"Early" fire detection annunciator?

Has anyone rigged up a sensor that would trigger a "High Engine Cowl Temp" LED that could be used as an advanced fire warning in their RV?

Friend of mine and I were talking about a recent event I had with smoke in the cockpit and it make me start thinking of ways to better "fire proof" the RV.

Yes. Used two thermal fuses made of solder on a non conductive block. Wired in such a manner as both had to open to trigger the warning light. Mounted the links on the lower aft engine mount tubing, where I thought hot gasses and flames might travel leaving the cowl. Never activated, false or actual, in 1500 hrs. I removed it at that time. I don't have first hand experience (maybe someone who's actually had an engine compartment fire will comment), but I believe you'd smell and possibly feel the effects of a fire about as soon as any heat detecting system activated. So I don't miss it.

If you really want to go there, look at optical flame detectors. They typically use UV + IR to detect actual flame, instead of just heat. I saw a demo at one of our rotary engine seminars several years ago. They detect flame long before you'd see any significant heat rise in the tornado blowing through a cowl.

Charlie

Thermal Fuses

I placed two thermal fuses rated about 450 degrees F about midway up on my firewall, very near the fuel pump. The fuses are in parallel on a terminal block with one end to ground and the other as an input to my Dynon D180. If they both melt I lose ground and my annunciator displays "FIRE".
These fuses are typically used in appliances like hair dryers.

Don

cfiidon said:

I placed two thermal fuses rated about 450 degrees F about midway up on my firewall, very near the fuel pump. The fuses are in parallel on a terminal block with one end to ground and the other as an input to my Dynon D180. If they both melt I lose ground and my annunciator displays "FIRE".
These fuses are typically used in appliances like hair dryers.

Don

Click to expand...

Oh, that's even easier than what I did with an LED! I might reinstall and connect to my Dynon.

I installed a additional GRT OAT probe in the cowl exit area figuring if there was a fire in the engine area during flight, this temp would rise quickly. The probe is connected to a spare temperature port on the GRT engine monitor and an alarm programmed at the highest possible value, around 500F. This temp normally runs around 160F.

Bevan