[Archived]

Bob, thanks for the kind words.

Jon, thanks for the invite to talk about my fire detection system.

Just a bit of background. In 2004 we started a business called RV Safety Systems. The primary product was our fire detection system, but we also sold tire pressure monitors, fire extinguishers, SilverLeaf, etc. We closed that business last year. However, I am still quite involved in the fire detection system technology and still sell the units (albeit at a very low level of marketing {grin}.

I decided the best way to let folks know about my system was via my website. After we closed RV Safety Systems, I obtained a new domain: http://firedetectionguy.com/ . I let that site sit vacant for quite a while, but finally got off my duff and put some information on it over the past few days.

Please forgive the somewhat un-organized look of the site right now. I am doing this in WordPress and it is taking some time to figure out how to optomize the power of that product.

Jim

[Archived]

Very nice.

Care to share price information. most of us have engine compartment alarms, some have fire suppression systems in the engine area but nobody I know of has any alarms or fire suppression for the generator.

The display could prove very helpful because as every pilot knows, once we have a benchmark piece of information, such as normal temperatures a rise or deviation from that could prove to be an early warning, even if the alarm limits were not reached.

[Archived]

Looks like a great product Jim. Do you have a wireless version on the market?

[Archived]

Jon, thanks for the kind comments.

I did not include the price in the data, as I was agonizing over
how to price the product. When I had the business, I had to
price the product to cover the terrible overheads I was
encountering. I no longer have to address those issues. I
finally arrived at $595 for the FD-400 and $795 for the FD-400-5.

Fred, we looked at wireless, but I just did not feel comfortable
with the reliability of the technology at the time. There is a
lot of electrons flying around in our coaches {grin} and a lot of
shielding as well. One of the objectives of the next generation
will be to look at wireless. It will be a university project
and they have some pretty good technology and testing capability.
In the end we still may not feel comfortable with the reliability.

I had mentioned that we were also going to focus on compatibility
with CAN technology. Jon pointed out that many of your coaches
don’t have that technology (nor mine). However, many of you
have SilverLeaf products. Martin Perlot and I have discussed
adding the technology to his systems (easy task for him, hard task
for me).

Also as noted, many of your coaches have fire detection systems.
My coach also has a fire detection system from the factory.
When I hit the check button, it says it is working. I know for
a fact that it is not. I always talk about passive and
active systems. Our factory coach detection systems are what I
call passive. They don’t let you know that they are working
– you just take it on blind faith. I was not comfortable with
that approach. The system I designed is active. You can
see the temperatures and it lets you know if there is a fault in the
sensor wiring system.

As long as I am hogging the bandwidth, I wanted to mention a neat
application of the technology. I used one of my five sensors to
measure the Aqua-Hot boiler temperature. I threaded a sensor through
the gasket for the fill spout and down the side of the boiler. It is
very accurate (based on published shut off values from Aqua-Hot). It shows
187 degrees when the heat source shuts off.

Thanks for letting me ramble.

Jim

[Archived]

Most don’t realize it, but some of their coach systems do use the CAN Bus or the RV-C protocol. Some manufacturers just don’t want you to know if because they are in the business of selling their remotes and don’t want to advertise they use an open standard. A shared physical layer and common protocol stack are inevitable in coaches, especially higher end coaches. This is already commonplace in the marine industry, and I understand it to be the same in the aviation industry, although I can’t speak to the aviation industry.

Unfortunately, the economy really hit RV-C from being widely deployed and I hope to see it more widely adopted and marketed in times to come. As far as I can tell, SilverLeaf is really the company that has done the most for the world of RV-C and it’s possibilities. Take a look at their total coach management system and you’ll get a sense of how much can already be done. If you’d like to see more on RV-C, here’s a link: http://www.rv-c.com/?q=forum/1

[John]

I believe Prevost coaches since 2007 are multiplex. I believe current Liberty product has been multiplex. But most of our coaches are not. From an owner’s point of view I don’t think it matters, but from a technician’s perspective multiplex systems have huge advantages.

I have an interest in Jim’s system because I went through a bus fire that might have been easily extinguished if it had been detected earlier. Still trying to figure out how to best utilize the features and where to put the display in the coach.

[Greg]

Wow, interesting thread. I especially enjoyed the photo’s, of particular note was the use of water on this type of fire. Personally I carry a 20 lb bottle of Halon 1211 and a 30 lb Ansul Dry Chem in the belly. Topside I have a three small dry chem and a small water fire extinguisher.

Probably not a half bad idea for folks to review the appropriate extinguisher to select for a fire, cloth, upholstry use the water bottle. Galley fires use the dry chem. Should the engine area be ablaze I would dump the Halon into it followed by a brisk jog in the opposite direction, followed by a call to the fire department and my insurance carrier!

Now as to fire detection/protection…..been around these systems for years on airplanes where both can be super critical. The downside to these is I do not know of any that are maintenance free and most require action by the operator (pilot’s). Nearly every airliner is protected either by a continous loop (thermo couple) around each engine, inside the cowling (under the hood) or a sensor-responder. All that those systems do is to ring a bell or tone (very loud) and to illuminate a lite as to the location of the fire, once again triggered by a heat sensitive loop that will complete the circuit at a predetermined temp. The operator then makes the decision as to whether to fire the appropriate bottle. The wheel wells are also somewhat protected better said they have fire detection, not protection. While not common brake fires do happen and one of the items accomplished by the ground crew on departure is rotation of all wheels, probably not a bad idea with the bus as well, just verify that all tires are truning before jumping onto the interstate. There is a plethora of engineering in these systems yet false warning still remain a common problem Fire detection is often ac powered while protection is always powered right off the ships battery.

Back to the bus, there are so many potential areas for fire it would be nearly impossible to isolate them all. I would be willing to be that a large percentage of fires are caused by either faulty or lack of maintenance. The circuit breaker systems should take care of nearly every electrical issue long before it procedes to fire if they are operating correctly. Unprotected circuits should either be protected by breaker or fuse or removed. I could go on……………………….

[Archived]

Discussion of fire extinguishers can often bring out diverse
opinions.

Certainly Halon is among the very best — in an enclosed
environment. It displaces the oxygen. In an open area,
the oxygen is quickly available to support the fire. That is
the reason I did not use it for the engine and generator
compartments. I have installed halon systems with temperature
sensitive heads in the bays of coaches. Most folks think
that Halon had been “outlawed”. Only the production.
You can buy Halon extinguishers all day long.

Mac the Fire Guy and I were “friendly” competitors when
we were in business. We didn’t agree on many things, but we did
agree that dry powder extinguishers are marginal at best. There
are lots of different powders used. All create a terrible
mess. Some can cause terrible corrosion problems – especially
in electrical systems. Pound for pound they are not nearly as
effective as the newer foam/surfactant systems.

I sold Cold Fire. I was at the first NHRA race, working in
the shutdown area, when the Cold Fire guy showed up. They first
put it on the chase trucks and then certified it for use in the
cars. I witnessed first hand how amazing the product was.
When I went in business, I did my own testing. One 2.5 gallon
extinguisher put out three tire fires (three tires in a burn tank
with gas/diesel mixture). Here is the details on a backdoor
link to my old website: http://www.rvsafetysystems.com/Handheld%20Fire%20Extinguishers.htm.

I just learned that Cold Fire is now certified for Class D
(flammable metals including magnesium)

Jim

[Archived]

All very good points Jim. By no means am I an expert on this topic rather familiar would be a better statement. Regarding the Halons I do believe there are two flavors, 1211 and 1308. 1308 is the gaseous Halon whilst 1211 is liquid. I do know that 1211 is used inside of the “rather breezy” engine cowls of jet aircraft and apparently is satisfactory. I would suspect that the ability of Halon to douse a fire is directly proportional to the amount applied at scene, 20 lbs is quite a load of the stuff! I still stick to my premise that I would dump a 20 lb bottle and run because if that did not do it there is probably nothing anyone can do in a hurry, save call the fire department. Further the little bottles of Halon are probably of no particular use on anything bigger than a very small kitchen fire.

I agree with the dry chemical analysis, works good but really leaves a mess, as you mentioned often corrosive. I have 5 gallons of Trident AFFF Foam concentrate by Argus but have not done much with it. By far, foam is state of the art for firefighting, especially if you are a fireman.

Finally I think it important the folks have a general concept as to what type of extinguisher to use where. The garden hose on the bus engine is a shinning example…………

[Archived]

I do know one thing from my experience, if steel parts are directly in line with a flame (burning oil, freon, fuel, etc) and they get cherry red as the clutch on my OTR compressor did. Extinguishers put out the flame, but as soon as the extinguisher was empty the material that was burning (freon in my case) immediately reignited. To add to the smorgasbord of burning materials the fire burned through the hose from the oil reservoir and that started fueling additional fire.

The only thing that would cool things down enough so the fire would not re-ignite was repeated dousing with water drained from the water tank. The fire was so hot that after we thought we had extinguised it smoke was coming from the air intake. It turned out that even though the air filter element was never in contact with the metal housing the paper element burst into flame. I had to use my socket wrench to remove the bolts and pull the air filter from the housing.

The fire department arrived about 20 minutes after we had the fire out and one of the firemen gave me hell for using water. He was not amused when I pointed out if he had been there on time I would have yielded to his expertise.

I am now of the opinion if I can learn of a fire before it has gotten materials above the ignition point the outcome is going to be very different than if I am unaware of it for a period of time.

[glen]

Jon,

Hate to inform you but freon does not burn. they used to use it in fire extinguishers……….Gotcha!