vaughan, but fire protection engineering for the last 17 years. Before that was the fire service for 21 years. However I in no way have a handle on it all and don't want to come across that way. Fire protection has never been a precise science.
The Halon issue sticks in my mind as I responded to two kitchen workers that were injured badly from from a re-ignition in a fryer. The owners had switched to Halon 1211 portable fire extinguishers everywhere in the building because they didn't require service for 12 years. When the fryer caught on fire, rather than pull the ring for the hood fire suppression, the cooks grabbed a Halon extinguisher and put out the fire, and of course they were hovering over it when it restarted, almost violently. The hood was still operating and it pulled the Halon gas right out the roof, leaving them in the middle of overheated fat just waiting for a new opportunity to ignite. The halon fire extinguishers should never have been in the kitchen - only Dry Chem.
That same scenario could easily happen in the RV if someone decided to replace their recalled Kidde dry-chem with a Halon thinking it would be better and easier to clean up.
