Fire Fire Fire Alarm

[Gina Marie]

I recently had my turbo blankets changed. The new blankets on the 6v92 gave off a burning ordor. The salon and the engine room after and during use had this smell but it is wearing off after being installed for three days. Today after travel from Hillsboro inlet to Boca Raton inlet appox. 10 miles or so or about 30 minutes of travel at 1800 rpms upon entry to the inlet my fire alarm went off. Talk about priority, navigating the inlet with an out going current and the fire alarm indicator warning light and buzzer sounding, I had my hands full. Once I navigated through the Boca Raton Inlet bridge and was out of the pull of the current I immediatley stopped ran down stairs, I first opened the fire port hole and no smoke and no heat. I then openned the hatch slowly and again no smoke and no heat. Smell and a slight haze yes. This all happened with 5 minutes.

The fire system is connected to heat detectors in the engine room. Heat detectors are fused items and to trip they need heat, once tripped sinced fused system should not reset. Is that right??????????????????????????

After a few minutes the system reset.

How does this system work?????????

Why would the fire system trip and reset.?????????????

I have a Halon system and I don't think I have smoke detectors.

Is it a coincidence that the smell from turbo blankets and a faulty fire buzzer all happened at the same time.

What makes the fire warning buzzer and light trip??????????????????

Confused Gina Marie /Tom .

My warning light on the helm continued to remain on that with the buzzer.

[captddis]

You probably have the temp sensors mounted under the salon sole. There are probably a couple. It is just a temp sensor and will come on when temp gets to 160 [I think} and go off when the temp comes down. It sensed heat so determine why! Maybe a exhaust leak or a gap in the new blanket. If needed run the boat and have someone monitor the engine room to determine the cause.

[Gina Marie]

Thanks for the advise can you tell me what is a salon sole?

[captddis]

The floor in the salon.

[Nonchalant1]

Be careful watching in the engine room if you have a halon system. If it thinks there's a fire and goes off while somebody is in there, they can be snuffed out like a fire! I MEAN DEAD....SNUFFED OUT. You only get a few breaths of CO2 or halon, because there's no oxygen in what you're breathing, before you pass out. If you pass out in the halon or CO2, it's all over.

My CO2 system just senses heat, and it sets off the 75 lb CO2 tank first and that tuns on the helm station fire alarm. The reset is a manual push button on the CO2 pipe pressure sensor. Yours is obviously different.

Doug

[Genesis]

My boat has two heat sensors in it.

One of them was in a VERY bad location. Right near an exhaust elbow. Run hard, in warm enough weather, and it would trip. There was no fire, but man, the first time that happened it got my attenton FAST!

I moved it. No more problems.

Check carefully to make sure you don't have a gap in a blanket or a real hazard. If your system is like mine it has no connection to the fire bottle at all. Its just a heat alarm in the engine room, and SHOULD go off at 160F.

Sometimes people change these out for 125F sensors. That's a bad move; the 160F ones are correct for an engine room. 125F is quite easy to hit in an engine room on a hot summer day!

The switches are Airpax thermoswitches and self-reset when they cool down.

Oh, on the fire extinguisher, the CO2 is bad news if it goes off. It will both get you by asphyxiation and also will reduce the visability in the compartment to zero from the vapor cloud (it will basically SNOW Co2 in there!) along with causing extreme frostbite if you get hit by the discharge. Bad all the way around if you're in there when it goes off.

REAL Halon (e.g. 1211) will not kill you. However, if it gets hot enough being used on a real fire, the products of its decomposition can (its a phosgene-like compound!) so you don't want to be in there when it goes either.

FE241 and related "new" clean agents are an unknown. Some are supposedly human-safe, others not.

I don't want to be in the compartment with a discharging fire bottle no matter what's in it.

[captddis]

Co2 will definately kill you. Halon is generally safe unless it gets run through a diesel engine then the exhaust is poisinous. I know a couple people who had halon discharge when they were in the engine room, other than being startled suffered no harm. I treat Co2 systems with respect and let the pros arm them.

[Liquid Asset]

Genesis,

I was trying to figure out how the light/buzzer on the dash worked when I had the fire inspection done this year. The fire guy was setting the bottle in the discharged mode, but it was not setting off the light/buzzer on the dash. BUT, the test light shows it was working. I am now thinking that hte temperature sensor (Round Red Dome) mounted on the salon floor is what you are refering to. I have the CO2 Kiddie system. Does that sound like what your system was before you changed to the safe fire suppressent

[Genesis]

No - the round red dome only fires the CO2 bottle. Look for a small (about 2-3" diameter) plastic sensor with a ~.5" metal cap in the center. Those are the heat sensors and should have two wires going to them. On my boat they are completely separate from the fire bottle system.

I have a "you're on fire" alarm (heat sensors) and then a separate "the fire bottle just went off and hopefully the fire is out" alarm.

[MikeP]

I think CO2 may be getting a bad rap that it doesn't deserve.

CO2 is an EXCELLENT fire supressant. It leaves no residue, will shut down an engine automatically, and is completely non-toxic.

Just like any inert gas, when it displaces the air in the room, there is no longer any oxygen to feed the fire or to breathe. So you can pass out for lack of oxygen, but not due to any toxicity of the CO2. You can breathe CO2 just fine if there is sufficient O2 in the mix to sustain life. But the whole point of the system is to ensure that there is NOT enough O2 to sustain the fire (or you).

Obviously, as has been much stated, if you are in the engine room when the system discharges, you need to leave. It's not like you are going to immediately fall over but you NEED TO LEAVE immediately and get up on deck.

The disadvantage of CO2 is that it takes a larger bottle to provide the same coverage of "newer" chemicals and is therefore more expensive to use/refill, more difficult to man-handle for weighing or other purposes and it takes more space. The only reason I would consider replacing the CO2 system is if the bottle itself is no longer capable of passing inspection. Since our 53 (I assume all Hatts?) has a separate engine shutdown that is triggered if the fire system activates, there is no need to add that capability which is required with a non-CO2 system.